5.5" Secondary Guns
Gun Type: Mk I
Calibre: 5.5 inch / 13.97 cm
Barrel Length: 50 cal (275") / 698.5 cm
Gun Length (Overall): 284.7" / 7,232 mm
Barrel Rifling: 40 grooves, right handed twist
Charge Type: Cordite MD19
Full Charge Weight/Mass: 22 lbs 4 oz / 10.1 kg
Reduced Charge Mass: 13 lbs 13oz / 6.3 kg
Shell Weight: 82 lbs / 37.2 kg
Chamber Gas Pressure: 18 tons psi / 289 MPa
Muzzle Velocity (full charge): 2790 fps / 850 mps
Rate of Fire: 8-12 shots per minute
Max. Range (New Barrel): 18,500 yds / 16,916 m (at 30°)
Elevation Angle (Max. / Min.): 30° / -05°
Mount: Mk II
Control: Guns were primarily controlled by the 5.5" directors. These consisted of 9 ft/2.75 m rangefinders and pedestal type sites. Additional inputs could be taken from Evershed bearing indicators. Inputs from all sources were fed to the 5.5" Transmitting Station which could then coordinate the gun fire. Guns could also be manually aimed/directed.
Comments: These guns were built by Coventry Ordnance Works. As completed, Hood carried 12 guns (Serial Numbers 17, 24, 31, 49, 56, 57, 75, 76, 78,79, 83 and 85). Gun number 83 developed chamber flaws and was replaced with gun number 86 in 1928. In 1935, all but one gun (number 86) were removed and replaced with other guns (she then carried serial numbers 1, 2, 4, 5, 6, 7, 8, 9, 19, 18, 23 and of course 86). Guns 7 and 8 (located on the forward Shelter Deck) were temporarily removed in 1938 and replaced by single barrel 4" guns. This remained in effect until 1939 when the two 4" guns were removed and 5.5" guns 7 and 8 were reinstalled. All 5.5" guns and mounts were completely removed in May 1940.
Many of these guns went on to serve elsewhere in Coastal Defence roles as indicated below:
- Numbers 56 and 78 were sent to Ascension Island
- Numbers 17 and 75 transferred to Army and sent to Bognor
- Numbers 24, 31 and 49 transferred to Army and sent to Pevensy
- Numbers 1, 2, 4 and 5 transferred to Army and sent to North Foreland
- Numbers 6, 7, 9 and 23 transferred to Army and sent to Dover
- Numbers 8, 10 and 18 transferred to Army and sent to Folkestone
- Numbers 83 and 85 transferred to Army and sent to Coalhouse Fort, Tilbury
- Numbers 80, 81 and 82 (initially fitted to Hood during her construction, but removed in 1919 before she was completed) were fitted in Hermes and later lost with the ship
Of all these 5.5" guns, only two are believed to still exist today- these are the guns of Ascension Island's Hood Battery. This information is per the 5.5in Gun List GL22, Priddy's Hard Archive, Hampshire Record Office, Winchester, UK. Special thanks to John Roberts for looking this data up for us.
High Angle/Low Angle Twin 4"Guns
Gun Type: Mk XVI
Calibre: 4" / 10.2 cm
Number of Barrels: 2
Barrel Length: 45 cal 180") / 457.2 cm
Gun Length (Overall): 190.6" / 484.1 cm
Barrel Rifling: 32 grooves, right hand twist
Charge: Cordite SC
Charge Weight: 9lbs / 4.1 kg
Gas Pressure: 18.5 tons psi / 297 MPa
Bullet Weight (High Explosive): 35.9 lbs /16.3 kg
Muzzle Velocity: 2650 fps / 807.7 mps
Rate of Fire: 16 - 18 per minute
Max. Range: 21,300yds / 19,476.7 m at 45°
Ceiling: 40,000ft / 12,192 m at 80°
Elevation (max. / min.): 80° / 10°
Mount: Mk XIX
Fire Control: HACS Mk III* (one atop After Superstructure and two on the Admirals Signal Deck /main bridge -registered numbers 44, 45 and 46). The HACS Mk III* directors were equipped with 15 ft/4.6 m. The guns could also be individually locally directed. Click on the lower image to the right to see the HACS Mk III* director.
Comments: Four of these were first fitted to the Shelter Deck in 1937. An additional three were fitted to the Shelter Deck in 1940. The disposition was as follows- three emplacements to port (from front to rear known as mounts "P1", "P2" and "P3" or "L1", "L2" and "L3") , three to starboard ("S1", "S2" and "S3" or "R1", "R2" and "R3") and one at the very end of the Shelter Deck on the centreline ("Number 4"). Hood carried these seven gun emplacements to the end. Although technically dual purpose guns (their high angle capability was used to engage aircraft, and their low angle capability enabled them to be used against surface targets), they were better suited as anti-aircraft guns.