The 8 inch Coast Gun was an ex-naval Mark 8 gun acquired by the army. Only two batteries were built in the UK at Capel and Hougham in the Folkestone/Dover area. Each mounted three guns. They were in service from 1942 until 1952.
The guns were 50 calibres in length and of conventional design. The mountings were fully powered including breech opening and ramming. They had a remarkable maximum elevation of 70º. Although this was not of any use for coast defence it was put to use in an anti-aircraft role. Whether the 8 inch Coast Gun was effective in this role or not, nobody knows.
Gun
| Mark 8 | Wire wound. Fitted with washout & air blast gear |
| Mark 8* | Built up construction without wire |
| Mark 8** | The inner “A” tube tapered to ease withdrawl |
Data
| Weight of Gun & Breech Mechanism | 38,528 lbs |
| Total length | 413.1 inches |
| Length of Bore | 400 inches (50 calibres) |
| Rifling | 48 grooves, uniform Right Hand 1/30 |
| Breech mechanism | Parallel screw, hand or hydraulic operation, electric fired |
| Elevation | -3º to +70º |
| Traverse | 80º right & left |
| Recoil system | Hydropneumatic , constant 24 inches |
Performance
Firing standard 256 lbs APC Shell
| Muzzle velocity | 2,725 feet per second |
| Maximum range | 29,200 yards |
Ammunition
| Nose fuzed, TNT filled | Conventional nose-fuzed with Lyddite filling. Fitted with Percussion Fuze No. 45P |
| Propelling charge | Filled with 2,500 lead/antimony balls & 2 lbs gunpowder expelling charge. Mostly used in practice & obsolete during the war |
| Propelling charge | Single bag charge of 66 lbs Cordite with gun powder igniter in base |