keltos01
04-21-10, 12:34 AM
http://img694.imageshack.us/img694/4526/wnbr440mk12thunderboltp.jpg (http://img694.imageshack.us/i/wnbr440mk12thunderboltp.jpg/)
HMS Thunderbolt with 4"/40 (10.2 cm) Mark XII in 1941
Photograph copyrighted by John Lambert
First introduced on the rearmed scout cruiser Foresight in 1913, the Mark IV armed many destroyers and flotilla leaders of World War I. The Mark IV developed a reputation during World War I for repeatedly jamming. The Marks XII, XII* and XXII were an interchangeable series of guns based upon the Mark IV, but specially adapted for "wet mountings" on submarines. The first Mark XII was issued to submarine L33 in October 1919.
http://img203.imageshack.us/img203/1401/wnbr440mk4l33pic.jpg (http://img203.imageshack.us/i/wnbr440mk4l33pic.jpg/)
4"/40 (10.2 cm) on Submarine L33
Note how the entire gun platform rotated with the gun, thus ensuring adequate working space
Photograph from the collection of Dave Perkins and used here by his permission
The Mark IV was constructed of inner A tube, A tube, jacket and breech ring and was partly wire wound. This gun had a horizontal sliding breech block with semi-automatic operation. The Mark IV* had a strengthened breech ring, but this distinction was discontinued after a short time. Mark XII had a tapered inner A tube, A tube, wire for about half the length, jacket over more than half the length and a breech ring. The Mark XII* and Mark XXII had monobloc barrels and had a manually-operated horizontal sliding breech block. The Mark XII* had no muzzle bell and the breech ring was shaped while the Mark XXII had a muzzle bell and a rectangular breech ring.
http://www.navweaps.com/Weapons/WNBR_4-40_mk4.htm
http://img220.imageshack.us/img220/1206/0206d.jpg (http://img220.imageshack.us/i/0206d.jpg/)
http://img232.imageshack.us/img232/2413/0207z.jpg (http://img232.imageshack.us/i/0207z.jpg/)
4" submarine deck gun, probably for a T class submarine - Image Date:c.1939
http://www.dockmuseum.org.uk/archive/browser.asp?subject=&title=&subtitle=&searchtype=1&deepcriteria=submarine+deck+gun+1939
4" Mk XII submarine gun in workshop - Image Date:1944 :
http://img341.imageshack.us/img341/802/6399.jpg (http://img341.imageshack.us/i/6399.jpg/)
http://img24.imageshack.us/img24/4606/6398h.jpg (http://img24.imageshack.us/i/6398h.jpg/)
http://img693.imageshack.us/img693/8907/6400l.jpg (http://img693.imageshack.us/i/6400l.jpg/)
http://img339.imageshack.us/img339/3174/6402x.jpg (http://img339.imageshack.us/i/6402x.jpg/)
http://www.dockmuseum.org.uk/archive/browser.asp?subject=&title=&subtitle=&searchtype=1&deepcriteria=mk+xii
keltos
HMS Thunderbolt with 4"/40 (10.2 cm) Mark XII in 1941
Photograph copyrighted by John Lambert
First introduced on the rearmed scout cruiser Foresight in 1913, the Mark IV armed many destroyers and flotilla leaders of World War I. The Mark IV developed a reputation during World War I for repeatedly jamming. The Marks XII, XII* and XXII were an interchangeable series of guns based upon the Mark IV, but specially adapted for "wet mountings" on submarines. The first Mark XII was issued to submarine L33 in October 1919.
http://img203.imageshack.us/img203/1401/wnbr440mk4l33pic.jpg (http://img203.imageshack.us/i/wnbr440mk4l33pic.jpg/)
4"/40 (10.2 cm) on Submarine L33
Note how the entire gun platform rotated with the gun, thus ensuring adequate working space
Photograph from the collection of Dave Perkins and used here by his permission
The Mark IV was constructed of inner A tube, A tube, jacket and breech ring and was partly wire wound. This gun had a horizontal sliding breech block with semi-automatic operation. The Mark IV* had a strengthened breech ring, but this distinction was discontinued after a short time. Mark XII had a tapered inner A tube, A tube, wire for about half the length, jacket over more than half the length and a breech ring. The Mark XII* and Mark XXII had monobloc barrels and had a manually-operated horizontal sliding breech block. The Mark XII* had no muzzle bell and the breech ring was shaped while the Mark XXII had a muzzle bell and a rectangular breech ring.
http://www.navweaps.com/Weapons/WNBR_4-40_mk4.htm
http://img220.imageshack.us/img220/1206/0206d.jpg (http://img220.imageshack.us/i/0206d.jpg/)
http://img232.imageshack.us/img232/2413/0207z.jpg (http://img232.imageshack.us/i/0207z.jpg/)
4" submarine deck gun, probably for a T class submarine - Image Date:c.1939
http://www.dockmuseum.org.uk/archive/browser.asp?subject=&title=&subtitle=&searchtype=1&deepcriteria=submarine+deck+gun+1939
4" Mk XII submarine gun in workshop - Image Date:1944 :
http://img341.imageshack.us/img341/802/6399.jpg (http://img341.imageshack.us/i/6399.jpg/)
http://img24.imageshack.us/img24/4606/6398h.jpg (http://img24.imageshack.us/i/6398h.jpg/)
http://img693.imageshack.us/img693/8907/6400l.jpg (http://img693.imageshack.us/i/6400l.jpg/)
http://img339.imageshack.us/img339/3174/6402x.jpg (http://img339.imageshack.us/i/6402x.jpg/)
http://www.dockmuseum.org.uk/archive/browser.asp?subject=&title=&subtitle=&searchtype=1&deepcriteria=mk+xii
keltos