H.M.S. Hood Association-Battle Cruiser Hood: H.M.S. Hood Reference Materials - ADM 116/4351: Report on the Loss of H.M.S. Hood

- Page 61 -

MOST SECRET

Subject: BOARD OF ENQUIRY HELD TO INVESTIGATE THE TECHNICAL ASPECTS OF THE LOSS OF H.M.S. "HOOD"

From:

THE COMMANDER-IN-CHIEF, HOME FLEET

Date:

24^th June, 1941

No:

851/H.F.0490.

To:

THE SECRETARY OF THE ADMIRALTY

I would be glad of their Lordships' early comments on the conclusion reached by the Board who inquired into the technical aspect of the loss of H.M.S."HOOD" (Admiralty letter N.L. 9821/41 of 11^th June, 1941.

2. If the explosion did take place in the after magazines, it is very difficult to understand why no signs of it were observed anywhere near "X" and "Y" turrets. The crowns of these magazines are only 16 feet below the quarterdeck which is less than a quarter of the horizontal distance from the after 4" magazines to the mainmast.

3. The above water tubes on the other hand are immediately below the observed position of explosion. The warheads are in a closed compartment where any explosion would be well tamped and as this part of the ship's structure is highly stresses when steaming at 28 knots in a seaway, I understand the explosion of the quantity of T.N.T. contained in the four warheads on one side of the ship would be more than sufficient to rend the upper and main decks and open the centre engine room to the sea.

4. The characteristics of the flame and smoke seen by the observers may have given some indication of whether the explosion was of cordite or T.N.T.

(Signed)

Jack C Tovey

ADMIRAL

- Page 62 -

File cover (D51)

FROM WHOM:

Rear Admiral HTC Walker

Subject:

Rear Admiral HTC Walker appointed President of a Board to enquire into loss of H.M.S. "Hood"

Date:

24.8.41

Text within

Inform Captain, H.M.S. EXCELLENT, in the following sense:-

A/"Rear Admiral H.T.C. Walker, who has been appointed President of a Board to enquire into the loss of H.M.S. HOOD, requires expert advice on the appearance and other characteristics of explosions. He requests to be given the names and addresses of experts in the effects of propellants and high explosives./B

(2) The name of Commander R.F. Knight of H.M.S.EXCELLENT has been suggested with particular reference to his experience in respect of cordite explosions.

(3) In anticipation of your concurrence, Rear Admiral Walker is being requested to communicate direct with you. His address is Admiralty (Dorland House), Lower Regent Street, London, S.W.1."

2. Inform C.S.R.D. in a new N.C. paper as follows:-

A ---B of para 1 in full.

(2) It is requested that the names and addresses of those members of your staff who are able to give the expert evidence may be communicated to

D.N.O.

(b) Rear Admiral H.T.C.Walker,

Admiralty (Dorland House)

Lower Regent Street,

London, S.W.1.

(3) Rear Admiral Walker will communicate direct with you with regard to the attendance of the expert witnesses.

3. Inform S. of E., Shoeburyness, in a new N.O. paper as follows (copy to D.S. of E., Eskmeals):-

(2) The name of Commander R.F.P. Maton has been suggested as having had considerable experience of various types of explosions during his Service at Shoeburyness. In addition you may be able to suggest the names of other members of your staff, who would be able to provide the expert evidence required. It is requested that the names and addresses of those members of your staff who would be available to give evidence before Rear Admiral Walker's Board may be communicatied to

D.N.O.

(b) Rear Admiral H.T.C.Walker,

Admiralty (Dorland House)

Lower Regent Street,

London, S.W.1.

(3) Rear Admiral Walker will communicate direct with you with regard to the attendance of witnesses.

4. Copy of minute addresses to S. of E. to D. of A., Ministry of Supply, for information.

JGR/

28.8.41

(Signed)

Markham

For DIRECTOR OF NAVAL ORDNANCE

28^th August, 1941

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From: Rear Admiral H.T.C.Walker

Date: 24^th August, 1941

To: D.N.O., Admiralty, Bath.

I have been appointed President of a Board to enquire into the loss of H.M.S."HOOD" and instructed by Their Lordships to obtain expert advice on the appearance and other characteristics of explosions. I should be glad therefore, if you would give me the names and addresses of experts in the effect of propellents and high explosive and authorise me to communicate with them direct. Commander Knight (H.M.S. "Excellent") Commander Maton (late "Shoeburyness") amd C.S.R.D. have been suggested to me but of course they may not be your choices.

My address from a.m. Wednesday 27^th August will be Admiralty (Dorland House), Lower Regent Street, London S.W.1.

(Signed) H.T.C. Walker

Rear Admiral.

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DIRECTOR OF NAVAL ORDNANCE

Captain, H.M.S EXCELLENT.

H.M.Gunnery School,

Portsmouth.

28^th August,

Rear Admiral H.T.C.Walker, who has been appointed Predident of a Board to enquire into the loss of H.M.S. HOOD requires expert advice on the appearance and other characteristics of explosions. He has requiested to be given the names and addresses of experts in the effect of propellants and high explosives.

2. The name of Commander R.F. Knight of H.M.S. EXCELLENT has been suggested with particular reference to his experience in respect of Cordite explosions.

3. In anticipation of your concurrence, Rear Admiral Walker is being requested to communicate direct with you. His address is Admiralty (Dorland House), Lower Regent Street, London, S. W. 1.

JGR/

28.8.41

(Stamped)

F.R.PARHAM

For DIRECTOR OF NAVAL ORDINANCE.

- Page 65 -

CONFIDENTIAL

Rear Admiral H.T.C. Walker appointed
President of a Board to enquire into
Loss of H.M.S.HOOD.

C.S.R.D.

(G.012531/41)

2. It is requested that the names and addresses of those members of your staff who are able to give the expert evidence required may be communicated to

D.N.O.

(b) Rear Admiral H.T.C.Walker,

Admiralty (Dorland House)

Lower Regent Street,

London, S.W.1.

(3) Rear Admiral Walker will communicate direct with you with regard to the attendance of the expert witnesses.

JGR/

28.8.41

(Stamped)

F.R.PARHAM

For DIRECTOR OF NAVAL ORDNANCE.

28^th August, 1941.

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Bath

DIRECTOR OF NAVAL ORDINACE

Rear Admiral H.T.C.Walker,

Admiralty (Dorland House)

Lower Regent Street,

London, S.W.1.

28^th August

The best people I can suggest to give you the expert advice on the appearance and other characteristics of explosions are the ones you suggest.

Commander R.F. Knight, of EXCELLENT, has been concerned for some years with practical trials in connection with explosions of all kinds, chiefly cordite fires, and I can think of no one better to deal with this aspect. I have already mentioned verbally to Captain Packer that I have suggested that Knight should give evidence before your Board and he has agreed. Perhaps you will communicate either with him direct or Commander Knight; I am sure he will not mind you doing the latter.

Commander R.F.P. Maton, Proof Range, Eskmeals, Bootle, Cumberland is a member of the staff of the Superintendent of Experiments, Shoeburyness, who has been communicated with with (sic) a view to selecting somebody to give you the best technical advice. Perhaps it may be Commander Maton or somebody else. I am also communicating with C.S.R.D. who should be able to nominate someone who will give you the expert advice on the behaviour of all modern explosives. I presume that, to advise you on the effect on structures and so forth, you will be calling on D.N.C. to provide you with advice.

I hope that you will call on me to suggest any further people to clear up any particular point which may arise.

Copies of communications to Captain, H.M.S.EXCELLENT, C.S.R.D. and Superintendent of Experiments are enclosed for your information

For DIRECTOR OF NAVAL ORDNANCE

(End of file which started on page 62)

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(File cover D51)

G012949 1941

SECRET

FROM WHOM: Rear Admiral H.T.C. Walker

Date: 1-9-41

Subject: H.M.S. "Hood"

Requesting data re - total weight & weight of explosive of "Bismarck's" 15" shell. Angle of descent & remaining velocities at certain ranges etc.

The following information is forwarded:

Total weight of BISMARCK's 15" A.P.C. shell is approximately 1600lbs. The filling consists of 45.5lbs of TNT/Wax of which approximately 6.2lbs is wax, leaving 39.3lbs of explosive.
D.N.O. has no reliable information of the muzzle velocity obtained in German 15" guns or of the c.r.h. of the ballistic cap of the A.P.C. shell and therefore is unable to state with any confidence what ballistics are obtained. Solutions of resulting angles of descent and remaining velocities were recently worked out using the following data.
Weight of shell 1600lbs c.r.h.6 M.V.2721 f.s.
Weight of shell 1600lbs c.r.h.8 M.V.3150 f.s.

These data were used as representing the probable lower and upper limits of performance of the German 15" gun.

The M.V. of 2721 f.s. is the figure given in a report received from Russian Intelligence Resources but its reliability cannot be confirmed and other figures in the same report are known to be incorrect.

The M.V. of 3150 f.s. was based on a report in N.I.D. 0177/38 which indicated a muzzle velocity between 900-980 metres per sec. Other reports may have indicated the German preference for a high M.V. i.e. 28cm guns in DEUTSCHLAND are credited with a M.V. of 3150 f.s. D.N.O. considers that this figure for M.V. is unlikely to be greatly exceeded.

Data A and B give results as shown:-

Data A			Data B
Range	Remaining Velocity	Angle of Descent	Remaining Velocity	Angle of Descent
20,000	1718 f.s	14.5°	2070 f.s.	10°
18,000	1797 f.s	12.2°	2162 f.s.	8.5°
16,000	1884 f.s	10°	2259 f.s.	7°

Evidence with regard to fuze delay was given before the Committee by Captain Woollerton on 5.9.41.

JMC/

RCW

HKS

6/9/41

(signed)

PVM Laughlin

For DIRECTOR OF NAVAL ORDNANCE

6^th September, 1941

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REFERENCE SHEET

From:

Rear Admiral H.T.C. Walker,

Room 8, 5^th Floor,

Dorland House,

Regent Street,

S.W.1

Dated: 1^st September 1941

To:

DIRECTOR OF NAVAL ORDINACE

BATH

SECRET

Having been directed to enquire into the technical aspects of the loss of H.M.S.HOOD, it is requested that you will supply me with the following data:-

Total weight and weight of explosive of BISMARCK'S 15" shell
Angle of descent and remaining velocities at the following ranges: -
20,000 yards
18,000 yards
16,000 yards
An expression of opinion of the fuze delay likely to have been used against H.M.S. Hood.

An early reply would be appreciated.

(Signed)

H.T.C. Walker

REAR ADMIRAL

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(File cover D51)

G013269 1941

SECRET

FROM WHOM:

DIRECTOR OF NAVAL ORDNANCE

Date:

8^th September, 1941

Subject:

Metallurgical examination of the 15 inch A.P.C. shell ex BISMARCK.

Piercing Qualities.

(Minute within)

With reference to Captain Woollerton's evidence before the Committee on 5/9/41 it has been ascertained the C.S.R.D's metallurgical examination of the 15 inch A.P.C. shell ex BISMARCK has not yet proceeded sufficiently far for him to express an opinion on its piercing qualities in comparison to British shell.

D.N.O. has, however, no reason to suppose that any considerable difference in piercing properties exists between British and German shell.

FMA/

RCW

8/9/41.

(Signed)

PVM Laughlin

For DIRECTOR OF NAVAL ORDNANCE

8^th September, 1941.

(Further minute)

In accordance with instructions in Admiralty Letter N.L.9821/41 of 31^st July, eight copies of this report have been supplied. Copies have been sent to the First Lord, First Sea Lord, V.C.N.S. and Secretary and it [is] submitted that instructions may be given as to whether copies should be sent to D.N.C. or any other Admiralty Departments.

(Signature illegible)

for HEAD OF N.L.

12^th September, 1941.

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Minute sheet No. 1

This report and appendices are accepted as containing all that will ever be known of the circumstances attending the loss of HOOD and the probable cause. The Board of Enquiry has collected a wealth of data and a definite conclusion has been reached. But that part of the report headed 'Cause of the Ship's Destruction' shows clearly that the Members of the Board experienced difficulty in coming to such a conclusion.

2. D.N.C. fully appreciates the difficulty, as it appears established from the evidence that some part of the products of the magazine explosion vented an appreciable distance forward of the after magazines and although the after magazines blew up the ship broke her back in the region of the mainmast.

3. The safe course to take for future guidance is to assume that all the possible causes ₀f the ship's destruction did in fact arise.

4.The material lessons to be learned are considered to be the following:-

(a) Protection of magazines. This is an old story which unfortunately could not be thoroughly applied when HOOD was built. There is however, one phase of this which must be emphasised. It has always been considered that Q.F. magazines are safer than B.L., but just as much care must be taken to the protection of Q.F. and H.A. as to B.L. charges.

(t) Above-water torpedo tubes. These should not be between decks and should be situated where the detonation of the warhead will not seriously damage the main strength girder of the ship. It is understood that in cruisers the torpedo tubes are trained, outboard during a gun duel.

(c) Ready Use Ammunition. The fire on the boat deck, though not the cause of the fatal explosion was very severe. Previous experience has led to the belief that fire will not readily spread from one ready-use locker to another. This evidently happened in HOOD possibly because the U.P. ammunition on the deck below was burning, possibly because it was inevitable with such a H.A. armament and course of H.A. ammunition that a very large quantity of H.A. ammunition had to be in ready Use Lockers on the boat deck. It is considered that U.P. ammunition should not be kept between decks and that the quantity of ready use ammunition on the gun deck should be severely restricted.

5. Action has already been taken regarding 4(a). It is proposed that action be taken re 4(b) and 4 (c).

6. D.N.C. has received a copy of the report etc. for retention.

(Section 4)

(Signed)

SV Goodall

10/10/41

(Stamped)

D.N.C.

10 OCT 1941

(Manuscript note)

Office note

A reply would appear necessary to letter from C-in-C Home Fleet contained in N.L.11131/41 attached to this bundle.

(Further minute below)

After reading very carefully through all the evidence and the findings of the Board, it is quite clear that any expression of opinion regarding the possible detonation of warheads is entirely conjectural.

2. Further, the Board in their conclusions considered that even if one or two warheads had detonated, their effect would not have been so disastrous as to cause the immediate destruction of the ship and on the whole they are of the opinion that they did not detonate.

3. In view of the above, D.T.M. does not entirely concur with paragraph 4(b) of D.N.C's minute, but would qualify it to the extent that he agrees that it would be better to situate above water torpedo tubes on the upper deck rather than between decks, but this need not be applied to ships which already have between deck torpedo tubes, i.e."Repulse" and "Renown". And that this aspect be borne in mind should it be contemplated in the future to re-introduce torpedoes as part of the armament of capital ships.

(signed)

Illegible

D.T.M.

3^rd November, 1941

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Minute sheet No. 2

Detailed remarks by D.N.C. on the question of safety of B.L. magazines and recommendations as to the steps that should be taken to increase the security of magazines and their explosive content are being raised on a separate paper, in order not to delay the transit of this paper.

2. With reference to D.N.C's minute of 10.10.41:-

Para 1. Concur. It is of interest that both Boards of Enquiry virtually reached the same conclusion.

Para. 2 Concur

Para. 3 Concur

Para. 4 (a) While agreeing with D.N.C's remarks, D.N.O. would prefer to qualify the statement by saying "Q.F. magazines in which the whole charge is contained in a brass case", in order to avoid a false impression which is generally held that the German method of using a brass cartridge case for a portion of the charge in heavy guns makes their magazines much safer. Whereas in reality the front part of such a charge is not necessarily better protected that a B.L. charge.

It is presumed the words "and H.A." in the last line but one is intended to refer to Ammunition for other forms of Anti-Aircraft equipment since H.A. charges can be in the form of either B.L. or Q.F. cartridges.

Concur generally with D.N.C. See remarks on D.N.C's para. 5 below.

Para.5 re 4(c) The question as to the possibility of reducing Ready Use Stocks of H.A. Ammunition when in waters not liable to air attack is under consideration on T.S.D.805/41. D.N.O. considers that an early decision on this question is required.

On A.M. 5917/41 attention has been drawn to the quantities of explosives stores in unprotected positions above the water-line in Aircraft Carriers, the amount of which has now reached startling proportions. An early decision on this paper is also most desirable.

With regards to 7" Rocket Ammunition (A.A.D.Type B), it was approved on T.S.D.684/41 and promulgated in C.A.F.O.2163/41, that when Oerlikon equipments are mounted in ships at present mounting 7" Rocket Mark !(W) equipments, the latter are to be landed.

It is recommended that these 7" Rocket equipments and A.A.D. Type B. should now be landed at once where this has not already been done.

3. D.G.D. referred.

(Signed)

Illegible

DIRECTOR OF NAVAL ORDNANCE.

10 November, 1941.

BRC/

PAT

9.11.41

(Next Minute)

Concur generally with D.N.O., but it is considered that whereas a brass cylinder affords great protection against "flash", the really dangerous article is an ingnitered cartridge. A cartridge with no igniter (such as the "first" German charge or our own 8" and 6" non-ignitered charges) is relatively safe. If a shell detonates in the magazine itself a B.L. or a Q.F. charge will probably blow up with almost equal facility but, from a nearby explosion "flash", our present B.L. magazines are a really serious wekness in their vulnerability - due to exposed ignitered cartridges.

2. D.N.O's 2 para. 5 A.M.5918/41 will be pursued, and if it is agreed that all 7" rocket ammunition should be landed.

3. It has been decided on T.S.D.805/41 that reduction of stocks of R.U. ammunition should be left to the C.Os. of ships.

4. Submitted for approval to order all ships which still carry 7" rocket MarkI (W) equipments to land them at the first opportunity.

(Signed)

? Cook

G.T.C.

DIRECTOR OF GUNNERY & ANTI-AIRCRAFT WARFARE DIVISION.

14.11.41

(Manuscript)

Submitted for consideration

? Lawson

Head of N.L.

(Further minute)

In view of the importance of this matter, and also because the question has already formed the subject of discussion at the Board in connection with the vulnerability of modern Capital ships of British design as compared with those of German design, it may be thought desirable that whatever conclusion the Board come to upon the evidence and minutes now presented to them should be determined at a Board meeting and recorded in that form.

If the First Lord approves the inclusion of this subject in the Agenda for the next Board Meeting, I propose to circulate the minutes of the Members of the Board which will appear on this paper, together with so much of the report of the Board of Enquiry and other minutes on this paper as may be necessary for a final discussion at the Board.

- Page 75 -

When a Board decision has been given, I agree that it will be necessary to reply to the C. in C. Home Fleet as proposed in the Office Note on the back of Minute sheet 1 herein.

(Signed)

HVM

22^nd November, 1941

(Further Minute)

The conclusion of the Board of Enquiry is that the after 4" magazine probably exploded first, followed by the after 15" magazine, which is only natural as it was so near. As the charges in the 4-unch magazine were QF charges in brass cases it seems probable that the explosion was due to a direct hit in the magazine and not to a "flash" and so the only question at issue from this case to prevent a repetition is hot to protect the magazine from a direct hit.

2. From D.N.C's remarks on BISMARCK in other papers it seems that the magazines of modern German ships are no more better protected, and possibly not as well protected as the magazines of our newer ships. Our Capital ships suffer however from the serious effect of the vulnerability to "flash" of the ingitered B.L. cartridges. This has been overcome in 8" charges and smaller by doing away with the powder igniter and using a 1-inch tube for firing. This solution has not as yet proved practicable for charges of heavier guns, but is being discussed on other papers.

3. The German solution is a brass case.

4. I will defer further remarks until consideration of "X" above is complete.

(Note: Final two sentences above have been marked "X" in the margin)

(Signed)

R. McG

ACNS (W)

3^rd December, 1941

- Page 75 reverse -

Both Boards of Enquiry consider that the HOOD was lost due to a magazine explosion.

We cannot get away from the fact, therefore, that the magazines in our ships have blown up on several occasions in this war and in the last, whereas, as far as I know, there have been no cases of German ships blowing up although the BISMARCK and the LUTZOW (in 1916) were given a tremendous hammering by gunfire before the former had to be torpedoed by us and the LUTZOW by the Germans before they could be sunk.

If these reports by the two Boards of Enquiry are accepted, as I think they should be, then we want

To provide such protection to the magazines of our ships as will prevent enemy shells from penetrating them.
To provide ammunition that is not likely to be detonated.

We do not know for certain whether the primary cause of our losses has been due to lack of protection in the magazines or a weakness in our ammunition. I think, therefore, that we should take active steps as regards both (a) and (b) but if we could achieve (a) fully this would provide security even if our ammunition remains suspect.

I do not think we should allow D.N.C's remarks on other papers, that the magazines of German ships are no better protected than our newer ships, to deflect us from making our magazines safe from penetration if this is practicable.

(Manuscript addition)

What evidence have we as regards the comparative destructive powers of our shells and German shells.

(Signed)

HRM

VCNS

5^th December, 1941

(Manuscript notes beneath)

Noted

2. Magazine is good in our new ships, poor in older ships.

3. We have put in some additional armour in R class but it is not very satisfactory.

BAF

6/12/41

Controller

- Page 76 -

Minute sheet No: 4

I do not think that there is much doubt that the HOOD was lost as the result of the explosion of the after magazines and that no blame attaches to the Vice-Admiral Commanding the Squadron, the Captain or anyone else.

2. The two main points which have been brought out in these minutes concern magazine protection and detonation of ammunition.

3. It was known that HOOD's protection was poor by modern standards and had it not been for the war she would by now have been undergoing complete reconstruction.

4. This docket has been held up during my absence in Washington but, in the meantime, A.C.N.S.(W) has been going into the matter. I enclose a further minute from him, dated 22^nd January, describing the present situation.

5. The protection of magazines against direct hits has been investigated recently by D.N.C. in comparison between the BISMARCK and the K.G.V. and the result of his investigations is attached.

6. With regards to protection from flash, it is obvious that we cannot alter existing ships to brass obduration and it is, therefore, necessary to do all we can to make our ships as little liable as possible to blowing up of magazines.

7. The Secretary suggests that the report of the Board of Enquiry be brought before the Board and, if First Lord approves, I consider that at the same time the Board should have before them, and at an early date:

a report showing exactly what lessons were learnt from the destruction of HOOD;
what action has been taken on these lessons;
a report showing:
why presnet igniterless charges cannot be used in guns above 8";
in what manner the tinfoil covered igniters are likely to prevent a magazine going up;
what action is being taken to get an igniterless charge in guns above 8" and whether this matter is being treated as of transcending urgency.

8. In notice that D.N.C. in remarking on damage to BISMARCK is not surprised that she stood up to 5 torpedoes. This makes it all the more necessary to determine why PRINCE OF WALES suffered so severely from at most 2 torpedoes.

(Signed)

1^st February 1942

(Manuscript note below)

Concur with First Sea Lord's paras 7 and 8. Action accordingly.

AVA

4/2

(Further manuscript note below)

The necessary information in accordance with Par 7 of my minute is now enclosed.

Propose to bring before the Board as approved by First Lord and to circulate not less than 4 days before the Board meeting.

27/2

Concur with First Sea Lord.

AVA

1/3

- Page 77 -

Minutes sheet No: 5

Submitted.

The principal lesson of the loss of H.M.S. "HOOD" is that the magazines of a warship should be so situated and protected that, so far as can be foreseen, it is impossible for a shell or splinters of a shell to penetrate such a vital compartment. This is not a new lesson. It was learned during the last war and applied to the two capital ships designed after that war, the magazines being placed below the shell room and below very heavy deck armour of a new type developed for the purpose.

2. Since that date the necessity for such a change in design has been emphasised by the results of a long service of magazine trials and the development of aircraft carrying heavy bombs.

3. This lesson was applied as far as practicable when the older capital ships were reconstructed. It was intended to reconstruct "HOOD" in this way after "QUEEN ELIZABETH" was completed, but the outbreak of war prevented this. Except for "ROYAL OAK", nothing was done to the "ROYAL SOVEREIGN" class, as these ships were to be scrapped when the ships of the "KING GEORGE V" Class were completed. It was not possible in these old ships to place the magazine below the shell room.

4. The present situation in regard to the capacity of existing capital ships to withstand German 15" shell reaching the magazines is as follows:-

(a) Side Protection: Main Belt

At 90° Inclination	"KING GEORGE V" Class	Immune outside about 15,000 yards.
	"NELSON" and "RODNEY"

	"QUEEN ELIZABETH" Class	Immune outside about 18,000 yards.
	"ROYAL SOVEREIGN" Class

	"RENOWN"	Can be defeated at all ranges up to 28,000 yards

(b) Deck Protection

KING GEORGE V" Class	Immune inside about 34,000 yards
"NELSON" and "RODNEY"	Immune inside about 35,000 yards
"QUEEN ELIZABETH" Class	Immune inside about 27,000 yards

"ROYAL SOVEREIGN" Class	Vulnerable - see Para 5.
"RENOWN"	Immune inside about 24,000 yards

5. With reagrd to the "ROYAL SOVEREIGN" Class, it has been approved since the loss of "HOOD" to add 2" N.C. armour over the magazines as opportunity offers, this is the most that can be fitted without extensive reconstruction involving re-bulging. This addition only provides protection against 15" German shell inside 20,500 yards.

6. It appears likely that the German shell which caused the destruction of "HOOD" entered the ship at fine inclination and penetrated the protective deck forward of the area where deck protection had been added over the magazines during construction, it then travelled a considerable distance before bursting. The protection of all our capital ships has been carefully reviewed to ascertain if at fine inclination it would be possible for a shell with a long delay to dodge the main protection and burst near a magazine. As a result of this examination the following action has been approved:-

"NELSON"

Fit an armoured bulkhead forward from hold to platform deck. This will be completed during the present refit.

"RODNEY"

As "NELSON". Also fit as early as practicable the additional lower deck armour approved before the war and already fitted in "NELSON".

"QUEEN ELIZABETH" Class.

Fit an armoured bulkhead forward and increase the area of the umbrella over the magazines. This has been done in "WARSPITE", armour has been ordered for the remaining ships.

The above is shown on the enclosed drawing, D.N.C. 2/A.595.

7. Although not a lesson of the loss of "HOOD", it was a less on the same action that a German 15" diving shell might enter a ship below the armour belt and burst near the magazine. Although a German shell did enter "PRINCE OF WALES" in this manner, it was not in a condition to burst, and it is thought that if it had been in such a condition, the burst would have occurred before it reached the ship. Nevertheless, additional splinter protection to guard against such a possibility has been fitted in "DUKE OF YORK", "ANSON", and "HOWE", and is an approved A & A for "KING GEORGE V". Owing to the work and time involved, nothing can be done in this respect to the older capital ships unless they were taken in hand for expensive repairs - say requiring 12 months.

8. Action has been taken (a) to land U.P. mountings and ammunition, (b) to call to the attention of all ships to the need and to the desirability to guard against the dangers arising from ready-use ammunition in the upper works. But with the great increase in close range A.A. armament, the risk in the latter respect must be taken. In particular the very large increase in the close-range A.A. armament of "VANGUARD" necessitated fitting as a pom-pom a compartment just below the W.L. thought below the 6" armoured deck.

9. Since the A.W. torpedo-tubes of "HOOD" were suspected as contributing to the loss, it was proposed to remove these tubes from "RENOWN". Action has been taken to remove the forward tubes, but the after tubes are still on board.

10. Para 8 of the 1^st Sea Lord's minute of 1/2/42 is not understood. The derailed report M.0251/42, which contains the survivors' narratives, shows that in the first attack the ship was hit certainly by 3 and possibly by 4 torpedoes, and in the second attack, forty minutes later, by 4 torpedoes. British aircraft torpedoes that struck "BISMARCK" contained an explosive charge of 440lbs., whilse those fired by Destroyers contained an explosive charge of 750lbs. D.N.I. has stated on N.I.D. 04842/41 that Japanese aircraft torpedoes may contain an explosive charge as heavy as 867lbs., and it would appear, from a comparison of the damage caused by Japanese torpedoes to "PRINCE OF WALES" with other torpedo damage caused by German torpedoes and British charges used for experiments, that charges as large as 867lbs. Were used against "PRINCE OF WALES". Furthermore, "BISMARCK'S" standard displacement was at the very least 41,150 tons, compared with 37,500 tons of "PRINCE OF WALES", and ceteris paribus the larger the ship the better she can withstand underwater attack.

(Signed)

SV Goodall

13/2/42

- Page 78 -

Submitted

With reference to paragraph 7 of 1^st Sea Lord's minute of 1.2.42:-

What lessons were learnt from the destruction of HOOD.

D.N.O. concurs with D.N.C. and so far as the principal lesson is concerned has nothing to add to his remarks in paragraph 1 of his minute of 13.2.42. It is well known that if a ship is hit in the magazine and the shell explodes the magazine will blow up whether the charge is ignitered of not, or whether it is carried in a silk bag or brass case. Examples in Foreign Navies are the French Battleship BRETAGNE at Oran, the Italian Destroyer ARTIGLIERE, the American Battleship ARIZONA and Destroyer SHAW (photograph attached), also the German raider sunk by H.M.S.CORNWALL.

D.N.O's remarks are therefore confined to the other lessons leant and which have been examined under the following heads:-

Entry of flash into the magazine from a source outside the magazine.
Vulnerability of B.L. Charges during their passage from the magazine to the gun.

In general the penetration of the magazine by flash of shell or bomb explosion from a source outside the magazine, or of cordite fires being propagated from the gunhouse via the chain of cordite charges down through the turret to the magazines, is prevented by an elaborate system of flashtight arrangements.

HOOD provides no data about the efficiency of the flashtight arrangements fitted in that ship, as the short time which elapsed between the observation of the hit and the explosion occurring, indicates that the magazine was penetrated as a direct, and not indirect, effect of the shell burst.

In other ships, notably the SUFFOLK, our flashtight arrangements have proved successful. It must be emphasised however, that the efficiency of the flashtight arrangements in the turret is dependent on the structure itself not being wrecked or distorted by bomb blast. This point was well brought out in the case of the bomb damage to SUFFOLK already referred to. This leads to consideration under head (ii) - The vulnerability of B.L. Charges.

Unless a charge is contained in a covering which is flashtight and yet which is consumed in the gun, a charge must be exposed bare at some time in its passage from the magazines to the gun.

As the result of the lessons learnt at Jutland, it has been our practice up to the present to protect our heavy gun B.L. charges by passing them from one flashtight compartment to another. This system has proved successful provided the flashtight compartment is not distorted by blast.

A further point, although not directly a lesson learnt from the HOOD, was the possible source of danger in that by incorrect drill, and in contravention of the magazine regulations, too much cordite is being exposed in the magazines at one time. The attention of the Commanders-in-Chief was called to the necessity for particular care in this direction by Admiralty General Message.

What action has been taken on these lessons.

This is summarised as follows:-

Development of protective coverings for 15" charges for VANGUARD (Note:- In this ship the handling room is above the magazine.) Subject to satisfactory trial it is hoped to be able to apply this form of protection in all 15" ships.
Attention of Commanders-in-Chief drawn to the necessity for particular care in the strict compliance of magazine regulations as to the number of charges to be exposed out of their magazine cases at any one time.
The Ordnance Board have been asked to investigate the relative liability of the following types of propellant to accidental ignition by Flash:-
Cordite S.C.
Flashless
Nitro-cellulose.

(Note:- It is of interest that a sample of cordite ex GRAF SPEE was identified as being of the Nitro-glycerine type similar to our S.C Cordite.)

(1) Why present igniterless charges cannot be used in guns above 8 inch.

The use of powder igniters in 8 inch and 6 inch Mark XXIII guns has been superseded by igniterless charges with one inch tubes. In order to obtain satisfactory ignition with one inch tubes, a vent channel of diameter 0.4 inches is required.

When considering igniterless charges for guns above 8 inch it was established by trial that a one inch tube was inadequate to give sufficient ignition.

- Page 79 -

Minute Sheet No. 7

(Minutes continues from above)

Trials using a one and a quarter inch tube and a 0.4 inch vent channel were carried out in an experimental 12 inch gun. It was found that under these conditions severe erosion of the vent channel took place, resulting in rapid increase of the diameter of the vent channel to 0.5 inch. Previous trials had established the fact that if a gun with a vent channel of 0.5 inch diameter is fired with the vent unmasked, the resulting back flash is such as to cause material damage and to endanger the whole of the gun house crew. This therefore ruled out ingiterless charges with one inch tubes for guns above 8 inch calibre.

(2) In what manner the tinfoil covered igniters are likely to prevent a magazine going up.

The effect of the 3-ply non removable igniter cover (viz. Viz 2 layers of cashmere with a layer of tinfoil 0..1" in between) is to make the igniter no more susceptible to flash than the silk cloth covering the rest of the charge.

The Mark I Cartridge has a plate igniter with a tear off disc (or removable igniter cover).

The weakness of this lies in the fact that the tear off disc has to be removed in the handling room and the charge with exposed igniter is bare throughout its passage from the handling room to the gun.

As the result of trials carried out by EXCELLENT in 1933 it was established that a powder igniter covered by a tear off disc or a 3-ply non removable igniter cover was no more susceptible to flash than the body of the charge itself. These trials also showed that there was nothing to choose between the two types of cover in this respect.

The chief merit of the non removable igniter cover is that the powder igniter is never exposed. Moreover, the 15" Mark II Cartridge with the non removable igniter cover is fitted with a concentrated igniter, the surface area of which forms only 1/27 th of the surface are of the whole cartrisge.

What action is being taken to get an igniterless charge in guns above 8" and whether this matter is being treated as of transcending urgency.

It has not been found possible to adopt igniterless charges for guns above 8 incg for the reasons given in detail under head (c) (1) above.

With regard to the lines of V.C.N.S's minute of 5/12/41, examination of the damage caused to our ships by bursts of German shell shows that their burst effect is very much less than we expect from our shell as determined by trials.

In addition there have been several cases of German shell failing to give even explosion and there is some evidence to show that the exploder train in their shell is a weak point.

It is possible that the Germans have given too much weight to insensitivity of their shell firings against armour at the expense of bursting power.

HM/

PAT

RCW

HKS

16/2/42

(Signed)

Illegible

DIRECTOR OF NAVAL ORDNANCE

16 February, 1942

(Further Minute)

Concur generally with D.N.C. and D.N.O.

If a shell penetrates to and bursts in a magazine its contents will be exploded.

The only practical way to avoid this is to prevent entry by carefully positioning and effectively armouring such compartments.

This is done as far as practicable in modern designs.

2. In the case of the four "R" class battleships the fact remains that in similar circumstances to that of HOOD their loss is a probability. Much the same applies, but to a less extent, to RENOWN whose turret armour and belt are very light. In these old ships it is not practicable to keep modern heavy shells or bombs out of their magazines, and they are not really fit to stand up to punishment by such weapons. In addition the three reconstructed QUEEN ELIZABETH's are insufficiently armoured to ensure that a modern A.P. bomb will be kept out of their magazines.

3. Much time has been spent and many traila carried out in the past to reduce the chances of an accidental ignition of our gun charges by flame or flash.

D.N.O. shows that with the latest type of charge (having a concentrated igniter and non removable igniter cover) we have reduced the chances to what in effect is that of the igniterless type of charge used in the smaller calibres. The ignition of this type of charge, as also the igniterless type, is by no means an easy thing to do by fire or flash.

It is noted that at X of his minute V.C.N.S. remarks that:-

"the magazines in our ships have blown up on several occasions in this war and the last."

The attached statement '"' shows for this war the cases:-

Where magazines are known to have blown up.
Where magazines are suspected to have blown up.
Where they have not blown up in spite of severe damage.

In the first case there is only HOOD. In the second the evidence to support the view is in most cases scanty.

5. In paragraph 10 of his minute D.N.C. has set out the conclusions come to from an investigation carried out by the technical departments after a careful review of the evidence so far received from survivors of the "PRINCE OF WALES" and other ships present.

A full technical report is in course of preparation.

(Signed)

C.E.B.SIMEON

DEPUTY CONTROLLER

18.2.42.

- Page 80 -

First Sea Lord.

The papers dealing with this subject should reach you shortly. They are at present with I.M.N.G. (M.010643/41) to whom I referred them as he wrote the original minute. He tells me he is waiting to see the minutes of the Board of Enquiry into the loss of H.M.S.HOOD before remarking. These went with you to America but I hope will reach him shortly.

2. Briefly the situation is this:

Protection of magazines against direct hits.

Our latest ships are believed to be better protected than BISMARCK was and some extra protection to the sides of magazines is being added in future as a result of PRINCE OF WALES' action with BISMARCK.

Our older ships are vulnerable at the longer ranges. Some addition to deck armour has been made in one or two of the ROYAL SOVEREIGN Class.

D.N.C. considers that such action as water-jacketing magazines would not save a magazine from a hit which penetrated the armour. The Germans have not found any such expedient necessary.

3. Protection from flash.

Controller tells me the existing flash tight arrangements received a severe testing when ORION was bombed in a turret, and they proved satisfactory. EXETER was also hit in a turret during the GRAF SPEE action.

4. An Admiralty message has recently been sent to the Fleet pointing out the danger of an accumulation of B.L. charges out of their cases, such as might occur in action as a result of keenness to avoid loading delays. This may occur in magazines and also in supply train of smaller guns.

5. There remains the question of the cordite charges. We cannot change over to brass obturation for the last quarter charge of big guns, like the Germans, without a complete redesign of turrets and guns.

6. The alternative of igniterless charges has been considered over a period of years and adpoted in 8-inch and 6-inch guns in conjunction with 1-inch tubes, but this has not proved practicable in larger guns.

7. As an improvement, Capital ships have been modified to take a new type of B.L. cartridge with a concentrated igniter fitted with 3 ply non-removable igniter covers of tinfoil, etc. Supply to all ships is not yet complete.

8. D.N.O. is at present investigating further methods of protecting charges for these big guns.

9. After going into all these questions my feeling is:

Against direct hits in the magazine or their vicinity only armour is effective. It seems this was the cause of the loss of H.M.S.HOOD.

Against flash our existing arrangements have so far proved adequate but we should continue to try to solve the problem of obtaining an igniterless charge for guns above 8-inch.

(Signed)

R. McG

(Rear Admiral RR McGriggor, A.C.N.S.(Weapons))

22^nd January, 1942.

- Page 82 -

N.L.16248/41

A.C.N.S.(W)

You will see from his minute of the 4^th February enclosed that the First Lord agrees that this matter shall come before the Board and that a memorandum shall be prepared giving certain information which the First Sea Lord thinks the Board should have.

The First Sea Lord asks me to say that he would be glad if you would prepare the memorandum for the Board and send it through to the Controller. I will then arrange for its circulation as a Board Memorandum.

I see that the D.N.O. is asking for one of the back papers but I imagine they will be required for the production of the memorandum.

(Signed)

JSB

6^th February, 1942

- Page 83 -

Controller

With reference to First Sea Lord's note which I left with you yesterday, it would seem that most of the report required will have come from D.N.O. and D.N.C.

2. I am therefore sending you these papers now as I can not usefully deal with them at this stage.

(Signed)

R. McG

(Rear Admiral RR McGriggor, A.C.N.S.(Weapons))

7^th February, 1942

ACNS (W)

(Manuscript addition)

Remarks inserted.

BAF

19/2/42

- Page 84 continuing on to page 85 -

SECRET

First Sea Lord

(Through Controller)

(Initialled - BAF 24/2/42)

With reference to the First Sea Lord's minute of 1^st February, 1942 on N.L.16248/41, paragraph 7, the remarks from the Constructional and Ordnance aspects respectively are attached as Enclosures I and II.

2. It is desirable to draw the attention of the Board to the following additional points:

RODNEY, all QUEEN ELIZABETH Class, REVENGE, RAMILLIES and EREBUS have not yet got cartridges with concentrated igniters with non-removable igniter covers, and more than half of our 16" and 15" reserves of cartridges are also of the old type with spread igniters. RODNEY should receive the new type of cartridge during her present refit.
6 of our 8-inch cruisers still have cartridges with igniters and part of 8-inch reserves of cartridges are of the old type.
All new filling of 15" cartridges is to concentrated igniter design and 8" cartridges to igniterless design. Opportunities are being taken as latest type cartridges become available.
It will be noted that no solution has yet been found to the problem of providing igniterless charges for guns above 8-inch.

(Signed)

R. McG

(Rear Admiral RR McGriggor, A.C.N.S.(Weapons))

24^th February, 1942

- Page 86 -

First Sea Lord

First Lord

With regard to your minutes of the 27^th February and the 1^st March, it occurs to me that you may not have had particularly in mind that since your minutes of the 1^st and 4^th February were written it has been decided to set up the second Bucknill Committee to consider the material aspect of the loss by enemy action of capital and other heavy ships since the beginning of the war.

It occurs to me that if the Board now take a firm and final decision on the Board of Inquiry arising out of the loss of the HOOD the Bucknill Committee may feel somewhat fettered in their proceedings, particularly as the reports recently produced on the loss of the HOOD cover the material and technical side very fully. If, on the other hand, it should be decided to lay all this information before the Bucknill Committee ( as will be done with the information available about the other capital ship losses) it will still be open to the Board to take a final decision on the loss of HOOD in the light not only of the information at present available but of the observations and conclusions of the Bucknill Committee.

HVM

2^nd March, 1942

(Manuscript note below)

First Lord

I concur with "A" (Final sentence of the above minute) but I consider it desirable that the steps that have been taken to improve our ships should be discussed at the next Board meeting if you approve.

6/3

- Page 87 -

Secretary

Copy to: First Sea Lord

When I wrote my Minute of the 1^st March, I was not unmindful of the decision to set up the second Bucknill Committee.

I appreciate the point which you make; but I do not think the Committee need be embarrassed by the fact that the Board in the meantime had taken note of, and considered, the various steps put in hand by the Admiralty (e.g. on igniteless (sic) charges), in connection with the possible defects disclosed by the loss of the HOOD. They would remain entirely at liberty to suggest additional measures if they considered fit to do so.

I therefore consider that the Board should have before it at an early date, as proposed by the First Sea Lord, a Memorandum on the steps already taken.

AVA

8^th March, 1942

(Manuscript below)

Noted

Dep Sec for action

HVM 9.3.42

A suggested draft memoramdum for the Board attached

JSB

- Page 88 -

B.247

LOSS OF H.M.S.HOOD

MEMORANDUM FOR THE BOARD.

The Board are aware that the material aspect of the loss by enemy action of capital and other heavy ships since the beginning of the war is to be considered by the Bucknill Committee. This Committee will no doubt consider the circumstances attending the loss of the HOOD, and it will be open to the Board to take a final decision in the light not only of the information at present available but of the observations and the conclusions of the Bucknill Committee. In the meantime the First Sea Lord considers it desirable that the steps which have been taken to improve our ships should be discussed at a Board meeting. The First Lord agrees and considers that the Board should regard themselves as entirely at liberty to suggest additional measures now if they consider fit to do so.

A report on the action already taken is contained in a memorandum submitted by A.C.N.S. (W), which forms the third enclosure to this memorandum. In order that the Board may have full information bearing on the question the following are circulated herewith:-

Enclosure 1.

The report of the Second Board of the Enquiry into the loss of Hood

Enclosure 2.

Minutes of A.C.N.S. (W), V.C.N.S., Controller, 1^st Sea Lord and First Lord thereon.

Enclosure 3.

The note by A.C.N.S. (W) already referred to with enclosures based on reports by D.N.C. and D.N.O.

Enclosure 4.

An extract from D.N.C'S report dealing specifically with para. 8 of 1^st Sea Lord's minute of 1^st February (Enclosure 2.)

Enclosure 5.

An extract from a minute by Deputy Controller.

And appended statement.

HVM

10^th February, 1942.