4.7 inch Mark 12
 |
| The "A" and "B" mounts of a destroyer. The turrets are positioned on "look-out" bearings. |
| Gun specs | |
| Gun type | Mark 12 LA |
| Purpose | Low Angle only |
| Bore | 120 mm |
| Classes used on | N-class destroyers |
| Date of design | 1934 ( in service with RN 1936 ) |
| Date in service with RNN | 1942 |
| Length | 45 calibres ( 5,6 m ) |
| Gunweight | 3 tons |
| Initial velocity | 2650 feet/sec |
| Rate of fire | 10 rounds/minute ( 12 with power ramming ) |
| Shell specs | |
| Shell types | HE ( High Explosive ) |
| SAP ( Semi-Armour Piercing ) | |
| Shell weight | 50 lbs |
| Range | 15.500 m ( 17000 yards ) @ 40 degrees |
| Mount specs | |
| Mount type | Twin Mount Mark 19 CP |
| Mount armor | - |
| Mount weight | 25,5 tons |
| Elevation | -10 / + 40 degrees |
| Train | - 160 / + 160 degrees |
| Train rate | 10 degrees/sec |
| Train method | Manual |
| Diagram | |
 |
|
| Mark 19 mount | |
| A | Trainer's monocular sight |
| B | Hydraulic exhaust take-off from elevating structure |
| C | Trainer's power handweel |
| D | Trainer's hand drive |
| E | Training receiver |
| F | Drive to training reiver mechanical pointer |
| G | Fuze setter's seat |
| H | Fuze setter pedestal |
| I | Loading tray unlocking palm lever |
| J | Loading tray |
| K | Hand rammer head |
| L | Power rammer head |
| M | Rammer cylinder |
| N | Spent cartridge catch net |
| O | Intensifier, connected to recupterator cylinder gland |
| P | Balance weight |
| Q | Recuperator cylinder |
| R | Loading light |
| S | Semi-automatic/quickfire changeover lever |
| T | Recuperator ram |
| U | Breech mechanism lever locking lever |
| V | Safe fire lever |
| W | Breech mechanism lever |
| X | Rounds fired counter |
| Y | Breech worker's percussion firing hand-grip |
| Z | Firing circuit interceptor |
| Back | Home |