The 15 inch Coast Gun was originally designed as a Naval gun in 1915. In the 1920’s it was decided to use the guns in the new fortress at Singapore. It was formally introduced for land service in February 1936. Three guns were approved for Johore Battery and two for Buona Vista Battery. Two more for Penang were never installed. In 1940 these two guns were installed at Dover at the Wanstone Battery. The guns were wire wound, 42 calibre guns of conventional design. The barbette style Mark 1 mounting with full power operation was introduced in 1937. Ammunition was kept in underground magazines and lifted to the gun by hydraulics. At Dover, the 15 inch Coast Gun was declared obsolete in 1959.
Mounting
Mark 1
Original mounting
Mark 2
Completely enclosed turret. Used with Buona Vista Battery
Mark 3
Not officially introduced. Slightly simplified version of Mk 2. Wanstone Battery
Data
Weight of Gun & Breech Mechanism
100 tons
Total length
442.35 inches
Length of Bore
635.8 inches (42.4 calibres)
Rifling
76 grooves, uniform Right Hand 1/30
Breech mechanism
Astbury interrupted screw, electric or percussion fired
Elevation
-2º to +45º
Traverse
240º
Recoil system
Hydropneumatic , constant 45 inches
Weight in action
373 tons
Rate of Fire
2 rounds per minute
Performance
Firing standard 1938 lbs APC Shell
Muzzle velocity, normal charge
2,400 feet per second
Muzzle velocity, super charge
2,680 feet per second
Maximum range, normal charge
36,900 yards
Maximum range, super charge
36,700 yards
Ammunition
Shell, APC Mark 17B
Naval origin. Capped, piercing shell 1,938 lbs
Shell, HE BNF Mark 7B
Streamlined shell with both base & nose fuzes (BNF)
Propelling charge
Four quarter charge bags each of 432 lbs of Cordite. Super Charge (Dover gun only) four quarter charge bags each of 490 lbs of Cordite
