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

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

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