These guns were intended for the "H" class battleships which were laid down in 1939 but never completed. This weapon was a good design, but it could be said that it had an excessively high muzzle velocity, hence giving it minimal deck penetration even at long ranges.
Accounts differ as to the actual number of guns completed, but there appears to have been twelve. There were three versions of this weapon; the original prototype for proof and experimental testing; three guns built to the naval pattern and intended for the "H" battleships; and eight finished to a modified design for coastal artillery use and also known as Adolph. The coast artillery version had a similar construction to the naval version but with a larger chamber. The naval guns were completed as one left hand and two right hand. Only one of these had power ramming.
The eight coastal artillery guns were sent to Norway to be employed to protect Narvik and Tromsø, with one gun being lost in transit. Of the remaining seven guns, three were emplaced as Battery Dietl on the island of Engeløya and the other four were mounted as Battery Trondenes near Harstad. At the end of the war, the guns were taken over by the Norwegian Army along with 1,227 shells. A German gun crew trained the Norwegians in their use and the guns were actively used for about a decade. The three guns at Battery Dietl were decommissioned in the early 1950s and then scrapped in 1956. The battery at Trondenes was last fired in 1957 and formally taken out of commission in 1961. The guns then sat idle and were placed on sale for scrapping in 1968, but they still remain in place and one of them is currently open as a museum at Trondenes Fort.
The three naval guns were placed on railway mounts and two of these were to be sent to the Hel Peninsula in Poland, but eventually all three were made part of Battery Lindemann. This was located near Sangatte in France where they often fired across the Channel at Dover.
As this gun had a rather thick barrel for its size, during the redesigns of the "H" class battleships during 1941 and 1942 (H-41 and H-42) it was proposed to bore them out and convert them into 42 cm/48 (16.54") weapons. One of the reasons behind this conversion was that this change would give these ships a larger caliber weapon than those planned for any known Allied battleship. None of the guns already built were ever converted and no new guns were started. The SK C/40 model year for this version is my estimate.
Constructed of a loose barrel, which was universally interchangeable between production guns, a loose liner which only fitted a particular gun, B tube, a jacket over the rear end of B tube, a breech end-piece thrust over the jacket and kept in place by a threaded ring, a breech block supporting piece inserted in the breech end-piece and secured by a threaded ring. A retaining ring with two fittings for transmitting rotation forces was screwed onto the rear of the barrel. Used a horizontal sliding breech block, similar to other large-caliber German naval guns.
The data that follows is specifically for the 40.6 cm (16") Naval version except where noted. Actual bore diameter of all versions was 40.64 cm (16.0").
|Designation||40.6 cm/52 (16") SK C/34
42 cm/48 (16.54") SK C/40
|Ship Class Used On||"H" Class|
|Date Of Design||1934|
|Date In Service||1942 as coastal defense guns|
|352,516 lbs. (159,900 kg) including hornrings|
|Gun Length oa||831.9 in. (21.130 m)|
|Bore Length||777.6 in. (19.750 m)|
|Rifling Length||Naval Guns: 671.9 in. (17.066 m)
Coastal Guns: 664.2 in (16.871 m)
|Grooves||Naval Guns: (110) 0.236 in deep x 0.323 in (5 mm x 8.2 mm)
Coastal Guns: (90) 0.189 in deep x 0.314 in (4.8 mm x 7.98 mm)
|Lands||0.277 in (7.03 mm )|
|Twist||Increasing RH 1 in 35.9 to 1 in 29.9|
|Chamber Volume||Naval Guns: 25,630 in3 (420 dm3)
Coastal Guns: 28,071 in3 (460 dm3)
|Rate Of Fire||about 2 rounds per minute|
The sliding breech block weighed 7,940 lbs. (3,600 kg), the barrel 91,710 lbs. (41,600 kg) and the liner 45,860 lbs. (20,800 kg). The prototype gun differed in that the barrel weighed 83,110 lbs. (37,700 kg) and the liner 38,360 lbs. (17,400 kg).
|Type||Cartridge - Bag|
|Projectile Types and Weights||Naval Projectiles
APC L/4,4 - 2,271 lbs. (1,030 kg)
HE L/4,6 base fuze - 2,271 lbs. (1,030 kg)
HE L/4,4 nose fuze - 2,271 lbs. (1,030 kg)
Special Coastal Artillery Projectiles
|Bursting Charge||APC L/4,4 - about 53.4 lbs. (24.2 kg)
HE L/4,6 base fuze - about 93.1 lbs. (42.2 kg)
HE L/4,4 nose fuze - about 181.7 lbs. (82.4 kg)
|Projectile Length||APC L/4,4 - 70.3 in (178.6 cm)
HE L/4,6 base fuze - 73.5 in (186.7 cm)
HE L/4,4 nose fuze - 76.7 in (194.9 cm)
Adolph HE L/4,2 - 67.1 in (170.5 cm)
|Propellant Charge||Fore: 295.4 lbs. (134 kg) RPC/38 (22/11)
Main: 282.2 lbs. (128 kg) RPC/38 (22/11)
Brass case for main charge: 201 lbs. (91 kg)
During the war, the coastal guns switched to the following:
Fore: 361.6 lbs. (164 kg) RPC/40 (12.5/4.2)
|Muzzle Velocity||For naval shells: 2,657 fps (810 mps)
For light coastal artillery shells (new gun): 3,445 fps (1,050 mps)
For light coastal artillery shells (average gun): 3,084 fps (940 mps)
|Working Pressure||20.3 tons/in2 (3,200 kg/cm2)|
|Approximate Barrel Life||180 - 210 rounds|
|Ammunition stowage per gun||120 rounds|
- These guns, like most large caliber German guns, used a "fore charge" which was propellant in a silk bag, and a "main charge" which was propellant in a brass case. The brass case helped to seal the breech of the gun.
- The case for the main charge was changed to mild steel late in the war.
- Fore and Main charges were rammed together.
- The horizontal sliding breech block weighed 7,937 lbs. (3,600 kg).
- Actual Projectile designations were as follows:
APC - Psgr. L/4,4 (mhb)
HE base fuze - Spr.gr. L/4,6 Bdz (mhb)
HE nose fuze - Spr.gr. L/4,4 Kz (mhb)
Adolph HE L/4,2 - Ad.gr. L/4,2 Bdz u. Kz (mhb)
HE L/4,1 base and nose fuze - Spr.gr. L/4,1 Bdz u. Kz (mhb)
|Range @ 30 degrees||39,800 yards (36,400 m)|
|Range @ 33 degrees
(max elevation of naval turret)
|40,245 yards (36,800 m)|
|Range @ 52 degrees
|47,025 yards (43,000 m)|
All of the 2,271 lbs. (1,030 kg) projectiles had similar maximum ranges.
|Range @ 52 degrees
Muzzle Velocity of 3,445 fps (1,050 mps)
|61,240 yards (56,000 m)|
|Range @ 50 degrees
Muzzle Velocity of 3,084 fps (940 mps)
|47,620 yards (43,550 m)|
|Range||Side Armor||Deck Armor|
|0 yards (0 m)||31.7" (805 mm)||---|
|10,000 yards (9,144 m)||25.1" (638 mm)||1.4" (36 mm)|
|20,000 yards (18,288 m)||18.8" (457 mm)||3.2" (81 mm)|
|30,000 yards (27,432 m)||13.6" (345 mm)||5.0" (127 mm)|
|40,000 yards (36,576 m)||10.2" (259 mm)||8.5" (216 mm)|
This data is from "Battleships: Axis and Neutral Battleships in World War II" for a muzzle velocity of 2,657 fps (810 mps) and is based upon the USN Empirical Armor Penetration Formula.
"H" (4): Drh LC/34
Single BSG Coastal Artillery
|Weight||1,452 tons (1,475 mt)|
|Drh LC/34: -5.5 / +30 degrees
Schiessgerät C/39: -5 (?) / +55 degrees
|Train||+145 / -145 degrees|
The sources listed below differ as to the actual elevation span of the ship turrets. I have chosen to use those figures given in "German Capital Ships of World War Two."
"Naval Weapons of World War Two" by John Campbell
"The Illustrated Encyclopedia of 20th Century Weapons and Warfare" by Bernard Fitzsimmons
"Battleships: Axis and Neutral Battleships in World War II" by W.H. Garzke, Jr. and R.O. Dulin, Jr.
"German Warships 1815-1945" by Erich Gröner
"Naval Guns: 500 years of Ship and Coastal Artillery" by Hans Mehl
German Naval Guns: 1939 - 1945" by Miroslaw Skwiot
"German Capital Ships of World War Two" by M.J. Whitley
"Schlachschiff H" document by Dipl Ing Otto Riedel
Special help from Cliff McMullen, Peter Lienau and Charles Schedel