Netherlands
12 cm/45 (4.724") Mark 8
Updated 01 August 2006
An AAA weapon that was used only on ships built for the Germans during World War II, but the ships that survived the war were then commissioned into the Netherlands Navy.  This gun was used on a Bofors designed triaxial mount for the twin mountings.  These were criticized by the Germans as being overloaded as the cross-level axis carried not only most of the shield but also the very heavy casing for the dredger hoists.

Apparently built with a loose barrel, jacket and removable breech ring and had a vertical sliding breech-block.  May have been a derivative of the Bofors Model 1924C which was manufactured under license by Wilton-Fijenoord.
WNNeth_47-45_m8_K3_pic.jpg

RNN Van Spejik after World War II
This ship served in the Kriegsmarine as K3 during World War II
Royal Netherlands Navy Photograph
.
Gun Characteristics
.
Designation 12 cm/45 (4.724") Mark 8
Built by Wilton-Fijenoord
Ship Class Used On ZH1 (ex-Gerard Callenburgh) and Z1 destroyer classes
K3 sloop/gunboat (RNN Van Spejik, post war)
Date Of Design about 1940
Date In Service 1942
Gun Weight 3.35 tons (3.4 mt)
Gun Length oa N/A
Bore Length about 212.6 in (5.400 m)
Rifling Length N/A
Grooves N/A
Lands N/A
Twist N/A
Chamber Volume N/A
Rate Of Fire 10 rounds per minute
.
Ammunition
.
Type Fixed
Weight of Complete Round HE - 70.5 lbs. (32 kg)
Projectile Types and Weights HE - 45.2 lbs. (20.5 kg)
Bursting Charge N/A
Projectile Length N/A
Propellant Charge 11 lbs. (5 kg)
Cartridge - 25.3 lbs. (11.5 kg)
Muzzle Velocity HE - 2,625 fps (800 mps)
Working Pressure N/A
Approximate Barrel Life N/A
Ammunition stowage per gun N/A
.
Range
.
Elevation With 45.2 lbs. (20.5 kg) HE Shell
Range @ 45 degrees about 21,300 yards (19,500 m)
.
Mount / Turret Data
.
Designation Single Mount
   ZH1: (1)

Twin Mount
   ZH1:  (2)
   K3:  (2)
Weight  Bofors Triaxial Twin:  57 tons (58 mt)
Others:  N/A
Elevation about -5 / +45 degrees (estimate)
Elevation Rate Manually operated, only
Train about +150 / -150 degrees
Train Rate Manually operated, only
Gun recoil N/A
.
Data from
"Naval Weapons of World War Two" by John Campbell
"Destroyers of World War Two" by M.J. Whitley
"Warship Pictorial:  The Royal Netherlands Navy:  1945-86" article in "Warships Volume X"