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REPORT ON PARAGRAPH 3 OF TERMS OF REFERENCE.
“3. To consider and advise as to the main naval requirements of each type, e.g., speed, endurance,* armament, protection, displacement, special fittings, and equipment, etc., giving reasons for each requirement. In so doing, to investigate thoroughly and report upon the naval and tactical considerations arising out of:-
(a) The increased efficiency of projectiles over armour;
(b) The increased efficiency of hull protection against the effects of torpedoes;
(c) The part likely to be taken in future by aircraft, both in attack and defence.
(in connection with (a) and (b), certain secret papers will be referred to the Committee).”
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Report on Paragraph 3 of Terms of Reference is dealt with under the following headings:-
The BATTLESHIP.
The BATTLECRUISER.
The LIGHT CRUISER AND CONVOY CRUISER.
The FLEET AIRCRAFT CARRIER.
The DESTROYER AND FLOTILLA LEADERS.
The SUBMARINE.
P. and P.C. BOATS
C.M.B.’S.
D.C.B.’S.
General remarks on:-
Armament.
Machinery.
Fuel.
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INDEX TO THE BATTLESHIP.
GENERAL CHARACTERISTICS |
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*Admiralty letter M.03895 of 26th July, 1919 |
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INDEX TO THE BATTLESHIP – continued.
MAIN ARMAMENT –continued. |
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STAR SHELL GUNS |
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SEARCHLIGHTS |
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INDEX TO THE BATTLESHIP - continued
GUNNERY AND TORPEDO CONTROL POSITIONS. |
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CONNING TOWER |
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PROTECTION. |
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INDEX TO THE BATTLESHIP - continued
DISPLACEMENT. |
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SPECIAL FITTINGS AND EQUIPMENT. |
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THE BATTLESHIP.
GENERAL CHARACTERISTICS.
1. Importance of Protection and what it embraces.
As the first point to be included under the heading of “General Characteristics,” we wish to emphasis the importance of protection in its widest application, that is to say, the arrangements provided to keep a ship afloat in spite of sever damage from any weapon which may be used against her. In our opinion, a ship is of no value as a Capital Ship unless she is capable of receiving heavy blows without sinking, blowing up, or loss of motive power, and of being kept upright in spite of underwater damage, and thus of continuing to steam and fight and being able to give and receive further punishment without the disadvantage caused by heel. From these requirements others follow as a matter of course; these include good torpedo protection and water-tight subdivision, which should be as uniform as practicable throughout the ship; strong and well-supported bulkheads, which can be relied upon to remain water-tight when the compartment they enclose is flooded; facilities for rapidly correcting heel and, more slowly, for correcting trim; pumping power sufficient to deal with considerable leakage through damaged bulkheads and decks.
2. Relation of Size and Form to Protection. – Unless the design and equipment of the ship are such that she can be considered to be safely protected from under-water attack, size should be limited in order to reduce the torpedo target and lessen the magnitude of the disaster in case she is lost. Likewise special attention should be paid to manoeuvring powers in order that she may be able to avoid torpedoes If, however, safety against under-water damage is made the first consideration in the design, then length and handiness to manoeuvre may come second.
3. Gun Platform. – The ship should be a good heavy gun platform whatever her size.
4. Limitations to Beam and Draught. – In order that the Constructive Department at the Admiralty may be in a position to produce the best designs for new Capital Ships, we strongly recommend that the limitations as to beam, which have hitherto handicapped us, be removed to the fullest possible extent. We are informed that the limiting beam for ships using the Panama Canal is 106 f. and the beam of the new U.S.A. battleships of the “ Connecticut” class and battle cruisers of the “ Lexington” class, 106 ft. and 105½ ft. respectively, confirms this figure. We consider that this limit should be adopted for our new capital ships, and, with it, a reduction in draught to 30 ft. in the deep-load condition, or to such draught in the future as will permit of passage through the Suez Canal. With these dimensions, both of the principal artificial waterways of the world will be open to our ships, a factor which may be vital in a future war. But, apart from the above, increased beam and decreased draught of first-rate importance as affecting design and stability, while decreased draught also confers navigational and possibly operational advantages. The wider ship is more easy to protect structurally against under-water damage because of the greater space available, stability is likewise improved by the larger beam; speed will not suffer by the change in shape if we can judge by results in “Revenge” class or the speed of German battleships.
5. Docks. – We realise that the policy recommended above is a serious one from the point of view of our existing docks, but, after full consideration, we do not think this should be allowed to weight against it; the advantages to be gained in the matter of ship efficiency are so far-reaching that we feel the step to be an essential one. It follows that, if our proposals are approved, orders for new floating docks will be required at the same time as those for new capital ships.
The Portsmouth floating dock, having a lift of 32,000 tons, cost £258,000 in 1914, of £8 per ton lift; the same dock would now probably cost three times as much. Allowing £6,000,000 for the cost of a new battleship, a floating dock with 50,000 tons lift could be built for approximately £1,200,000 or 20 per cent. of her cost.
6. The serious disadvantages of being without adequate docks was shown clearly in the early months of the war before the floating docks were taken to Invergordon and the Tyne, and the Rosyth docks were completed. Had they not been available
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the Fleet could not have been kept so efficient, ships proceeding to distant ports to dock would have been unavoidable exposed to additional dangers from submarines and mines, and much delay must have taken place in getting ships repaired after damage.
7. Displacement. – We should prefer a ship having a displacement of approximately 35,000 tons in the deep-load condition, but fully realise the figure can only be determined after all the main characteristics of the ship are decided; it is mentioned, therefore, as an indication of what the Committee consider to be desirable.
8. Experimental Ships needed to Test Designs. – So much has occurred during the war to show up old weaknesses in our material and to improve destructive agents of all kinds, that we believe extensive trials are needed to prove or disprove new theories of ship design. We recommend, therefore, that two of the older battleships most suited for the purpose be selected for experimental work in connection with construction and protection and all that these involve. The lessons learned would not be only defensive. Weapons would improve as a result of severe practical tests. That there is a need for such tests is borne out by the facts that it was only after Jutland that we realised our heavy projectiles needed improvement, and that our magazine protection was dangerously inadequate.
9. Summary of Main Characteristics. – The principal features which should be found in the design of a battleship are discussed at length under their separate heads in the remarks which follow, but, broadly, they may be summarised as follows:-
The design should be such that the ship is strong in all essentials; no primary characteristics should be sacrificed for a secondary one. In armament, protection, endurance, speed and equipment she should compare favourably with contemporary foreign ships she need not necessarily be superior in each of these, because in order to keep down cost, displacement and therefore dimensions must be moderate. The conception takes the form of the “Royal Sovereign” class, but with improvements, as described hereafter.
10. Report follows Terms of Reference. – The order in which the main naval requirements of the battleship are dealt with is similar to that in which they are given in our Terms of Reference.
SPEED.
11. Reason for High Speed. – Superior speed always confers advantage for tactical reasons; high speed greatly increases the mobility of a Fleet. In war it is always the unexpected that happens; battle at sea is largely a contest of wits, and it is impossible to foresee every eventuality. At Jutland, for example, the manner of the Battle Fleets meeting was uncertain up to the last moment and, after contact was made, rapid deployment was of supreme importance to the British Fleet. The larger the Fleet the more important becomes speed, or the whole becomes unwieldy, due to the time required to form line of battle. Thus the wing columns, which will probably be composed of the newest and most powerful ships, need some excess over the older ships in the centre; otherwise new battle tactics need devising to compensate for unavoidable delay in deployment.
12. Speed Recommended. – We recommend at the present time a speed of 23 knots for the Battleship, this being a slight advance on the “Revenge” class, although not as much as in the “Queen Elizabeth” class. It is also the designed speed of the new U.S.A. battleships. In our opinion, our ships must have at least equal speed to those of foreign navies.
13. Relation of Speed and Draught. – This speed of 23 knots should be obtained in the deep, i.e., the real normal load condition, which should imply full sea-going complement and equipment of ammunition and stores, but with only two-thirds fuel on board. Speeds obtained at lighter draughts may by valuable for constructive and engineering purposes as affecting designs, but they are only misleading in working out tactical and strategical problems.
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ENDURANCE.
14. Reason for Large Endurance. – The two strongest foreign Naval Powers are now the U.S.A. and Japan. War against either would entail operations at a great distance from home and probably also at a distance from the main Fleet base.
Whatever be our relations with these countries, we should possess a Fleet capable of guarding our interests in any part of the world, and it is incumbent upon us to design ships for that purpose.
15. Endurance Recommended. – We recommend, therefore, that our battleships should have an endurance amply sufficient to steam across the Atlantic and back, or from Canadian Harbours to the West Indies and back; or from Singapore to Japanese waters and back; and put this at 6,000 miles.
We recommend 14 knots as the speed to be used for calculating endurance, giving a fleet speed of 13 knots on passage.
It should be noted that the official endurance is 15 per cent. less than the maximum distance which can be steamed for the total quantity of fuel carried, this margin being allowed for unfavourable weather and for fuel which is unavailable, e.g., the oil fuel pumps will not take the tanks down to the last ton or so. Thus a ship having an official endurance of 6,000 miles must carry fuel sufficient for rather more than 7,000 miles.
If 15 per cent. of the displacement be taken as being as much as can be allotted to fuel in a battleship, a ship of 35,000 tons can carry 5,250 tons, which should be more than sufficient to steam her 7,000 miles at 14 or 15 knots. This is based on the consumption of “Royal Sovereign” and “Queen Elizabeth” classes being 10½ tons per hour at 15 knots, and takes into account a heavier ship but with improved economy owing to geared turbines.
MAIN ARMAMENT.
16. Policy. – We consider that it would be very erroneous policy to permit any foreign navy to out-gun ours.
By out-gunning is meant the power, firstly, to hit hard enough to diminish an opponent’s fighting power and, secondly, to hit frequently enough to destroy it.
17. The out-gunning of one ship by another does not necessarily follow because her guns are of larger calibre, or because they are more numerous; but, with the continuance of fairly uniform progress in gun armaments by all nations, we should be very sure of our ground before allowing other navies to get ahead of us in either respect. The probability is that, within reasonable limits, a ship mounting heavier guns or a greater number of guns of equal calibre than her opponent will have the advantage. It has generally happened that, with an increase in calibre, the number of guns or number of turrets, or both, has been reduced. Consequently the adoption of a 16-in. gun and triple-gun turrets by the U.S.A. for their new battleships is a notable development.
18. Factors affecting Strength of Armament. – If we could fix on a certain thickness of armour as being the maximum likely to be employed in a ship for some years to come, and if we also decided the maximum range at which we wished to be able to penetrate this armour, the minimum calibre of gun necessary to do the work could be determined. Having arrived at this, and knowing approximately the weight of main armament which can be carried for any particular size of ship, various armaments could be compared.
In practice, however, decision as to armament is always affected by other considerations, the principal one being armaments of foreign ships. A natural tendency exists to go one better, especially in calibre, in the belief that the heaviest gun is the most likely to be successful when put to the proof. But there is a limit to this because no one would agree to the adoption of such a large calibre that number of guns become disproportionate, e.g., two 24-in. for eight 15-in.
We have to recognise, therefore, that the result is always a compromise and is always likely to be, even if radical change in gun design materialises, for this would soon be universally followed.
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19. Possibility of New Developments in Gun Design. – An example of radical change in gun design was furnished during the war by the German long-range guns which bombarded Paris at a range of 75 miles.
These guns are of 8.28-in. calibre, are believed to have had a muzzle velocity of 5,000 f.s., and fired a rifled shell of very pointed shape (10 c.r.h.). The high velocity could only be attained by high pressure and a shell light in proportion to the gun and weight of propellant; therefore the gun was much heavier and much longer than normal for the same calibre, while the shells were made of specially strong (zirconium) steel.
It would be unwise to dismiss guns of this type as freaks, because, whatever their disadvantages in respect to accuracy and the small burster which can be carried in their shell, they do mark a definite stage forward in the attempt to increase the power of the gun.
In the following paragraphs, which deal with naval guns of the present time, endeavour is made to analyse gun power, and ti will be seen how much importance attaches to high velocity as a means of obtaining a large danger space and, therefore, of hitting, and a high striking velocity in order to penetrate armour.
It would be premature to say that the limit to calibre is in sight, but at the present rate of progress it cannot be very far distant. When it is reached, or more probably before, means will almost certainly be found to increase gun power in some other way. The obvious way is by increasing muzzle velocity, which is what the Germans did.
The invention of the rifled B.L. gun in the days of muzzle loaders was the last great step forward; the next is hardly likely to be so revolutionary.
In the belief that progress must ultimately lie in the direction indicated, we recommend that research on these lines be commenced, quite irrespective of the trials we have recommended in paras. 25 and 31 for guns of normal design.
Calibre Considerations.
20. Meaning of Gun Efficiency. – The first thing to be decided is the power requisite for the individual gun; that is, its efficiency as an engine measured by its ability to hit with the shell it discharges and the ability of its shell to penetrate and to destroy.
There is no difficulty in working gun machinery. What men of one nation can do those of another can, but nationality and training really tell under fire. If the gun is not the best, the most efficient and the most modern, and is put against one that is, too much is being asked of the human element, whatever the result may be.
21. Ability to it depends on range, accuracy and danger space; to penetrate on armour-piercing qualities; to destroy on the destructive effect of the shell burst. These will therefore be considered separately.
22. Range. – There is no doubt that the 15-in. gun and ship’s mounting can be developed to give the maximum range required for ship versus ship action.
23. Accuracy. – Accuracy has two sides: the absolute accuracy of the gun, as determined on the proving ground, and the accuracy of the armament in the hands of the personnel.
As regards the individual gun, it is highly probable that the larger the gun the better the accuracy. This is not only based on experience, but the effect of manufacturing inexactitudes is proportionally less, and the ballistics are more stable because the projectile is less affected by wind and other external causes.
As the accuracy of a gun is measured by its performance, the accuracy of the projectile and propellant have to be taken into consideration. These are dealt with elsewhere in our report, but may be mentioned here because the regularity of internal ballistics depends upon the propellant. With a low muzzle velocity, as given to the 15-in. Mark I, accuracy is good, either because the vibrations set up in the chase on firing are insufficient materially to affect the steadiness of the flight of the shell, or because a low mean difference of velocity between rounds can be obtained (2 f.s.); with a higher velocity, vibration will be greater and a larger mean difference in
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velocity from round to round must be expected, accuracy will therefore fall off. The point is that the gun, projectile and propellant are one, and to get the best result from the gun the ammunition must be suited to it.
The accuracy of the armament in the hands of the personnel is remarked upon in para. 39.
24. Danger Space. The figures for the existing 15-in. gun are low and could be improved by reducing the weight of the shell so as to obtain a higher muzzle velocity; but this advantage will be gained t the expense of burst effect, and possibly of accuracy and life of gun. What can be done with a 15-in. gun can be done also with larger calibres, so the latter will retain other advantages they already possess.
So far as we are able to judge, the best obtainable danger space figures for new designs of all calibres, 15-in. to 18-in., with normal as opposed to exceptional ballistics, would not differ appreciably form one another (although decidedly superior to the 15-in. Mark I) and, therefore, from this point of view, there is little or nothing to choose in respect to calibre.
We wish to emphasise, however, that every yard of danger space is so valuable, especially at long ranges, that it is a factor which should always be given great weight. The reasons are that it minimises the effect of errors in sighting and compensates also for inaccuracy. The former is self-evident; the latter is explained by the relations between danger space and the 50 per cent. zone, for, if the zone is 300 yd. a danger space of 30 yd. must give more hits than one of 20 yd.
25. Armour-piercing Qualities. – These have become very difficult to forecast for various reasons, which are briefly stated below.
For a long time progress in the attack or armour by shell was so slow that armour improved in quality at a greater rate, culminating with the introduction of K.C. armour. During this period various formulae were built up to enable penetrations and resisting powers to be calculated, but only normal impact was considered.
It was generally agreed that striking energy was the principal factor in obtaining penetration, and thus, for any two shell with approximately similar striking velocity, the heavier had the advantage.
With the introduction of larger calibre guns, immense improvement in shell, and a wider outlook on the question generally, including the attack of armour by shell striking at angles to the normal, these old formulae have been shown to be obsolete, and up to the present insufficient trials have been carried out to enable new formulae to be constructed. There is therefore now no recognised accurate method of assessing results of hypothetical guns and shell; trial si the only means by which reliable information can be obtained.
Such trials as have been carried out do show, however, that striking energy may be by no means f the same dominating importance that it used to be; better results have been obtained by combining with a high striking velocity a design of shell able to resist the stresses set up on impact with armour. Long, i.e. heavy, shell are more difficult to get through an inclined plate that shorter, i.e. lighter, ones because the base may be wrenched off in the effort of the shell to turn in the plate. A 13.5-in., 1,250-lb. APC. shell is just as good, if not better, than a 13.5-in. 1,500-lb APC. Shell against a plate at 20 deg. to the normal, in spite of lesser striking energy.
The fact is, we don not know what relation between the weight and diameter of a shell is best for all-round A.P. qualities and, until this is known, we cannot really decide the best design of shell for our heavy guns. Nor do we know the limit of calibre beyond which A.P. qualities fall off on account of the size and length of the shell.
The difference in weight between the shell supplied to British and German 15-in. guns, 1,920-lb. and 1,653-lb. respectively shows what different views are held as to the best method of obtaining maximum efficiency from heavy guns.
26. In spite of what has been written above, in default of anything better there is no alternative but to make us of the old methods of calculation in the belief that figures deduced from them are better than nothing.
The muzzle velocity of our 15-in. gun is low compared to some foreign guns, the U.S.A. 16-in. for example, and although it fires a relatively heavier projectile, its calculated penetrations are decidedly smaller, e.g., 14.1 in. at 15,000 yds. as against
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19.6-in. (See table in next para.) Our 15-in. has actually penetrated 10-in. at 20 deg. to the normal at 15,000 yds. An improved design of 15-in. gun would undoubtedly obtain better results, but these will not quite come up to the U.S.A. 16-in.; an the latter improved would probably retain much the same margin of superiority. We understand that U.S.A. shell are equally as good as ours, so that we have nothing in hand in that respect. There is, however, no object in mounting guns which are unnecessarily powerful, and this appears to be the critical factor. With armour far behind the gun in efficiency, ships cannot carry it either of sufficient thickness or in sufficient quantity to keep out modern shell. We think it probable that armour and methods of disposing it will improve, but there is no immediate prospect of the former and it is also probably that guns and shell will improve. Our 15-in. Mark I gun, as already shown, is distinctly inferior in penetration to the U.S.A. 16-in. and, allowing that ships can quite will carry side armour 14-in. thick abreast their vitals (“Baden” has 13¾-in.), it is not capable of delivering a knock-out blow at ranges greater than 15,000 yds.; this range for the American gun is well over 20,000 yds.
27. Table showing Calculated Penetrations of K.C. Armour.
Gun. |
10,000 yds. |
15,000 yds. |
20,000 yds. |
25,000 yds. |
15-inch Mark I (as now mounted in H.M. Ships.) |
17.7” At 7° |
14.1” at 13° |
11.5” at 21° |
9.6” at 31° |
15-inch 50 calibre |
22.5” at 5° |
18.9” at 9° |
16” at 14½° |
13” at 22° |
16-inch American |
23.4” at 5° |
19.6” at 9° |
16.4” at 14° |
13.3” at 21° |
16-inch New Gun |
23.9” at 7° |
20.3” at 9° |
17.3” at 14½° |
14.3” at 21½° |
18-inch Mark I (“Furious” Guns) |
21.8” at 7° |
18.7” at 12½ |
15.1” at 19° |
13.8” at 27° |
18-inch New Gun |
25.5’ at 6° |
22.1” at 10° |
19’ at 15° |
16” at 22½° |
As already explained, this table is not reliable and the figures it gives cannot be checked with certainty except by actual trial. It shows, however, what great advantage the heavier guns possess theoretically.
28. Burst Effect. – This depends on size of shell, nature and weight of burster; obviously, if gun and shell designs are normal, and bursters of similar explosive, the heavier gun fires the heavier shell and gets the advantage. But burst and A.P. qualities to some extent conflict because, if shell are made very strong in order to penetrate armour, their fragmentation on bursting may be poor.
29. Summary. – To obtain results from a 15-in. gun comparable to those from a 16-in. or larger, the 15-in. must either be forced or lengthened to increase muzzle velocity, or some radical change in ballastics must be made. A forced gun loses in accuracy, which means loss of hits. If the length of a 15-in. gun can be increased, so probably can that of a larger, consequently the gain will be similar; it is merely a question of whether the increased weight necessitate by greater length gives results sufficiently better to justify it. There is no immediate prospect of radical change in ballastics materialising; it would need several years to investigate and try to a conclusion.
Research and experiment carried out on a large scale may prove that there is limit of calibre and length beyond which there is no advantage n going, or which is imposed for manufacturing reasons. Difficulties have in fact already been experienced with ammunition for the 15-in. gun, and the plant now available in the country is inadequate to manufacture guns of much increased calibre in numbers; but we are on the way to overcome the former and the latter is only a question of outlay. No sufficient reason is see to suppose that the limit of calibre of maximum efficiency has yet been reached.
30. Other Arguments which may be cited for and against increase in calibre include the following:-
For:- The moral effect of the heavier gun is considerable, not so much perhaps in action (because few see what is going on) but as engendering confidence in the material and in the forethought at the Admiralty. Officers and men do not doubt their ability to make the most of the material provided but they do undoubtedly compare that material with that of other ships, and especially foreign ships, which they may have to fight. This
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argument can, of course, be exaggerated unless equality is assumed in some respects, for example a 15-in. gun able to penetrate the enemy’s armour t any range, firing tie as fast and having twice as much ammunition as (say) an 18-in. gun would be a better weapon for a ship.
We think that, during the war, the 13.5-in. and 15-in. gun ships were of great moral strength to us, for we know that the German personnel with their 12-in. guns felt themselves inferior in spite of all that was told them to prove the contrary. Von Tirpitz completely failed to convince German naval opinion on this point.
Against: - Increased calibre by one nation has inevitably led to others following suit. Both the U.S.A. and Japan have adopted a 16-in. gun, and it is said that the U.S.A. is making an 18-in. or it ma be a 20-in. gun for trial. If we join in the competition, we may be forced to follow step by step, or we could take the lead by making a large increase, in the hope that this will prove to be the limit for a number of years.
With small guns weight is less all round, thus, affecting size of ship and reducing expense. If size of ship and cost are of secondary importance more guns might be carried for the same weight.
Manufacture and supply of ammunition is simplified by adherence to one calibre for as long as possible; where supply involves transport over long distances by sea, standardisation pays both economically and practically because occasional delays or losses of transports will not be of supreme importance. From this point of view it is also better to take one large step instead of several smaller ones.
Peace cost for practice ammunition and replacement of guns will be smaller.
31. Conclusion. – We consider that the 15-in. gun now mounted in H.M. ships is insufficiently powerful to be pitted against the latest foreign guns.
We consider, therefore, that the right policy is to increase calibre so that our guns may at least equal those of foreign Powers in range, danger space, and armoured penetration, whilst at the same time retaining accuracy.
We think that it would be wise to commence at once investigation of an 18-in. gun, even if there is no immediate intention to adopt it. It is not as if an 18-in. gun had not already been built; the step has been taken and is therefore more likely to be followed by other nations. By doing so we should gain information which will enable us to build efficiently if we need to, and will be nearly as valuable for new guns of a rather smaller calibre if this be ultimately decided upon.
We recommend, further, that trials be initiated at once with the 15-in. gun in order to obtain full information on the relative merits of heavy and light shell within wide limits, which may serve as a guide for the heavier gun, and, if the results are important, might also enable us to re-arm our 15-in. ships with shell of superior types.
The Gun Mounting.
32. Maximum efficiency cannot be obtained from the gun unless its mounting and all that this includes, are capable of supplying it with ammunition at a uniformly rapid rate, or enabling it to be trained and elevated with precision, and of permitting adjustments to be made to correct for inaccuracies peculiar to an individual gun or its ammunition.
33. Rate of Fire can only be judged comparatively; there is no theoretically best. It has always been recognised as a factor of primary importance because rapid hitting breaks down the enemy’s resistance; the war showed that with fairly evenly-matched ships nothing short of maximum rapidity was sufficient for success.
At the present time it is generally recognised that the rate of loading obtainable from a 15-in. turret is a few seconds slower than from a 13.5-in., and from a 13.5-in. than from a 12-in. This, no doubt, is due in part to the heavier weight of moving parts all through the turret, but there is reason to suppose there are other causes.
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34. Speed of Loading depends upon Design of Machinery and Power available to work it. – There is no uniformity either of turret machinery design or source of power amongst the Navies of the Great Powers; each has its own designs and the power use may be hydraulic, electric, pneumatic, or a combination of the three. The fact that differences exist shows that finality has not been reached.
In our Navy, the introduction of director firing led to difficulty being experience in maintaining hydraulic pressure, due to the number of machines put in operation simultaneously in order to reload after each salve. The older ships were undoubtedly under-pumped and, in order to improve matters, pneumatic run-out has been substituted for hydraulic in a number of mountings. But this does not afford a complete explanation, because the design of the pump and its steam engine does not lend itself to maintenance of high pressure under very variable loads; its speed falls so low that it does not respond sufficiently quickly to sudden large demands.
Another point is that, unless each turret has its own pump, some turrets are nearer the source of power and therefore better supplied than those more distant. Again, all turrets are not on the same level and it stands to reason that there must be greater loss of pressure in the longer pipes of the higher turrets.
35. Arrangements for Transport of Ammunition. – The transport of ammunition will affect rate of loading only in any portion of it has to be man-handled; at present, all cordite is man-handled in the magazine and handing room. For the 15-in. Mark I gun the weight of the charge is 428 lb., made up in four quarters for convenience. These 107-lb. charges are about the limiting weight for man-handling. An 18-in. charge would weight 700 to 800 lb. If calibre is increased, therefore, either the charge must be made up in sixths or power working must be adopted in the magazines and handing rooms.
36. Training Machinery is not at present satisfactory as trouble is experienced, especially in the heavier turrets, with the long spindles and frictional gear. The control is good.
37. Elevating Machinery and Control. – We believe these to be very efficient and have no suggestions to make in respect of them.
38. Summary. – We do not think that a heavier gun than the 15-in. can be ruled out on the grounds of insufficient rapidity until it has been proved that it is impracticable to provide machinery to load it sufficiently quickly.
39. Accuracy of Armament. – As, in practice, guns are not fired singly, hits depend less upon the accuracy of the individual gun than upon the accuracy of the armament as a whole That the latter is much less than the former is shown by the very small percentage of hits obtained to rounds fired. The causes and effects of inaccuracy when the whole or part of the broadside is fired simultaneously are therefore important.
Hits are obtained by correcting the sights after seeing the fall of shot, and the fact that the broadside has “spread” assists this correction. If spread is very large, hits per salvo will be few, or even nil, because the target may be straddled without being hit. If the spread is nil, few hits will be obtained, owing to the difficulty of placing the mean point of impact exactly on the target. Consequently, some minimum spread or dispersion is advantageous.
Spread is affected by the accuracy of the individual gun, the accuracy (or calibration) on the broadside and the average error of the personnel. Considering existing guns, spread is larger than the most advantageous minimum, which is generally held to be 150 to 200 yds. It is not sufficient for the individual gun to be accurate if our methods of calibration are not; in the widest sense, calibration includes allowances for decrease of muzzle velocity due to wear, temperature of magazines, etc. The error of the personnel, which is invariably the largest of the tree, varies with the skill and knowledge of the personnel, and of the control personnel, in a special degree.
So far as ship design is concerned, no more can be done than to provide control positions, which are the best that experience can evolve, and efficient arrangements for controlling magazine temperatures.
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Considerations respecting Number of Guns.
40. The number of guns which can be carried by a ship is governed by their weight (equals calibre) the manner of arranging them, the displacement and other primary characteristics. Because volume of fire is of first importance, the number of guns should be as large as possible.
41. Minimum Number for Efficient Fire Control not the Deciding Factor. – For efficient fire control the least number of guns which should fire in each salvo is four; this necessitates a ship carrying eight guns. But it is not sufficient to accept this; the real question is what number are needed to prevent a ship being out-gunned by a foreign contemporary. As the director system is no longer exclusive to us, our fire control methods are known in their entirety to the U.S.A. Navy, and as we have no reason to think that our gun mountings are capable of more rapid fire than those of other navies, it follows that we shall be out-gunned unless we either have an equal number of guns or mount a smaller number in a more efficient manner.
42. Number of Turrets carried in Modern Ships. – To judge by recent construction, both at home an abroad, it appears to have been more or less accepted that four turrets is as many as can be built into a Capital Ship without unduly increasing both size and cost or sacrificing some other very important characteristic, and that two of these turrets should be forward of the machinery and boiler room spaces and two aft.
43. This arrangement is a development founded on experience of earlier types such as “Dreadnought” and “Indomitable,” “ Neptune,” “Orion” and “Lion,” and finally “Repulse.” The fifth centre-line turret, which first appeared in “Orion” class and was continued in later classes mounting 13.5-in. guns, was an undoubted advantage from the point of view of offensive power; but, with the introduction of the 15-in. gun and at the same tie a demand for higher speed, it was omitted from later ships in order to keep down size. All navies have been faced with this problem and although some, notably those of the U.S.A. and Japan, adhered to a fifth or even a sixth turret for some of their later designs, each now appears to have come round to the four-turret battleship, eg., U.S.A. “Colorado,” “South Dakota” and “North Carolina” classes (10 ships); Japanese “Kaga” class (four ships); Italian “Caracciolo” (one ship); German “Baden” (two ships).
44. Recommendation. – However desirable the four-turret design may be for constructional reasons, we consider that these must be subordinated to military reasons if we are unable to mount efficiently in four turrets the number of guns required. Should this prove to be the case, we think that if a six centre-line turret design is altogether impracticable for the ship of the size we are recommending (approximately 35,000 tons displacement), a gun margin against us of not more than 12 guns in four triple-gun turrets to 10 guns in five pair-gun turrets should be accepted. Although gun power would be less, there would be advantage in distributing the armament into a larger number of separate units.
45. Number of Guns mounted per Turret in Modern Ships. – Like our ships, all the foreign battleship mentioned in para. 43 have pair-gun turrets with 15-in. or 16-in guns, except the six U.S.A. ships of “ South Dakota” and “ North Carolina” classes, which are to have triple-gun turrets. These however are not the first vessels to be so armed, since the triple-gun turret was a feature in the design of earlier U.S.A. ships as well as in Austrian, Italian and Russian.
Note. – The latest projected French battleships were to have four-gun turrets; the designs must have been worked out.
46. Triple-gun Turrets. – Unfortunately we have very little reliable evidence upon which to base an opinion as to the practical advantages of triple-gun turrets. None of the ships mounting them have been in action during the war and we know nothing of the results of their target practices. Years of experience with the pair-gun turret have enabled us to produce an efficient type, easy to maintain in good order, simple to manipulate, and capable of prolonged working at a uniform and rapid rate of loading; doubtless, many improvements can still be made, especially in speed of loading, but taken generally and relatively to foreign navies, these claims do not exaggerate. The preference for the pair-gun turret has not been altogether conservatism; designs for a triple turret have been considered at various times during
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the past 12 years and have been turned down on account of unsatisfactory features; neither the Germans nor the Japanese have adopted them, though we must assume they have fully considered the problem. We think it would be unwise to alter radically our turret design before being sure that the advantages to be gained by the change make it worth while.
47. The chief points to be considered in respect to a three-gun turret are whether:-
(i) The third gun will enable a great rapidity of accurate fire to be obtained;
(ii) The present high rate of loading can be arranged for reach gun;
(iii) The turrets as a whole will be as simple and reliable as the present type.
(iv) With guns of 16-in. or larger calibre, ti would not be more economical of weight and space to mount five pair-gun turrets rather than four triple.As regards these:-
(i) Assuming that the time of loading is the same for all guns of a turret, director firing should ensure that a proportionately greater volume of fire is obtained from three guns than from two; it requires to be proved that accuracy will not suffer materially on account of the discharge of two or three guns mounted close together as would be necessary to take full advantage of the number of guns in the armament; trials are therefore necessary.
(ii) and (iii) are questions principally of design and until satisfactory designs have been produced there is little profit in offering opinion; probably, however, useful information of practical working of triple-gun turrets could be obtained from foreign navies. It is on threes three accounts that the Committee has pressed for trials to be carried out in the Russian battleship “General Alexieff.”
(iv) is a constructive question and we have been informed by the D.N.C. that it would be lighter to mount ten 16-in. guns in pairs than twelve as triples; but, to be able to give an authoritative opinion on the matter, the designs need working out fully so that it may be seen how they compare in the matter of space and protection.
48. Conclusion and Recommendation. – We are not prepared that new battleships should carry only four pair-gun turrets as against the U.S.A. four triple-gun turrets, the adverse preponderance would be altogether too great. Nor are we prepared to advise the acceptance of any margin against us if our number of guns per turret is the same as in foreign navies, i.e., if we adopt triple-gun turrets and 16-in. guns we should mount 12 guns in four turrets similar to the U.S.A. If the U.S.A. reverts to pair-gun turrets, we can be content to adhere to them.
If, however, trials should prove that the triple-gun turret is not satisfactory, then we consider that, provided our ships have the superiority in numbers of turrets, we can then allow a gun margin against us of not more than 12 to 10, i.e. a British fire pair-gun turret against a foreign four triple-gun turret ship.
Outfit of Ammunition
49. War experience not sufficient guide. – The war threw very little light on this question because, except at the Battle of Falkland Islands, no action between Capital Ships was fought to a finish. At the Falklands “Invincible” and “Inflexible” had little ammunition left when the action was over although they had filled up to maximum stowage before leaving England, “Inflexible” actually firing 661 rounds, 21 more than her pre-war outfit.
50. Causes affecting size of outfit. – The range of opening fire has much increased as the result of war experience and is now limited only by ability to spot. Development of aerial spotting may increase it further; director firing has greatly improved rapidity of fire.
Accuracy has progressed due to the director and to experience gained in firing at long ranges. It is not, however, sufficient by itself to obtain hits at long ranges, because the danger space of the target is so small.
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It follows therefore that if fire is opened at extreme ranges and continued at the normal rate, a large expenditure of ammunition must be expected before decisive results are obtained.
51. Increase during War. – Our ammunition outfits were increased during the war from 80 rounds per gun in all Capital Ships to 120 rounds per gun in battle cruisers and 100 rounds per gun in battleships, the extra 20 rounds in battle cruisers being carried because of the probability that these ships would have more frequent opportunities of engaging.
52. Recommendation. – Taking all circumstances into consideration, and especially the present tendency to increase the range of opening fire, we are of opinion that outfits ought to be increased and recommend 120 rounds per gun for battleships and 140 for battle cruisers.
SECONDARY ARMAMENT
53. Relative importance. – We consider that the secondary armament of a battleship must be subordinated to her essential characteristic, namely primary armament, protection, speed and size.
54. The conditions of warfare are constantly changing and developing with the introduction of new, or improvements in existing weapons. In greater or less degree these changes affect ships in almost every important particular, and consequently most of all in design. This point is mentioned here because of its bearing on the manner in which guns are mounted on board ships; every requirement cannot be me and secondary armament must to some extent be fitted in.
55. Functions of Secondary Armament. – The following include all the purposes for which the secondary armament may be employed. The order in which they are placed should not be taken as the order of importance because, the secondary armament being defensive, its object is to beat off whatever form of attack is delivered.
(i) To employ against aircraft of all descriptions which come within range, and especially against low-flying aircraft such as torpedo carrying planes.
(ii) To repel destroyer attack at night or in low visibility when time or circumstances do not permit of evading tactics.
(iii) To employ, in addition to the primary armament, against vessels of any description which may be engaged at night or in low visibility.
(iv) To repel destroyer attack during day action with other Capital Ships.
(v) To employ against light cruisers when their number is too great for the primary armament to deal with or when the latter is engaged with heavy enemy ships.
(vi) To repel attack by mosquito craft, such as coastal motor boats and distant control boats.
(vii) To employ against submarines.
(vii) For protection in harbour against any form of attack.
(ix) For firing shell required for special purposes, such as star and smoke shell.
Lastly, without including it amongst the functions of the secondary armament, may be added its moral value as a deterrent to all smaller vessels to take liberties.
Calibre of Gun.
56. Service opinion divided. – The evidence we have heard and seen shows that Service opinion is not agreed upon secondary armament questions, the chief point of difference lying in the calibre of gun to be mounted. This divergence of opinion is not new, for it existed before the war, and it is doubtless owing to the war having thrown insufficient light on the subject that opinions remain divided.
One school of though favours the heaviest gun capable of being loaded and manipulated as rapidly as our present 6-in., and the other a lighter gun having a very high rate of fire and a very easily manipulated mounting.
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Those in favour of the heavier gun, who are in a large majority, are of opinion that the necessary range will not be obtained with a gun of less that 5.5-in. calibre. Further, they consider that, in practice, the difference between the rate of controlled fire for guns varying form 6-in to 4-in. calibre is too small to be of consequence, thus leaving the advantage with the heavier gun in nearly all other respects.
Those who differ from the above and favour the smaller gun do so chiefly on the grounds that ti saves weight and space, thus permitting a larger number to be mounted, and that it has been proved by experience with the triple mounting that the lighter gun is capable of a considerably higher rate of fire than the 6-in., especially at high elevations. They do not attach the same importance to range and consider that the calibre of the secondary armament of battleships need not be influenced by the armament of light cruisers, and believe that a lighter, handier and faster-firing gun can be more effectively used against destroyers, mosquito and torpedo-carrying aircraft; the last may become on of the most serious menaces to the Capital Ship.
57. Recommendation. – We recommend that calibre of gun from which the best results are obtained firing a 100-lb. shell.
We consider that the 100-lb. shell has so amply demonstrated its effectiveness during the war that it would be unwise to discard it for one too heavy for hand loading, or for one which being materially lighter does not possess the same ballistic advantages. Both these points are dealt with more fully in the next paragraph.
We note that the conclusion drawn from recent loading trials in “Excellent” is that projectiles weighing 90 lb. are the heaviest which average men can handle quickly during sustained firing. We do not think, however, that this is in accord with war experience. Many years of experience at Gunlayer’s Test did not suggest a projectile lighter than 100 lb. for there was no difficulty in finding loaders who could work faster than the gun could be fired, and could do so quite easily. At present day mountings the breech of the gun is certainly higher than it used to be, because of the increased elevation allowed for, and therefore the effort to load is greater. But height can be reduced by different design of mounting, and loading may be made easier by the use of loading trays. If 100-lb. shell are the best for their purpose, they ought not to be given up to suit a particular design of gun-mounting or to satisfy exacting conditions of firing.
58. Effect of calibre and eight of shell upon rate of fire and ballistics: - Rapidity of fire is essential since the opportunity to fire may last only a short time and it is necessary to take full advantage of it. Experience has shown that light craft are not always stopped by a hit even from the heaviest shell; it is more important that blows should be frequent so that their effect is cumulative; rapid fire is more disconcerting to exposed personnel.
The maximum rate of fire from a battery of hand-loaded guns of medium calibre is dependent on, (i) the rate of ammunition supply, (ii) the time required for loading, and (iii) the efficiency of the control. In a big ship, which is usually a very steady platform and where there is ample room for the ammunition hoists and loading operations, (i) and (ii) will not differ very materially for medium calibre guns provided that the arrangements are good and the ammunition is not too heavy for quick handling; (iii) is altogether independent of the calibre of the gun and depends on the director layer and control officer.
In practice, the maximum rate of fire from a 6-in. (100-lb. shell) battery is, at best, eight salvos per minute; six is as many as it is safe to count upon. From a batter of 4-in. (31-lb. shell) twelve salvos per minute is possible, eight are easily obtained. The 5.5-in. gun (80-lb. shell) is a little quicker than the 6-in., but slower than the 4-in.
Long Range is necessary to meet the attack of modern weapons; the war proved that guns can be effective up to the extreme range at which their shot can be spotted. A range of 20,000 yds. is recommended. Advantage lies with the larger calibre gun and its heavier shell; in fact, unless very large angles of elevation are allowed on the mounting, guns of less than 5.5-in calibre will not give sufficient range.
Danger Space. – The importance of danger space has already been alluded to under Main Armament (see para. 24). With the secondary armament, which has to deal with fast moving targets, hitting is, if anything, more dependent on size of danger space. The heavier gun has a good deal the best of it especially as range lengthens.
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Accuracy. – Accuracy is less important for secondary than for main armament guns because range is often short and then danger space counts for more than accuracy. The point is that, although accuracy is desirable, ti should not be pressed to the disadvantage of danger space. Another reason is that inaccuracies of control are in any case likely to be so large that the accuracy of the individual gun is not of first importance. The probability is that the heavier the gun the better the accuracy.
Burst Effect should be as large as practicable to obtain decisive results. In this respect the gun firing the heavier shell must be superior.
Armour-piercing Qualities. – These may or may not be necessary for secondary armament shell as high capacity shell have greater effect on unprotected ships. The heavier gun, however, again ha the advantage.
59. Opinion. – We consider that a rate of fire of six salvos per minute is sufficient and, this being so, that the great advantages of range, facility in spotting and danger space of the heavier gun and the greater burst effect of its shell far outweigh the greater rapidity of the smaller calibre.
60. Reason for not recommending Exact Calibre. – At present, guns of medium calibre (6-in. to 4-in.) are not using shell of the full weight permissible; weights can be increased to 120-130 lb. for the 6-in., 100 lb. for the 5.5-in., 62-lb. for the 4.7-in., and 38 lb. for the 4-in. The present 100-lb. shell of the 6-in. gun has been adhered to in fact because a heavier shell could not be handled sufficiently easily. Unless therefore we are going to use power loading, it may be extravagant in weight to mount a 6-in. gun and supply it with a shell suitable for a 5.5-in., but this again does not follow because it may be necessary to employ a 6-in. gun to fire 100-lb. shell in order to obtain the ballistics we require.
61. Armament of Light Cruisers. – Another point which affects calibre is the importance of reducing the number of different calibres and marks of guns mounted in ships to the lowest practicable limit. Reasons of manufacture, supply and replacement all demand standardisation, the advantages of which for a war overseas are self-evident. It would be materially furthered were the guns and mountings of the secondary armament of Capital Ships similar to those of the primary armament of light cruisers.
62. Power Working. – The suggestion in para. 60 that power loading may be adopted for guns of medium calibre has its origin in the view that, with normal development of guns and mountings to meet new conditions, pair-gun power-worked turrets will be adopted sooner or later both for secondary armament of Capital Ships and for primary armament of light cruisers. Reasons for this already exist in the advantages to be gained in respect of economy of space, better separation of the several units of the armament, and protection of personnel both from blast and splinters.
Power working does not necessarily imply power loading, but it is not a long step from one to the other and power loading may be found preferable for primary loading. But even should it be we are strongly of opinion that hand loading must be regarded of equal importance and therefore that the weight of the shell should not be greater than 100 lb. An additional reason is that of handling shells rapidly in the shell room and at the hoists.
Number of Guns Required.
63. Requirements – We consider that the requirements are:-
An equally heavy fire must be possible from both sides of a ship simultaneously.
The arcs of fire must be large.
Protection must be given to the guns, their crews and ammunition supply from splinters, blast and weather.
64. Broadside Guns necessary. – Whenever possible attack will be made on both sides of a ship simultaneously. In nearly every case for which secondary armament is needed helm may be employed to aid in defence; the target may therefore be on one side of the ship at on momenta and on the other soon afterwards. It is impracticable to mount secondary armament guns so that they can follow
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target under these conditions, and the process of training them across the bow or stern would necessarily occupy time when time was all important, in fact, when no gun is of any use unless it is ready. Since structural consideration preclude all-0round fire from even primary armament guns and the secondary armament has to be fitted in to suit the main features of the ship, the flexibility necessary to ensure readiness on any bearing can only be ensured by mounting guns on both sides.
65. Arcs of Fire. – A large arc is required for every gun because a target may require to be engaged on any bearing, and it is unwise to rely upon one or two guns to do what three or four are necessary for. As it is impossible in practice to mount as many guns to fire ahead or astern as on the broadside, we have to consider which position of the arc from 0 deg. to 180 deg. each side should develop the maximum fire. This is important because it affects the manner in which guns are mounted. In casemates, the maximum obtainable arc is approximately 120 deg.; in turrets or in the open it is considerable more, up to 160 deg.
A strong point has already been made on the need for volume of fire against small craft; volume is dependent on the rapidity of the individual gun and on the number of guns. In our opinion, four secondary armament guns should bear on the arcs between 0 deg. and 25 deg., and 155 deg. and 180 deg., and all between 25 deg. and 155 deg.; eight guns a side are therefore required.
66. Pair-gun Turrets recommended. – We are strongly in favour of pairing guns and mounting them in small turrets for the following reasons:-
More guns can be mounted in a given space.
Larger arcs of training an be arranged for.
Better separation of units than in a battery.
Better protection of guns’ crews from blast of own main armament.
Protection afforded from fragments and blast of enemy shell.
Simplification of ammunition supply and economy in personnel resulting therefrom.
Protection from weather.
67. Positions proposed for Turrets. – The turrets should be placed on the weather decks, where they are less affected by sea and spray. We consider that the best arrangement would be for them to be on two levels, two each side of the forecastle deck and two each side of the lower superstructure deck, placed as far forward and aft respectively as the main armament will allow. Two levels permit of a heavier fire ahead and astern, as there will be no objection to guns firing over one another, while the lower guns may be able to fire under the guns of the main armament. Magazines and shell rooms must be inside the torpedo bulkheads, and hoists should lead direct to the gun-houses, not necessarily vertically.
68. Triple-Gun Turrets. – Although the adoption of triple-gun mountings would permit of a larger number of guns being placed in a given length we do not recommend them for hand-loaded guns in turrets on account of the additional space required to contain the larger crew and to enable loading to be carried out quickly.
69. Protection. – We recommend that the secondary armament turrets should be proof against high capacity high explosive shell of guns of the same calibre, and consider that nothing would be gained by adding to this.
'70. The following remarks on alternative systems of protection for secondary armament guns explain, in conjunction with para. 66, why we consider that lightly-protected turrets are preferable to any other arrangement.
The alternatives are:-
(a) Casemates, as in our older ships.
(b) A batter, as in “Iron Duke” and later classes, where the guns are separated from one another by traverses, but are not isolated.
(c) A battery, as in “ Baden,” where each gun is completely isolated from the next.
(d) Guns in shield, as in “Hood.”
(e) Guns in the open, as in “Repulse.”
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In systems (a), (b), and (c) the side of the casemate or battery has been protected by about 6-in. armour, and the sides and rear by 2-in.; the whole crew and the ammunition supply are therefore behind armour. Where the isolation of each gun from the next is complete this appears to be a perfectly logical plan. The same cannot be said when the protection is incomplete as in our batteries, system (b), and, whatever scheme may be adopted in future we consider that this should be discarded as being neither one thing nor the other; it certainly has not justified itself during the war (e.g., losses in ships of 5th Battle Squadron at Jutland). In the older vessels the object of employing armour of medium thickness on the sides of casemates and batteries was to keep out medium calibre shell, and, in later vessels, to form part of the general armour protection of the ship. In our view, if casemates or armoured batteries are retained, their side protection need not exceed 2-in. unless a greater thickness is required for ulterior reasons. While the armoured battery appears to be overdoing protection and therefore wasting weight, we think that for a Capital Ship to mount guns, which will require to be kept manned in action without protection, as in “Hood’ and “Repulse,” is going to the opposite extreme and is more objectionable, for the “Hood’s” shields only protect a few men of each gun’s crew and leave the majority and the ammunition numbers unprotected. It is directly contrary to war experience in “Southampton,” “ Chester,” and a number of German Light Cruisers.
71. Magazines and Shell Rooms. – Each turret should have its own supply tube leading direct into its magazine and shell room, which should be situated inside the torpedo protection bulkhead. The tube must be armoured, thickness depending on how placed with respect to other armour, but need not be vertical.
Direct supply not only economises men, as transport is reduced to a minimum, but should also be quicker and safe, because ammunition will not need to be transported along the gun deck. We realise that it necessitates efficient flashproof arrangements, both at the top and bottom of each hoist and for protecting the charges in transit, but we consider that these can be devised with the aid of trials.
72. Recommendation. – We recommend that there should be eight guns a side mounted in pairs in lightly protected turrets, which should be in two levels on the weather decks, each turret having its own ammunitions supply direct form magazine and shell room.
73. Whether Secondary Armaments should be combined with Anti-aircraft Armament.- We are opposed to this proposal for the following reasons:-
The Secondary Armament is required primarily against surface craft; the complications which must be added to it to fit it efficiently for A.A. fire are so extensive that the result would probably be a compromise satisfactory to neither.
Ammunition outfits would need to be much increased, because a different type of shell is required for each service. A.A. shell must be time fused.
Airplanes cannot be engaged effectively from a ship at long ranges, for “shorts” and “overs” cannot be distinguished against so small an object. For dealing with planes closing to attack with bombs or torpedoes, a very rapid firing gun on a very quickly-handled mounting is essential if the evidence we have heard is correct.
We consider, however, than an elevation of 30 deg. (or perhaps rather more, depending on the maximum range provided for) at secondary armament gun mountings will permit of these guns being employed against aircraft (especially airships), as they have been during the war, an we recommend that a small number of suitable shell be supplied for use on such occasions. This will not prevent the guns being employed for barrage fire against torpedo planes, the nature of whose attack resembles that of C.M.B.’s and D.C.B.’s.
ANTI-AIRCRAFT ARMAMENT.
74. Type of Armament required. – It was recommended in para. 73 that the secondary armament should be capable of being employed against aircraft, so far as this can be effected without sacrificing efficiency for horizontal fire against surface vessels.
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The secondary armament, however, will not bear at high elevations, and, even if it could, would be too slow (because too heavy) to deal adequately with attacks at close range, which constitute the chief danger. Consequently, we recommend that A.A. defence should be by means of:-
(a) Light guns capable of very rapid fire up to 90 deg. elevation, and mounted in the open on quick-moving mounting, and
(b) Machine guns or pom-poms for use against planes flying close.
75. Description of A.A. Gun recommended. – The gun should be of the smallest calibre suitable for its purpose, so as to fulfil the conditions mentioned above and for convenience of mounting on board. It should have a high velocity, partly in order to increase height, and partly to facilitate fire control, because a low time or flight makes it much more difficult for an aircraft to dodge gunfire.
The evidence we have heard from military officers, with experience of A.A. gunnery in France, points to a gun rather larger than 3-in. calibre being the most suitable, because, not too heavy for rapid fire and rapid handling, with, at the same time, a heavier shell than the existing 3-in. The latter should not be adopted merely because it is already in existence. A.A. gunnery, generally is in too early a stage of development to warrant any gun being accepted without competitive trials with others.
76. Number of A.A. Guns. – We recommend that the number of these guns carried should not be less than four (six preferred), and there should be no blind arc in any direction. We see no objection to some of these guns being mounted on top of the secondary armament turrets, if this is practicable the arrangement would ensure a good arc of fire and save deck space.
77. Machine Guns or Pom-poms are required in sufficient numbers to make it quite certain that a low-flying airplane will be engaged by at least three, no matter how she approaches. A light gun has many advantages in handling, but it loses in stopping power, and against large and possibly protected machines may not be effective.
As with the larger A.A. gun, we recommend that the question be reconsidered without regard to what we have now or have had to use in the past.
STAR SHELL GUNS
78. Use of Star Shell. – Naval opinion is unanimous in favour of star shell for night encounters.
Their purpose is to search water where something has been seen to arouse suspicion, for which they the following advantages over searchlights:-
Their range is much greater.
Area of illumination is much larger.
They do not leave behind a point of aim for the enemy to fire at.
They are efficient in wet weather.
79. Shell capable of Improvement. – The evidence heard appears to show that we have not yet obtained a shell as good as the Germans used off the coast of Flanders, which, we understand, were of about 6-in. calibre and were fired from howitzers.
80. Howitzers should be considered. – The use of howitzers for firing star shell from heavy ships is recommended for consideration as being preferable to employing guns of the secondary armament, which, when star shell are being fired, should be ready to engage an enemy. It is uneconomical to use them for an auxiliary purpose. Disadvantages of howitzers are increased weight, extra space occupied, additional ammunition supply arrangements (as star shell guns may be required to fire a long series of rounds). There appears to be no objection to these howitzers being muzzle-loading to save complication.
81. Recommendation. – We recommend therefore that the proposal to employ howitzers for firing star shell be investigated and considered in conjunction with the designs of new ships.
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SEARCHLIGHTS.
82. Use of Searchlights. – Opinions on searchlights vary greatly both as to the number which should be mounted and as to when to employ them.
We consider that searchlights are necessary under circumstances when a target must be continuously illuminated to enable the gun armament to fire with maximum effect. Star-shell illumination is neither so brilliant nor so continuous, and therefore they cannot take the place of searchlights for close actions. The dazzling effect of a searchlight on attacking craft is another advantage.
83. Improvements after Battle of Jutland. – Before the war our searchlights were very inefficient; their method of control was so poor that no reliance could be placed either on their illuminating the target intended or remaining on it if picked up. This unsatisfactory state of affairs came to a head after the Battle of Jutland when the Commander-in-Chief, Grand Fleet, appointed a Committee to go into the whole question. As a result of recommendations by this Committee, improved projectors with elaborate and well-thought-out systems of control were designed and supplied. At about the same time, strong representations were made from the Grand Fleet for the supply of Star shell, which had been effectively used by the Germans both as an alternative to searchlights and as an additional aid to night operations. During 1917-18 trials with these shell were carried out by the Fleet and supply became general.
84. Number of Projectors. – The Grand Fleet Committee, previously referred to, laid it down that the number of projectors to be carried by a Capital Ship should be eight, and by a light cruiser four. The number eight was decided upon in order that a ship might engage two targets simultaneously on each side and have a spare light for each target, or, keeping only one as a spare, retain one light each side in reserve in case another target required to be illuminated. This undoubtedly fully provided for the most severe conditions which a ship could be expected to deal with theoretically; in practice, however, in our opinion, it is out of the question to expect so much and we contend that one target on each side is as many as can be engaged with any certainty of success. The principal reason for this is that the comparatively few opportunities which can be given to practice night firing, combined with the necessary three-watch system of manning the secondary armament at night, render it essential to keep the organisation as simple as possible. We consider that this justifies some decrease in the number of projectors now approved for Capital Ships.
85. Recommendation. – We consider that a Capital Ship requires four projectors, and that these should be mounted, two on a funnel, and two in th region of the main mast. Those on the funnel should be placed so as to bear as far forward and aft as practicable, especially forward, and therefore they should be “one-side” lights.
It would be an advantage were the two after projectors to be on the centre line so as to be available on either side, but this is a detail which is not pressed as there may be more important considerations in connection with their control.
We have not recommended an additional projector for use ahead as we think this unnecessary in a Capital Ship; the signalling projectors are quite sufficient for navigational and suchlike purposes. On this point we differ from the Fire Control Requirements Committee.
86. Control of Searchlights. – As regards the control of searchlights, we are of opinion that the primary control position should be on the Captain’s bridge; the best look-out is always kept on the bridge, the bridge Officers are always best informed as to what is going on. If not the Captain, then the Senior Officer awake will be on the bridge in charge of the ship.
TORPEDO ARMAMENT.
87. Advantages and Disadvantages of the Torpedo as a Weapon for Capital Ships. – Most divergent views are held on torpedo armament of Capital Ships and the question therefore needs examination.
The chief advantages possessed by the torpedo are its delivery of a very heavy blow under water, where ships are most vulnerable, and its invisibility of discharge and approach until comparatively close to the target.
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Its disadvantages are due to low speed and consequent long time of flight at normal action ranges, and the impossibility of correcting fire by observation of results. Torpedoes are also liable to gyro failures and cold runs which may endanger friendly ships. These disadvantages not only greatly limit opportunities for use but also reduce chances of hitting, because, if the target ships alter course during the run of the torpedo, it may not cross their track.
88. Torpedo Fire during the War. – As a weapon for big ships, the torpedo has accomplished very little during the war; our Capital Ships would not have been handicapped had they carried no torpedoes.
89. Moral Effect of Torpedoes. – The moral effect of torpedoes is undeniably very great. Because a torpedo may damage a ship so effectually that she has to break off action, even if she is not disabled or sunk, the threat of torpedo hits has a real influence on tactics. A Battle Fleet known to carry no torpedoes would be at a moral, and might be at a tactical disadvantage against one that had them.
90. Opinion. – Irrespective of the moral importance of the torpedo as a battleship weapon, we consider that ti has great value as a reserve of offensive power for use in darkness or thick weather when ships may meet at close range.
91. Recommendation. – We recommend that battleships should be armed wit one submerged tube each side in separate compartments, preferable aft where the mine danger is probably less than forward.
The torpedo armament and equipment should be arranged so that the ship incurs a minimum of danger from the position of the discharges and the weight of armour needed for its protection is as small as possible.
Control and wiring arrangements (see also paras. 104 to 106 under “Torpedo Controls”) should be simple; there should be no question of rivalling the gun. A torpedo control tower is not considered necessary.
The number of torpedoes per tube available for firing in action should be at least si, but complications to enable torpedoes to be turned round and fired from either side are not needed.
GUNNERY AND TORPEDO CONTROL POSITIONS
Main Armament Controls.
92. Positions now provided. – By gradual development we have arrived at what may be described as a standard arrangement of gunnery control positions (other than those in turrets) for the main armament, namely:-
Spotting top and light director tower aloft.
Armoured gun control tower and director tower as part of the conning tower structure.
.93. Fire Control Requirements Committee Proposals. – It has now been proposed by the Fire Control Requirements Committee that:-
(a) Instead of the above, a splinter proof combined spotting and director tower should be placed at a sufficient height to be clear of blast and smoke; a position on top of the bridge structure and not on the mast is proposed.
(b) A similar tower to be mounted aft where it will be below the funnel smoke but not in a turret.
(c) A fire distribution tower for the Principal Control Officer in easy access of the bridge.
94. Advantages and Disadvantages. – These proposals undoubtedly have advantages in that the gunnery positions forward are compressed into a more compact form, while, at the same time, a fully-equipped alternative position aft is arranged for. On t he other hand, it is disputable whether the arrangement provides such efficient fire control facilities as does our existing one.
95. Model to be made. – We understand that a model is to be made of the arrangement at Portsmouth before any further decisions are taken, and, as this will not be ready before we submit our report, we wish only to give it as our opinion that we should be unwise to give up the aloft position for either the primary control or the director without first thoroughly testing the new arrangement.
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96. Alternative Position. – For an alternative control and director, we do not think it much matters whether they are placed forward or aft, although there are advantages in being forward clear of smoke and the view is better.
97. Fire Distribution Tower. – We do not consider that a fire distribution tower is needed; it is only a sort of extra transmitting station. If, therefore, the alternative director and control position are placed aft, we would not provide any gunnery distribution tower forward so far as main armament requirements are concerned.
98. Other Control Positions. – We agree with the Fire Control Requirements Committee as regards the abolition of directing gun positions and of turret control positions of all descriptions, local control excluded. We think these are not only unnecessary, but extremely undesirable, as adding to complication and focussing attention on alternatives which it is most improbably will ever be used and if they are, will be of little value.
99. Local Control. – Means to control a turret locally are necessary because, without them, a ship might have her whole armament intact and yet be unable to fight it. Some form of local director is recommended, the arrangements being otherwise as simple as practicable. In any case, we strongly recommend that gunlayers’ and trainers’ sights should continue to be fitted.
Secondary Armament Controls.
100. Principal Positions. – We are in favour of keeping all secondary armament controls and directors off the tripod. It is unnecessary to give them either the command or the all-round view required for the main armament.
We are also in favour of greater simplification in arrangements, and would effect this by combining the spotting or control position with the director and fitting a small transmitting station immediately beneath and adjoining the director. The present plan of placing the secondary armament towers close to the Captain’s bridge is an admirable one, as it makes it so easy to communicate with them both by day and night.
The above agrees with the recommendations of the Fire Control Requirements Committee, except as regards the transmitting stations, which the Fire Control Requirements Committee propose to place in secondary armament towers in the bridge and conning tower support.
101. Alternative Positions. – An alternative control position each side is needed in case the forward directors are put out of action. The Fire Control Requirements Committee recommend duplication of the director positions low down aft; we do not consider duplication of the directors essential, provided that the forward directors are placed so that they bear within a few degrees of right aft and that an alternative control position can be arranged in one of the secondary armament turrets. The chief aim should be the greatest simplicity compatible with an efficient alternative.
102. Local Control. – Each of the secondary armament turrets should be capable of being controlled locally, arrangements being quite simple.
Anti-Aircraft Armament Controls.
103. We are unable to submit proposals in respect to these owing to their complicated nature and to lack of information and experience. The question is still under consideration by the Anti-Aircraft Gunnery Committee.
We consider that A.A. Control is a most important matter and that ships should be equipped with efficient installations as soon as these can be decided upon. We presume the director system will form part of it and are strongly of opinion that it should do so.
The A.A. armament is a necessity to modern ships in order to beat off aircraft before they can deliver their attack; planes are so hard to see and gunnery against them is so difficult at long ranges that it appears essential at present to concentrate effort on obtaining the best possible results at medium and close ranges.
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Torpedo Controls.
104. Primary Position. – The torpedo firing officer should be close to the Captain, and consequently the necessary instruments should be placed on the manoeuvring platform; this meets both day and night requirements. The instruments should be kept as few and as simple as possible.
A rangefinder should be allocated entirely to torpedo control; this would be best mounted in easy reach of the manoeuvring platform, but, if space will not admit, then one should be mounted each side in the most convenient position to obtain large arc and to be clear of blast.
105. Alternative Position. – An alternative position should be provided in the conning tower (see para. 111).
106. We do not consider that anything more than the above is needed and do not recommend a torpedo transmitting station.
We differ, therefore, from the Fire Control Requirements Committee on this question.
CONNING TOWER.
(See also para. 159.)
107. Bridge preferred to Conning Tower as Primary Position for Action. – At the present time, the majority of Flag Officers and Captains are of opinion that they would remain on the bridge in action on account of:-
The superior view obtained for handling the squadron or ship.
The torpedo menace; because, in order to have a good chance of avoiding torpedoes, their tracks must be seen in good time, which is not possible from the conning tower where the look-out is not only restricted, but is also interrupted whenever the main armament fires.
Better facilities for reading and sending signals.
Better able to judge the accuracy of the enemy’s fire and its effect on the squadron or ship; it may be desirable to alter course to dodge it.
108. Conning Tower necessary as Alternative. – Our evidence shows, however, that very few officers are willing to give up the conning tower, as it is necessary to have an alternative position which will not be put out of action by splinters or medium calibre shell hits.
We recommend that a conning tower should be retained in Capital Ships.
109. Position. – We have no criticism to make on the position of the conning tower in modern ships, the higher it is and the less it is built around and over the better the view and the less chance of its being affected by shell hits near it.
110. Size. – For a private ship, the conning tower need be no larger than is necessary to hold the Captain, Navigating Officer, Signal Officer, Torpedo Officer and three others, without overcrowding.
As any ship may be required to hoist a flag, space should be sufficient for the Admiral and one Staff Officer in addition to the above; it is not proposed to allow for a larger staff because the position is an alternative one, not the primary.
111. Fittings. – For convenience in conning, the tower should contain a steering wheel and should be the usual place from which the ship is steered. When the Captain goes to the conning tower, the ship should be steered from the lower conning tower. Engine room and revolution telegraphs should be worked from the same position as the wheel in use.
The torpedo control instruments and communications should be few and simple.
Communications and instruments of all descriptions and for all purposes should be reduced to the minimum necessary to enable the Captain to direct from the conning tower. The following are necessary:-
Gyro-compass receiver.
Helm indicator.
Engine room and revolution telegraphs (for use when ship is being steered from C.T.).
Range receiver to show main armament range.
Evershed bearing transmitter for main armament.
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Voice-pipes to - Manoeuvring Platform.
Signal Deck.
Manoeuvring W/T Office.
Gunnery Control Position, forward.
Lower Conning Tower.
Flooding Control Cabinet (if fitted).
Secondary Armament Control Towers.
Telephones to - Exchange.
Engine Room.
Steering Compartment.
W/T Decoding Room.
Gunnery Control Position, aft (if fitted).
PROTECTION.
112. Objects of Protection. – the chief object of protecting a ship is the perfectly obvious one of keeping her afloat, everything else should be subordinated to that because, if she sinks, the whole purpose of her existence is defeated. To keep a ship afloat it is necessary to protect her from all the sources of danger which might sink her.
The second object of protection is to safeguard motive and manoeuvring power so that, so long as a ship remains afloat, she can steam and steer. If she cannot do this, she becomes useless as a ship for the time being, irrespective of whether she eventually reaches harbour or not.
The third object of protection is to protect the armament and personnel so that the ship may remain in action even though she be heavily hit about her decks and upper works.
In our opinion the above must be the governing factors; there will always exist strong reasons why special protection should be afforded to various parts of a ship but the measure of protection allowed must be proportional, so that the vitals do not suffer in consequence and that the size of a ship as a whole can be kept within reasonable bounds.
Protection Necessary to Keep Ship Afloat.
113. Subdivision of Hull. – Sinking may be due to damage caused by any of the following:- Torpedo, mine, shell hits in the region of water-line, collision or grounding. As these forms of injury may occur at any point of a ship’s length, watertight subdivision within the hull is the first and surest means of saving a ship from sinking.
114. Points to be considered. – The following require to be taken into consideration:-
The size of each of the larger compartments and the effect of flooding them.
Where two of the larger compartments adjoin, the effect of flooding both.
Uniformity in size of compartments other than the larger ones referred to above.
The extent to which W/T subdivision may be sacrificed to convenience and accessibility in machinery spaces, boiler rooms, etc
115. Comparison between British and German Practice. – Generally speaking, it is considered that, although our latest ships are well subdivided below the armoured deck in so far as the average size of compartments is concerned, the result as a whole is spoilt by the existence of a number of very large and very small compartments. Comparison of the watertight subdivision of “Royal Sovereign” and “Baden” shows this clearly; while “Royal Sovereign” has the greater number of compartments (486 to “Baden’s” 425), her big compartments are more numerous and much larger. For example, “Royal Sovereign’s” main machinery compartments average three times the size of “ Baden’s.”
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116. German battleship subdivision differs from ours in three chief respects:-
The propelling machinery is of a three-shaft design instead of four.
The sections between transverse bulkheads, which contain propelling machinery and boilers, are divided into thirds by means of longitudinal bulkheads, each set of machinery being separate from the others.
The wing compartments abreast engine and boiler rooms are arranged and fitted for rapid flooding for correction of heel.
It seems probably that the three-shaft design is directly attributable to German views on subdivision and protection, as beam would not permit of subdivision into fourths for four sets of engines and at the same time allow a sufficient distance between the outer engine room bulkheads and the hull for torpedo protection.
117. British design aims at maintenance of stability without resort to flooding, consequently some of the largest compartments extend across the ship and the means provided for correcting heel are only sufficient to deal with the smaller ones and then slowly; nor are the means to flood arranged on any simple or uniform plan as part of a system as in the German ships. Generally speaking, it may be said that in our Service, Naval opinion, supported by Admiralty statements, has been against flooding to correct heel if it can be avoided. In view of the size of the larger compartments and the loss of buoyancy caused by flooding them, this is perfectly logical.
As opposed to our practice, the Germans evidently design on the principle that damage spreads and therefore must be confined within the smallest compass; their anti-torpedo protection and interior subdivision fully confirm this view. They could justly claim that, although their ships would heel when damaged, heel is quickly remediable, and that the total quantity of water admitted to the ship involuntarily and voluntarily is less that under any other system. Loss of buoyancy is therefore also less.
118. The main difference between the British and German design centres, therefore round preservation of buoyancy.
Both are alike in so far that the aim at keeping the ship upright, although the methods of accomplishing this are different, in that ours operates automatically and the Germans’ is dependent on the facilities provided and the organisation for working them. If flooding was always confined to large compartments extending across the ship, we might be able to dispense with arrangements to correct heel but, as this cannot be so, the German system is better able to cope with any contingency than is ours. To put it plainly, the heel and trim of their ships are better under control.
119. Advantages of German System. – The German system appears to us to have the advantage as regards buoyancy, stability and better control of the ship, the latter being of great importance both to gun platform and protection. The great number of longitudinal bulkheads must also add to the strength of the ship, besides reducing probability of a transverse bulkhead being exposed to water pressure along its whole width.
120. Subdivision of Turbine Rooms. – “ Baden’s” propelling machinery is cramped and inaccessible, due to the small size of the compartments in which it is installed. We consider that, in her case, insufficient importance has been attacked to facilities for efficient maintenance, which are essential for our ships.
We think, however, that with geared turbines an improved lay-out could be made and, allowing 17 ft. each side between outer engine room bulkhead and ship’s side, a width of at least 70 ft. should be available for the three machinery compartments on a beam of 106 ft.
In view of the great advantages to be gained by the closer subdivision, whilst again insisting on adequate room for maintenance, we recommend that a three-shaft design be adopted for our battleships.
So far as practicable, each set of machinery should be self-contained in its own third of the ship and there should be a W.T. bulkhead dividing each turbine set from its auxiliary machinery. Consequently, there would be, in all, six watertight compartments for the propelling machinery.
121. Subdivision of Boiler Rooms. – We find that there is no engineering objection to greater boiler room subdivision in oil-fired boiler rooms, and recommend longitudinal subdivision of the main watertight sections containing the boilers into thirds.
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The advantages are not only those of better subdivision, but also of reduction in proportion of boiler power likely to be put out of action at any one time.
In order that maintenance facilities may again be adequate, rather more space must be allowed than with undivided compartments.
A larger number of higher ratings will be needed for supervision.
122. Comparative Trials Recommended. – Owing to the strong feeling in the Service that the design of our Capital Ships is not such that they can be relied upon to remain afloat or to be under control after damage by mine or torpedo, the Committee recommends that full trials be carried out with “ Baden” and one of the older ships mentioned in para. 8.
We consider this to be of the utmost importance for future ship design.
123. Closer Subdivision advantageous against Gas Attack. – Closer subdivision has the additional advantage of affording better protection against gas attack, should this be developed for naval purposes by means of gas shell and gas bombs. With large compartments, a larger proportion of a ship’s fighting or steaming power must necessarily be exposed to the action of a single projectile.
124. Protective Bulkheads. – On account of the far-reaching effects of high explosives, especially under water, watertight subdivision by itself is insufficient and it is necessary to employ protective bulkheads to prevent serious injury spreading to compartments containing vital portions of the ship’s equipment, such as engine and boiler rooms and magazines.
This was part of the design of our modern Capital Ships before the war, but it was not so extensively employed as in some foreign navies. War experience has shown that our ships were not sufficiently protected against under-water damage.
We recommend a bulkhead of the strongest steel, not less than 2-in. thick, placed not less than 13 ft. from the ship’s side. The outer bulkhead of compartments containing machinery, boilers and ammunition should be not less than 17 ft. from the side. On a beam of 106 ft., this allows 70 to 72 ft. for the spaces containing propelling machinery and boilers.
125. Bulge Protection. – During the war, the bulge or blister was introduced as a comparatively simple means f quickly affording increased under-water protection to ships, because, being an excrescence, it could be built on to the hull without necessitating reconstruction of the interior of the ship. Further, it possessed a capacity, proved by trials, to effect what internal armour will not. The reasons are that, firstly, the bulge ensures that the full force of the explosion takes place at some distance from the hull proper, and the chief damage is therefore confined to the bulge compartments which in no way affect the working of the ship. Secondly, the form and construction of the bulge permits of an explosion being vented into the atmosphere outside the hull of the ship, which has proved to be of great importance as a means of diminishing destructive effect. The bulges when intact add to a ship’s stability, and, owing to their being filled with air-tight tubes to give cushioning effect, the amount of water entering after they are opened to the sea is small; thus the consequent heel is small.
126. By itself, however, the bulge is not sufficient to keep the effects of explosion of a modern torpedo outside the hull proper and, therefore, a protected (torpedo) bulkhead within the hull continues to be necessary; the more so in view of the probability of an increase in the power of torpedoes.
127. The bulge being an excrescence to the hull is distinctly clumsy. It provides no facilities for correction of heel, which we consider to be an essential feature in a modern Capital Ship. We do not know how the bulge will stand shell hits; its join with the ship’s side close to the water-line appears to be a weak place as its plating may be severely injured and thus the damage may spread and steaming and steering powers be interfered with. Trials are needed to test this with th target ship under way at hight speed.
128. Lastly, there is the question of whether bulged ships are as good gun platforms, as economical steamers and as handy as unbulged and, if not, whether the difference is sufficient to influence future design.
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129. Trials necessary. – We recommend that, before it is finally decided what system is to be adopted for the under-water protection of new ships, exhaustive trials be carried out between the bulge and the best alternative schemes that can be devised.
We suggest, for one, a scheme embodying cushioning tubes and vents to the atmosphere within the hull instead of outside it, in conjunction with facilities such as exist in “ Baden” for rapidly correcting heel.
130. Amount of damage which Ship should be able to receive without dangerous loss of Stability and Buoyancy. – We consider that six torpedo hits on one side should not result in such loss of stability that it cannot be rectified without reducing buoyancy beyond the lowest limit for safety.
131. Strength of Main Transverse Bulkheads. – In large compartments, especially forward, the main transverse bulkheads below the principal armoured deck should be designed to have a good margin of safety over and above that allowed to render them safe from compartments being flooded. A ship mined or torpedoed has to get back to base and there may be no choice between steaming at good speed and great risk of loss by further attacks.
It has to be remembered that a ship may be steaming fast at the moment of injury; unless bulkheads are very strong, immediate reduction in speed may be imperative to avoid their collapse before anything can be done to reinforce them by shores.
The strength of the main watertight section of a ship is also of great importance as a means of limiting the area affected by damage.
During the war, probably every British ship relied largely on shores to hold up damaged bulkheads, and it was even the practice to keep shores permanently rigged; the latter practice is undesirable because it affords a means of transmitting a blow to a bulkhead which might otherwise be unaffected.
Pumping and Flooding Arrangements.
132. Leakage consequent on Strained Bulkheads must be dealt with.- Owing to the large quantities of water that will flow through a hole of comparatively small size, it is not possible to cope with water entering through any considerable damage to the hull under water, and it must be accepted that badly injured compartments will be flooded, e.g., a hole 12 in. diameter, 16 ft. below the water-line, will admit 2,570 tons per hour.
While protective bulkheads should be sufficient to prevent serious injury spreading to vital compartments, it cannot be expected that they will be altogether unaffected or remain watertight if strained. In other parts of the ship of weaker construction, damage will be more widespread and bulkheads some distance away from the explosion will be affected. Water will find its way through strained bulkheads at a rate depending on the damage and, unless pumping arrangements are adequate, the number of flooded compartments is certain to increase, due to this consequential leakage.
133. Alternative Systems of Pumping. – There are two methods by which consequential leakage may be dealt with:-
- (i) By means of a main drain extending fore and aft the ship with sluice valves at the principal thwartship bulkheads and branches with shut-off valves to the various compartments. It can either drain into the engine room bilges, the water being then pumped out of the main circulators, or it can be connected direct to the circulator bilge suctions.
Note.- As originally fitted, the main drain was placed in the double bottom, where it was liable to facture in case of damage to the outer skin, as in the case of the “Howe” at Ferrol, but in later ships it was fitted above the inner bottom.
- (ii) By making each section of the ship between the main thwartship bulkheads self-contained as regards its pumping-out arrangements.
The latter plan has been adopted for all our recent Capital Ships. In “ Baden” the Germans used a combination of the two.
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134. Disadvantages of Main Drain. – The main transverse bulkheads are pierced by a large pipe. The sluice valves fitted at the bulkheads are inside the pipe and, therefore, being out of sight are libel to get out of order without being detected. There is the possibility of their being jammed in the open position due to damage, or of being prevented from closing by some obstruction, thus allowing water to flow from the damaged to undamaged compartments.
The convenience and efficiency of the main drain system, when working at its best, is undoubtedly great, but these advantages are not considered to outweigh the disadvantage attendant on any system which is liable to make matters worse, experience has proved conclusively that safety lies in keeping bulkheads as clear as possible of pipes, especially low down in a ship. Consequently we do not recommend a main drain system.
135. Advantages of Sectional System. – The chief advantage of making each section of the ship self-contained is that it avoids piercing main bulkheads in the manner described above. Its disadvantage is that use cannot be made of the most powerful pumps in the ship and that a large number of smaller pumps are required.
When first adopted, the pumps fitted in each section were entirely inadequate, the 50-ton pumps being only sufficient to deal with drainage.
136. Comparison of Pumping Power of “Royal Sovereign” and “ Baden” shows that the Germans attached much greater importance than ourselves to pumping power outside the main machinery spaces.
In the main machinery spaces both ships are well provided with pumps.
In “Royal Sovereign,” out of a total pumping power of some 11,000 tons per hour, only 1,150 tons is available for all compartments outside the main machinery spaces (i.e., boiler and turbine rooms) and 200 of these are by means of portable submersible pumps. In “ Baden,” with an approximately similar total pumping power, about 4,500 tons per hour is available for these outside compartments, without taking into account the main circulating engines, which can be used to pump out compartments abaft the turbine rooms. Actually “ Baden” can employ pumps of 3,600 tons forward and 4,500 tons aft, as against 600 and 350 in “Royal Sovereign.”
In “Hood,” distribution of pumping power is better and nine pumps of 350 tons capacity each are fitted for pumping out the main W.T. sections before and abaft the turbine and boiler rooms, giving, with the portable and drainage pumps, a total capacity of 4,450 tons per hour for all spaces outside the main machinery compartments. This is a great deal less than arranged for in “Baden” (8,100), although “Hood’s” displacement is 42,000 tons against “ Baden’s” 28,000. As the size of the main water-tight section increases with the displacement of the ship, the pumping power ought to be increased proportionately.
137. Opinion. – We consider that the provision made for pumping out the main machinery compartments in “Hood” is very good.
For the compartments outside these spaces, we recommend a system on the lines of “Hood’s,” but with the capacity of the pumps in the various sections increased from 350 to 500 tons per hour.
We recommend, further, the fitting of visible sluice valves in readily accessible positions on the main transverse bulkheads as already done on “Hood’s” boiler room bulkheads. Valves having an area of about 80 sq. in. would be sufficiently large. They should constitute no danger because visible and accessible while enabling the pumps of another section to be used in emergency.
138. Direct- or gear-driven Submersible Pumps. – Experience is needed before it can be said definitely whether the section pumps should be of the submersible pattern as fitted in “Hood,” or whether it would be preferable to mount the pump motors on a platform below the armoured deck and drive the pump by gearing. (The steam pumps in “Hood’s” boiler rooms are arranged thus). The submersible pup has its advantages but may require a great deal of attention for maintenance, or, failing this, prove unreliable. If the submersible pumps have to be stripped down after each occasion of working, some other means of readily pumping out drainage water will be desirable.
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Correction of Heel.
139. Present arrangements inadequate. – The arrangements fitted to our ships for rectifying heel have hitherto been crude and inadequate and compare most unfavourably with those in “ Baden” and “Goeben.”
We do not think we could do better than adopt “ Baden’s” system in its entirety. Briefly this entails:-
Larger seacocks and larger vents.
Seacocks and flood valves worked by gearing brought up to local flooding stations in each main W.T. section of the ship.
Provision of sounding tubes at each local station.
A central “flooding control” station situated near the lower conning tower for the Officer-in-Charge.
Good communications between the central and local stations.
Full equipment of drawings and plans at the central station to show at a glance the effect of flooding on heel, trim, sinkage and stability.
140. Rate of Correction of Heel. – We understand that “ Baden’s” arrangements enable 5 deg. of heel to be corrected in 15 min., and we recommend this rate be adopted for our ships.
141. Valves to be operated locally. – It has been suggested that the valves for correcting heel should be arranged to work from the central station by means of telemotors or other system; this would add to complication, while the valves are not likely to be used often in the life of the ship, and it would be difficult to test the system frequently so as to ensure its being in order.
We recommend, therefore, that the hand wheels for the valves be fitted in easily accessible positions for local working, but not to deck plate terminations which are not suitable for gearing of this importance.
Protection against Above-water Attack.
142. Reasons for Change in Methods of Armour Protection. – Two directions of attack must be considered, namely, horizontal attack on the side in the vicinity of the water-line, and vertical or plunging attack on the decks. Hitherto, protection of the region of the water-line from horizontal attack may be said to have been the dominating factor in the disposition of armour, the obvious reason being that a shell hitting hereabouts is directly threatening a vital portion of the ship, but ti should be remembered that, prior to the war, ships were designed to fight at what are now considered to be short ranges and, therefore, protection from horizontal attack was the chief consideration. In the respect that gunfire must always be more formidable at short ranges than at long, this remains unchanged. The real change lies in the fact that guns and gunnery have improved faster than armour and methods of armour protection; for example, a new shell can be designed, proved and supplied at any time, whereas armour cannot be altered or added to extensively after a ship is completed unless she be laid up for a long period. In consequence of these improvements in gunnery, the problem of how best to protect the vitals has become much greater, because at long ranges the angle of descent of projectiles is so large that the narrow main belt forms only a small portion of the whole target offered by the ship and, due to her beam, shell which hit above the belt may still reach a vital compartment.
143. Horizontal Armour the most effective because of Deflecting Effect. – As weight makes it impracticable for a ship to carry large quantities or armour of sufficient thickness to stop shell, we recommend that the greatest possible use should be made of horizontal armour in order to obtain the maximum deflecting effect due to the angle at which a shell will strike it.
144. Vertical Side Armour. – Vertical side armour should be carried along the whole length of the water-line to protect the vitals, namely, magazines, engines and boiler rooms. At the water-line the distances from the side to magazine, machinery and boiler spaces are least, and damage inflicted immediately endangers a ship by flooding.
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145. Thickness of Side Armour. – The thickness of the side or belt armour should be the greatest practicable on the displacement. The minimum thickness must depend upon the range which the Staff consider future naval actions are likely to be decided and the penetration of the heaviest contemporary shell at that range. That it will have to be large will be seen from the figures given below showing the penetrative powers of modern shell. Although, unfortunately, the figures are not quite accurate (see para. 27), the afford the best indication we can give upon which to work; they probably err if anything in favour of the gun, and this seems the more probable in view of the success of our thick armour in keeping out German shell.
Penetration of K.D. Armour.
Gun. |
10,000 yds. |
15,000 yds. |
20,000 yds. |
25,000 yds. |
15-in. Mark I (as now mounted in H.M. Ships) |
17.7 in. at 7° |
14.1 in. at 13° |
11.5 in. at 21° |
9.6 in. at 31° |
15-in. 50 calibre |
22.5 in. at 5° |
18.9 in. at 9° |
16 in. at 14½° |
13 in. at 22° |
16-in. American |
23.4 in. at 5° |
19.6 in. at 9° |
16.4 in. at 14° |
13.3 in. at 21° |
16-in. new gun |
23.9 in. at 5° |
20.3 in. at 9° |
17.3 in. at 14½° |
14.3 in. at 21½° |
18-in. Mark I (“Furious” Guns). |
21.8 in. at 7° |
18.7 in. at 12½° |
15.1 in. at 19° |
13.8 in. at 27° |
18-in. new gun |
25.5 in. at 6° |
22.1 in. at 10° |
19 in. at 15° |
16 in. at 22½° |
NOTE. – Angles are angles of descent.
146. Width of Side Armour. – The width of the side armour, and its position with regard to the water-line, should depend on the wave profile when the ship is steaming at high speed. The bottom of the belt must be below the hollows of the wave profile and the top should be above the crests. Allowance must be made for reduction in draught as fuel is used and movement of the ship in a moderate sea.
Trials are needed to ascertain behaviour of shell which strike the water at angles too great to ricochet, and whether armour below the water can be tapered.
147. After Extremity of Side Armour. – Vertical armour should not be carried beyond the point where the side begins to slope away quickly at the after end of the ship; its weight can then be more usefully put into the armoured deck.
148. Transverse Armoured Bulkheads. – We consider that transverse armoured bulkheads are less valuable than side and deck armour.
149. Side Plating above the Belt. – This should be of sufficient thickness to set in action a delay action fuze of the heaviest shell, which is believed to be two inches for a 15-in. The object is to endeavour to burst as many shells as possible before they reach the armour deck or redoubts, or, if not to do this, to reduce the chances of a shell penetrating that armour by bursting it before it has time to get through.
It would be an advantage were this plating capable of keeping out shell from medium calibre guns, but we do not recommend increased thickness on this account because weight must be saved for essential protection.
150. Internal Protective Bulkheads. – We recommend that a 2-in. bulkhead be fitted each side of the ship above the armoured deck and in continuation of the torpedo bulkhead as far as the forecastle deck.
The chief object of these bulkheads is to prevent the interior of the ship being wrecked across its whole width by shell explosion. They will thus make it easier to keep the ship water-tight and gas-tight in case of severe damage. They will, in addition, add to the general protection of the ship.
151. Armoured Deck. – We recommend that the armoured deck be proof against the heaviest contemporary gunfire at ranges between 20,000 and 35,000 yds., the latter being taken as the extreme limit at which ships can see to fight one another. Owing to flatter trajectory at lesser ranges, this should give immunity at these also. Outside 35,000 yds., the probability of being hit is so small as to be negligible.
The armoured deck should commence at the top of the side armour and be carried across the ship either horizontally, or at a small slope downwards until near the centre line, then horizontal for the width of the funnel and ventilation casings, and
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rising again on the opposite side. The sloped deck should give the best protection because the deflecting effect will be improved on the downward slope, which will be the engaged side, and will not be seriously reduced on the upward slope. It is not very probable that a shell would reach the upward slope before bursting but, if it did, its effect would be away from and not towards the vitals.
152. Openings in Armoured Deck are necessary for ventilation trunks, funnels and trunks for conveyance of ammunition. Ventilation trunks and funnels are much easier to deal with than ammunition trunks, because there is no transport up and down them and the can, therefore, be protected from shell fire by means of gratings on the same level as the decks; moreover, a shell bursting on or over one of these openings cannot destroy the ship by blowing her up or do more than partially disable her machinery. An explosion in a magazine trunk is a much greater source of danger, because it endangers the magazine; this is dealt with in para. 154 under redoubt armour.
With the thicker deck now contemplated the type of grating must be correspondingly strengthened.
Protective gratings should also be fitted to these openings where they pass through weather deck and lower deck; reasons being, that the weather deck should have no weak places in it, and that, as a grating cannot keep out what a deck does, a second line of protection should be provided to prevent large fragments of debris reaching the machinery and boilers. Curtain plates to protect from smaller fragments and blast should be fitted in addition over steam pipes or important machinery situated under openings.
Three suggestions have been made to the Committee in connection with openings in decks which we recommend for consideration, namely:-
That escape trunks from hydraulic and dynamo rooms, etc., should be interrupted at the armoured deck so as to obtain better protection from flash and fragments of shell bursting in the upper part of the trunk;
That trials should be carried out to ascertain whether the size of funnel openings and air downtakes can be reduced;
That coffer dams should be fitted round engine room ventilation trunks on the main deck in preference to W.T. shutters (introduced on account of damage in “Warspite” at Jutland), the former being much less liable to be damaged than the latter and also being self-acting, which is important if lights are out and damage is extensive.
153. Deck Protection other than the Armoured Deck. – War experience has shown the great importance of thick decks as a means of bursting shell before they reach a vital part of the ship. In long range actions the weather decks offer the largest target and will, therefore, probably receive the most hits; also these decks will receive any hits made by bombs from aircraft, bombs being certain to increase in size.
It is recommended consequently that the weather decks should be as thick as weight considerations will allow; in the wake of the turrets thickness should be increased if practicable. For the same reason it is desirable that the deck below the weather deck, where it is not armoured deck, should be a strong one.
154. Turret Redoubt Armour must be thick for two reasons; it surrounds the opening sin the armoured deck leading to the main magazines and shell rooms, and it protects the main armament ammunition supply. A shell explosion inside a redoubt endangers the magazine and puts out of action a large proportion of a ship’s main offensive power
Redoubt armour exposed to normal attack and not covered by the decks and side should b of similar thickness to the main belt; over the remainder of its area, thickness should be reduced according to the extent redoubts are protected by other portions of the ship’s structure.
We wish to emphasis, further, that we consider the armour-piercing capabilities of modern shell are too great to enable safety to be secured by armour alone, and it must therefore be sought by improving flash proof-arrangements between trunk
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and magazine and by protecting the charges from the time they leave the magazine to the time they are loaded into the gun. The problem of finding solutions to these questions is at least as important as any other now before the Service.
155. Turret Gunhouse Armour. – The present practice is to armour the front with plates equal or nearly equal in thickness to the main belt; we recommend its continuance. The turret sides, which are rounded or sloped away, should be considerably less than the front, especially towards the rear. The back plates might be yet thinner than the sides. Turret roofs, which offer a large target, should be flat and protected with armour of sufficient thickness to keep out shell at 20,000 yds. and greater ranges (see para. 150). There is justification for employing relatively thicker armour on the roof than elsewhere because of the larger area and the fact that the flat roof will deflect a blow which even an 18-in front plate might not withstand. If a satisfactory alternative position can be round for the rangefinder, it should be taken off the roof where it is a source of danger to the whole turret; mounted low down in the gun-house, with its arms projecting through the sides, it would be well out of the way and would have a clear view past the chases of the guns at all elevations.
156. Protection of Secondary Armament.- This has already been dealt with under secondary armament; lightly protected turrets and armoured ammunition tubes are recommended.
157. Magazine Protection. – We understand it ahs been accepted in principle to place the main armament magazines below the shell rooms in new Capital Ships, the danger from mine explosion being considered less than from gunfire, provided that the bottom plating is thickened.
We recommend, however, that magazine and shell-room areas be given special protection by means of plating on their crowns; also, if so situated in the ship that they do not obtain the same protection from the torpedo bulkhead as midship compartments, extra protection should be arranged at sides also.
158. Water-jacketing Magazines. – The water-jacketing of magazines in dealt with in C.B. 1515(24), the Technical History and Index, paras. 58 to 61. We think that this method of safeguarding magazines is very promising and strongly recommend that no expense be spared to make it a practical success.
159. Conning Tower (see paras. 107 to 111). – We think that the whole conning tower structure in our latest ships is much too large and heavy.
We recommend that it should be a small rounded or oval erection, of similar size to the gun control tower, which should be placed above instead of abaft it as present.
On account of its lesser importance, we consider it unnecessary to armour the conning tower against normal hits of heavy shell, but it should be proof against shell striking at more than 30 deg. from the normal at main belt range (see para. 145). A thickness of more than 9 in. is not contemplated.
So far as weight of conning and gun control towers allows, we recommend that the thick supporting structure be dispensed with, armoured tubes being substituted. There should be one for navigational communications and one for armament.
160. Bridges. – The bridge position being the primary one for Flag Officers and Captains in action, better protection must be provided than has hitherto been the case.
We recommend splinter proof decks, sides, and bullet dodgers.
Good command is essential, in order that tracks of torpedoes approaching the ship may be seen in time to enable them to be avoided. This applies as much when cruising as in action. It is not sufficient to rely on reports from look-outs n other positions; the brain of the ship at sea is on the bridge, and should be, as far as possible, self-reliant. We recommend a height of eye of about 80 ft. from the waterline.
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161. Gun Control Towers. – For the primary gun control tower the armouring recommended for the conning tower should suffice; revolving portions, such as the director, may have to be lighter on account of training gear and support, but they should be proof against medium calibre shell and fragments of large shell.
On secondary gun control and torpedo control towers (if the latter are carried) splinter-proof armour should suffice, as they are small and rounded in form.
Vents
162. Efficient venting has shown itself in a number of cases to be more effectual than actual protection, both against under-water explosion and shell hits. Light cruisers, destroyers and other small craft proved extremely difficult to sink or disable, even when very severely damaged, and this we attribute to their light construction which permitted the force of explosion to vent itself into the atmosphere. For a battleship or battle cruiser, reasons of strength preclude the almost automatic venting as in a lightly-built ship and it is, therefore, necessary to include venting arrangements in the design (see para. 129). To a great extent this can be done by means of the hatchways and escape, light and ventilation trunks, but insufficient information is available and trials are therefore needed.
DISPLACEMENT
163. We have nothing to add to what has already been written in paras. 4 and 9.
SPECIAL FITTINGS AND EQUIPMENT.
These are dealt with in alphabetical order for convenience.
ACCOMMODATION.
164. Captain. – We consider that large cabins are necessary for the captain’s accommodation in Capital Ships, and do not recommend reduction from sizes now customary.
Reasons are:-
The captain of any big ship may be required to entertain on a large scale abroad; a high standard is expected from British Officers, and this necessitates good accommodation.\
The fore-cabin makes a good court-martial room, lecture room and midshipmen’s school place.
Very little would be gained by reducing accommodation at the after end of the ship.
165. Sea Cabins. – Flag Officers and Captains require a bridge cabin in addition to their usual harbour accommodation, but these need be no larger than requisite to contain a bunk, writing table and folding wash place. We do not consider that shelters in addition to sea cabins and chart houses are needed, but the cabins should be close to the bridge. A bridge W.C. is necessary but not a bathroom.
No other officers should have sea as well as harbour cabins.
166. The Signal Officer, whose work is forward, should be accommodated forward; other officers should preferably be aft.
In war, as it will be necessary for a larger number of officers to be at close call from the bridge, there should be one or more officers’ night shelters containing whatever number of bunks (in tiers) is necessary.
167. Other Cabins. – Cabins should be provided for all commission and warrant officers, as otherwise difficulties arise as to where they are to sleep and keep their clothes. The number of berths in a cabin need not be limited to two for junior officers.
We think that this could be arranged by making use of the large spaces frequently to be found in cabin flats.
Pantries for Chief of Staff and Flag Captains are unnecessary.
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168. Midshipmen. – Midshipmen’s accommodation needs more consideration than is usually given to it. They should be aft, away from the ship’s company, for washing, dressing and sleeping.
169. Ship’s Company. – Even before the war, with only peace complements on board, ships had barely sufficient accommodation for their crews. With war complements, nearly every ship was overcrowded. We recommend that, in new construction, more care be taken to select the most suitable parts of the ship for living spaces, and not to allow store rooms to encroach on them.
170. Reading and Recreation Rooms. – We do not attach such importance to the provision of reading rooms as to giving C.P.O.’s and P.O.’s good messes, and to arranging for a covered-in smoking place for the ship’s company. It is most desirable to differentiate as much as possible between P.O.’s and lower ratings as it improves their position, and is, therefore, good for discipline. No reading groom can accommodate very many men, but a small one is needed for school instruction.
The men’s smoking place should preferable be forward, inside the superstructure, quite clear of officer’s cabins.
171. Sick Bay. – We consider that there is a tendency to provide Sick Bays out of proportion to what is necessary, and thus to occupy space which would be better allotted to messes. If an epidemic breaks out, it is always necessary to rig emergency sick quarters. During the war, men who were seriously ill, or likely to be, were always landed or sent to a hospital ship, and we presume that hospital ships will be used just as much in the future.
172. Heads. In ships where the Heads are situated right forward the ventilation of the Heads, when the forecastle is battened down, is unsatisfactory, and the air of the forward mess decks becomes very polluted.
It would be preferable if the Heads could be placed where ventilation to the atmosphere can always be kept open.
173. When the Heads are right forward, the distance men who are accommodated or work aft have to go to reach them is a cause both of discomfort and waste of time. It is most desirable that urinals should be provided aft, also two night emergency W.C.’s.
We recommend that urinals should be provided near bath-rooms, provided that these can be drained overboard.
174. We recommend that C.P.O.’s and P.O.’s Heads should be well removed from the ship’s companies. It is not good for discipline that P.O.’s should have to join in the crush for accommodation that takes place in the Head lobbies.
AIRCRAFT.
175. Two Turrets to be Fitted with Platforms. – We recommend that two turrets be fitted with flying-off platforms, suitable for two-seater machines. A battleship or battle cruiser is not a good aircraft carrier, but we so no possibility otherwise of the Fleet being sure of having the large number of machines which it will undoubtedly require. Moreover, ti has advantages from the point of view of co-operation between the ship’s officers and the air personnel who work with them, and of each ship being independent of an aircraft carrier for the early period of action and for exercises.
We consider that there is a limit of size to the flying-off platform beyond which it would be most unwise to go, because of the difficulty of quickly rigging and unrigging. In fact, if aircraft considerations are allowed to weigh too much the ship will be handicapped as a fighting unit.
Each flying-off platform should be fitted with a light, portable hangar of angle-iron and water-proofed canvas, for use in harbour.
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ANCHORS.
176. Anchors should stow in beds recessed into the side, so as to remove the spray nuisance which they now invariably cause when steaming at high speeds. This affects fighting efficiency, as the spray interferes with gun sights and rangefinders, and also with the gun’s crews and ammunition of guns mounted in the open.
BOATS AND RAFTS.
177. Boats. – A full report on ships’ boats was made from the Grand Fleet last year, and, therefore, we submit no proposals as regards types to be carried.
In oil-burning ships, boats should either be oil-fired or motor-driven, so as to simplify fuel supply. (See also paras. 190 and 192.)
Picket boats should be equipped for mine-sweeping (See para. 207.)
178. Rafts. – The Carley float is generally considered to be satisfactory, but the net and bottom boards as reported as being dangerous in case of capsizing.
CAPSTAN ENGINE AND GEAR.
179. Position of Engine. – We recommend that the capstan engine should be higher up in the ship than now customary, in order to obviate the need for long leads of steam pipes through bulkheads below the waterline. This will also save weight in shafting. From the point of view of immunity from damage a position above the armoured deck is considered preferable, as it is less likely to be affected by under-water explosion; it will be accessible without having to open up compartments which should be kept closed at sea.
180. Electric Capstan. – We recommend further, that the steam capstan engine be replaced by an electric or electro-hydraulic when a reliable design is produced. Advantages would be:- No steam pipes; no heating of compartments by the engine; readiness at short notice.
181. Centre Line Capstan. – In order to save weight, space and complication of gearing, we consider that the forecastle centre line capstan can be abolished and recommend, in lieu, that the bower cable holders be fitted with drums for working hawsers.
DECK PLATES.
182. Deck plates are not a suitable termination for shafting operating important valves such as flooding. A very small depth of water on the deck of a compartment, which may be in darkness, is enough to make it difficult to find them. The shafting should be carried up well above the deck at the side of the bulkhead and operated by wheel or spanner.
ELECTRIC CABLES AND FITTINGS.
183. Electric Cables. – Cab tyre and flexible braided electric cables are a source of danger from fire as they throw off pieces of adhesive and flaming insulation; flexible braided cable will also burn downwards. Lead-cased cable is not easily set on fire, but the molten lead from overhead leads is liable to injure personnel.
Steel braided lead-cased cable and bronze-braided cable withstand fire best and are the least dangerous when set on fire; they are therefore more suitable for use in warships, and especially throughout turrets and in the main gangways of a ship.
184. Electric Fittings. – Many of these are heavy in proportion to size and we consider that reduction in weight should be practicable. Watertight fittings are overdone.
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ELECTRIC GENERATORS.
185. Up to the present the steam reciprocating dynamo has proved the most reliable form of electric generator. We consider, however ,that the turbo generator will shortly be equally satisfactory and, in view of its advantages in other respects, recommend for new construction that it be adopted for all dynamos other that the Diesel machines needed to maintain the normal electrical power required in harbour when steam is down.
FIRE MAIN.
186. We consider that the arrangement of the salt water fire main now fitted in ships is satisfactory.
It has been proved by action experience that:-
The steam fire and bilge pumps, in addition to the electric pumps, should be able to discharge into the fore and aft main.
Shut-off valves are needed at each main transverse bulkhead, at each point where a pump discharge joins the fore and aft main, at each point where a rising main leaves the fore and aft main, and at each deck through which a rising main passes.
FUELLING ARRANGEMENTS.
187. Rate of Fuelling. – We recommend that the oil fuel embarking arrangements of a Capital Ship should enable fuel to be embarked at a rate of 600b tons an hour.
188. Number of Connections. – In a battleship, two connections each side for oil fuel embarkation are necessary; in a battle cruiser there should be three on account of her greater length.
189. Fuelling with own Resources. – We have had evidence to show that ships are not fitted to enable them to fuel themselves from tank lighters, and that, if this becomes necessary in a ship having large freeboard and deep draught, makeshift arrangements have to be made giving such a low rate of embarkation as to be entirely inadequate for anything but emergency use. This is a serious deficiency as it means that ships cannot take full advantage of local oil supplies and must never be separated from tankers when time is of any consideration. We recommend that Capital Ships should be able to embark oil fuel at a rate of 300 tons an hour, using own resources only.
GALLEYS.
190. In oil-burning ships, cooking galleys should be oil-burning or electric in order to avoid having to carry coal for them.
In battleships, the Admiral’s or Captain’s galley s usually situated far away from the cabins; this in inconvenient and uneconomical as there are not enough servants to carry the meals aft and extra men have to be employed. With electric or oil-burning galleys, we see no objection to the galley being aft near the cabins.
GAS
191. In new ships consideration must be given to protection against gas attacks, both in the matter of subdivision of the ship and the provision of fans for clearing compartments quickly. Ens of voice-pipes should have gas-proof shutters or plugs.
HEATING
192. In oil-burning ships, electric radiators should replace coal stoves in cabins and messes.
HYDRAULIC PUMPS.
193. Hydraulic pumps are remarked upon in para. 34 of our report on the battleship.
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INFORMATION RESPECTING BUOYANCY AND STABILITY TO BE SUPPLIED
194. Hitherto little information has been supplied to ships on the subject of buoyancy, stability, effect of heel and trim, and their rectification. It is not enough for orders to be issued to ships to investigate these questions themselves; they need help from the constructors, who should be responsible that ships commissioning are fully equipped with all the necessary information and with the plans and drawings required to work the system installed.
INSTRUMENTS – MULTIPLICITY OF GUNNERY AND TORPEDO CONTROL
195. We consider that a tendency exists to overdo the number of different gunnery and torpedo control instruments, thus adding weight and complication and occupying personnel in erection who would be better employed on maintenance. New instruments must be devised from time to time in order to progress, but supply has not always been based on sufficient evidence of necessity. This is shown by the number of instruments which are found in ships and are never used.
As the question has been under consideration by the Fire Control Requirements Committee, it is alluded to chiefly on account of the great expense involved when even a small fitting is supplied to the whole Fleet.
MAGAZINE COOLING.
196. This question has been so fully reported upon during the war that we think it necessary only to emphasise the importance of installing machines and fans of ample power, lagging hot bulkheads and decks and of eliminating hot pockets.
MAGAZINE FLOODING.
197. Rate of Flooding. – The object of fitting flooding arrangements to magazines is to enable the contents to b drowned in case of fire.
If the fire is inside a magazine no flooding arrangements, however rapid, are likely to be of any use unless fire is discovered at once and is small enough to be extinguished by a hose or buckets of water.
In our opinion, therefore, flooding pipes need not be larger than necessary to fill completely a magazine within a short period, and we recommend that this be fixed at 15 minutes. In a steel-built ship it is improbable that a fire in another compartment could endanger a magazine before a good deal more than 15 minutes had elapsed.
198. Magazine Structure. – The above does not take into consideration the danger of fire from explosion of ammunition outside it; in this event, the safety of the magazine will depend upon whether its structure is strong enough to withstand the force of the explosion and the efficiency of the flash-proof fittings to entrance, scuttles and, in the last resort, of the cases containing the explosives.
199. Additions due to Action Experience. – After the Battle of Jutland, all Capital Ships had sprayers fitted to magazines additional to ordinary sea flooding, the water for the sprayers being supplied from the fire service. This was provided primarily as a means of drenching everything from the top of the magazine downwards, but also afford a ready method of increasing the rate of flooding.
200. Position of Magazine affects Method of Flooding. – If all magazines were well below the water-line, flooding and spraying could be effected entirely by means of pipes leading direct from the sea, but since in may ships some magazines have their crows but little below the water-line, considerable time would elapse before the upper charges were drowned.
Again, if ships had power always available, any desired rate of flooding could be met off the fire service, but this cannot be depended upon.
We consider it necessary to retain means of flooding direct from the sea.
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201. Recommendation. – We recommend that in the case of magazines having crowns 10 ft. or more below the water-line, all flooding and spraying should be carried out direct from the sea and that, where this distance is less, a branch from the fire service should be fitted in addition to direct flooding from the sea.
In every case the sea flooding pipes should also be the sprayers, being led in at the top. The pipes for power flooding should be quite separate from those for sea flooding, except that there should be a connection to enable it to act through the sprayer pipes when required.
The sprayers system should play over the magazine sides as well as the downwards in case the fire causing the danger is at one of the sides.
202. Other Safeguards. – In each magazine of a hydraulic-worked turret, there should be a hose connection off the hydraulic pressure system, in order that a good force of water may be available instantly in case of sudden emergency.
Irrespective of magazine flooding arrangements, there should be in every handing room and shell room a connection from the fire service so that a plentiful supply of water is at hand.
In the handing rooms, the fire service should be fitted also to act as a sprayer, which should be controlled by its own master valve operated in the handing room. (This is an addition to the usual hydraulic drenchers fitted to drown the charges in the cages.)
The water-jacketing of magazines is referred to in para. 158 and, if this develops into a practical success, magazine flooding and drenching arrangements can be considerably simplified.
MARKING FOR IDENTIFICATION PURPOSES.
203. Bulkheads. – Compartments below the main deck should have marked on each bulkhead what compartment is on its other side and what is above and below. It is difficult in a large ship to remember all these details, and such information is invaluable in case of damage. It has been generally carried out in the Gleet during the war, but we emphasise the necessity for completing it before the vessel leaves dockyard or contractor’s hands.
Simple part section line diagrams placed about the ship are also a great help to the personnel in learning the ship and should be supplied.
204. Ventilation Trunks and Pipes. – Ventilation trunks and pipes of all descriptions, including voice-pipes, should be plainly marked in stencil on each deck and between each main transverse bulkhead through which they pass. This is much preferable to colour marking, which is not remembered.
205. Valves. – Some system, such as the red disc system, should be adopted for indicating the number of watertight valves in a compartment. Complete lists of all such valves and their positions should be supplied to ships on commissioning.
MINESWEEP.
206. Paravanes. – By means of their paravanes, ships must be able to act as their own minesweepers when clear of the land.
207. Minesweep for Picket Boats. – Picket boats of big ships should continue to be equipped for use in case proper sweeping vessels are not available.
We recommend a sweep of the Oropesa type, which can be worked by each boat independently, and that this matter be taken up by the Mining School.
MODEL
208. We strongly recommend that a steel sectional model on the lines of the one found in “ Baden” should replace the rigging model now supplied. It would be most useful as a means of learning a ship and her arrangements; without it, the task of getting to know a ship thoroughly is almost insuperable for Officers and men whose daily work does not bring them into touch with watertight subdivision, pumping and flooding arrangements.
Our “rig” models are doubtless of a certain value, but the want of them would seldom be felt.
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RANGEFINDERS AND GYRO-COMPASS RECEIVERS IN FLAGSHIPS
209. In flagships a rangefinder should be provided on each side of the ship for the use of the Admiral. It is frequently inconvenient for him to sue the ship’s rangefinders as he is just as likely to need the range of one of our own ships as of an enemy’s. A 12-ft. instrument is recommended.
If these rangefinders are not on the Admiral’s bridge they should be placed so as to be clear of blast, means of communication must be provided, and the rangefinder mountings must be fitted with bearing racer.
210. A gyro-compass receiver with azimuth bearing plate, is also needed for the Admiral’s exclusive use on each side of the ship.
SIGNALLING.
211. We have no remarks to make on the subject of visual signalling equipment, as this has been so fully reported upon during the war.
Some signalling must be carried on from the bridge in action and the signalman stationed there should be protected by mattresses. We do not consider that between deck war signals stations are necessary; they cannot be well protected and at the same time be well placed, and are consequently probably no safer than the bridges. Signalmen not actually required on deck should be stationed below behind armour, where they can be called up if needed.
Alternative arrangements should be fitted to enable flags to be hoisted in case the bridge position is wrecked, but these should be intended more for use after than during action.
212. Fleet Flagships. – In ships fitted as Fleet Flagships signalling arrangements generally need to be on a more elaborate scale, and we recommend that their requirements be considered separately.
STEERING AND CONNING POSITIONS.
213. Steering. – In addition to the conning tower, lower conning tower and hand wheel position aft, a steering position (with gyro-compass receiver) should be fitted in one engine room close to the steering engine, with mechanical telegraph from the lower conning tower. This provides full safeguard in case of damage to telemotor gear.
214. Conning. – An alternative conning position should be arranged in the aloft control position.
STEERING GEAR.
215. A source of weakness lies in the long length of shafting between the steering engines at the after end of the engine room and the rudder heads, which may be put out of line or jammed by injury to the ship.
Steering engines erected on a bulkhead are liable to be affected if the bulkhead is strained. We recommend that, if retained in the engine rooms in new construction, they should be carried on a stiffer foundation, built from the bottom of the ship.
We recommend, however, thorough trials of other arrangements, such as the Hele-Shaw-Martineau electric hydraulic system, which require neither a long length of shafting nor of steam pipe for their operation.
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TRUNKS FOR ACCESS AND ESCAPE.
216. Following present practice in regard to compartments containing hand steering gear, dynamos and hydraulic engines, a trunk for access and escape should be fitted from each compartment in which is placed a powerful pump for dealing with leakage.
WATER, CLEARING OF, FROM SPACES ABOVE ARMOUR DECK.
217. At present drains are not always fitted to enable water to be drained away from flats and compartments between the armour deck and upper deck, especially at the ends of the ship; we consider these to be necessary, as otherwise there is no means, except baling, of clearing them of water, which may thus accumulate faster than it can be cleared away, eventually flooding over hatch and door coaming and affecting other compartments.
The watertight flaps at present used for drains are necessary.
WIRELESS TELEGRAPHY.
218. All instruments and offices, except the manoeuvring set, should be behind protection. The manoeuvring set should be near the bridge and should be enclosed in splinter-proof plating of the same thickness as the manoeuvring platform. We do not recommend this office being situated on one of the higher levels, as the structure is already so large and heavy that nothing which is unessential for working the ship or squadron should be added at the top. Pneumatic tubes, voice pipes, and direct vertical tubes for passing message forms should be sufficient.
WATERTIGHT DOORS, HATCHES AND VALVES.
219. Size. – Our present practice of keeping doors and hatches as small as practicable is obviously desirable.
220. Fittings should be Strong and Simple. – In order to be effective, hand water-tight fittings must be strong, simple and easily operated; otherwise they become source of danger due to the probability of their being improperly secured.
221. Doors. – The oval shaped dished door employed in our submarines (and apparently in German ships of all classes) is preferred to our rectangular type, and there appears no objection to its use for many ordinary watertight doors.
The clips to close and open a light door should be connected together by levers, so that all work together, and also can only be closed in the proper direction (i.e., from up to down, and so not jar off). An easily-worked automatic locking lever should be fitted to hold the door opening and closing lever in the locked position. On heavy doors clips might be damaged by the door swinging on to them, and one damaged clip might then prevent a door from closing; an automatic catch in necessary to hold the lever and clips in the open position, unless purposely closed after the door is to.
222. Armoured and Heavy Hatches. – Heavy hatches which are in daily use for traffic should be fitted with counter-balance gear, which, in order to be better protected, should be placed beneath the deck from which the hatch leads down.
223. Manhole Hatches. – These are a war product, and it is open to question whether they have not been fitted on too extensive a scale.
In large hatches they afford a means of communication and escape which can easily be opened and closed, whereas a large hatch is difficult to open, unless balanced, and may be impossible to close against pressure. They can also be utilised as vents. They are, however, unsuitable for any hatch whose size does not permit of the manhole clips clearing the hatch clips in all positions, as no reliance could then be placed on watertightness.
224. Valves. – Watertight valves should be fitted in all ventilation supply and exhaust trunks where they pass through the armoured deck, and at the upper deck when they do not extend to the superstructure.
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WEIGHT, SAVING OF.
225. Height between decks is often unnecessarily great, especially between upper and forecastle decks and in superstructures; weight would be saved and size of target decreased if this were reduced.
Dwarf bulkheads or expanded steel partitioning should be employed in preference to complete bulkheads wherever practicable; and both assist ventilation.
Numbers of small fittings, such as racks and stowage irons, which are usually provided and never used, or they are removed after commissioning in order to improve appearance of paint work.
WORKSHOPS.
226. The present practice of providing separate workshops for artificers of different departments is the best for efficiency, but we believe that there is unnecessary duplication of the larger lathes and machine tools.
King’s Regulations and Admiralty Instructions, Article 947, makes it quite clear that the engineers’ workshop is the main workshop for all mechanical repairs.
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