Germany
30.5 cm/50 (12") SK L/50
Updated 28 December 2008
These guns were fitted to many battleships and battlecruisers completed just before and after the start of World War I.  When compared to contemporary British guns in terms of penetrating power, they were superior to the 12"/45 (30.5 cm) and 12"/50 (30.5 cm) guns, and only slightly less powerful than the 13.5" (34.3 cm) guns.  They were, of course, completely outclassed by the 15"/42 (38.1 cm) guns used on the Queen Elizabeth class.

The battlecruisers Derfflinger and Lützow used these weapons at the Battle of Jutland (Skagerrak) to sink the British battlecruisers HMS Queen Mary and HMS Invincible.

  The mountings for these guns used electric pumps to drive hydraulic elevation gear while the training was all electric.  These guns also had hydraulically worked rammers and breeches, the first fitted to German large-caliber guns.  These changes increased the rate of fire, with most ships having a ROF of 20 seconds while the Kaiser class were reported to have had an overall ammunition supply speed of three rounds in 48 seconds, including all transfers.

In World War II these guns were used only as coastal artillery.  They were then supplied with a more streamlined shell and used a larger propellant charge, giving them increased range.  The best known battery was the six-gun Friedrich August at Wangerooge.  Later, three of these guns on BSG mountings were moved to near Wimille on the Channel Coast.

Constructed from shrunk on tubes and hoops and used the Krupp horizontal sliding wedge breech block.

Actual bore diameter was 30.50 cm (12.008").
WNGER_12-50_skc12_Koenig_pic.jpg

Aft turrets of SMS König
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Click here for additional Pictures
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Gun Characteristics
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Designation 30.5 cm/50 (12") SK L/50
Ship Class Used On Helgoland, Kaiser, König and Derfflinger Classes
Date Of Design 1908
Date In Service 1911
Gun Weight
(see Note)		 114,309 lbs. (51,850 kg)
Gun Length oa 600.4 in (15.250 m)
Bore Length 569.3 in (14.461 m)
Rifling Length 465.0 in (11.805 m)
Grooves 88
Lands N/A
Twist N/A
Chamber Volume For 551 lbs. (250 kg) shells:  12,052 in3 (197.5 dm3)
For 892.9 lbs. (405 kg) shells:  12,205 in3 (200.0 dm3)
Rate Of Fire 2 - 3 rounds per minute
Note:  The often-seen figure of 171,079 lbs. (77,600 kg) for this weapon actually includes the weight of the Weige (gun cradle).
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Ammunition
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Type Cartridge - Bag
Projectile Types and Weights World War I
   APC L/3,1 - 894 lbs. (405.5 kg)
   HE L/4 - 894.8 lbs. (405.9 kg)

World War II
   APC L/3,4 - 892.9 lbs. (405 kg)
   APC L/4,9 - 915 lbs. (415 kg)
   HE L3,8 base fuze - 915 lbs. (415 kg)
   HE L/5 base fuze - 915 lbs. (415 kg)
   HE L/4,8 nose fuze - 892.9 lbs. (405 kg)

Special Coastal Artillery Projectile
   HE L/3,6 base and nose fuze - 551 lbs. (250 kg)
Bursting Charge World War I
   APC L/3,1 - 30 lbs. (13.6 kg)
   HE L/4 - N/A

World War II
   APC L/3,4 - 25.4 lbs. (11.5 kg)
   APC L/4,9 - N/A
   HE L/3,8 base fuze - N/A
   HE L/5 base fuze - N/A
   HE L/4,8 nose fuze - 58.4 lbs. (26.5 kg)
   HE L/3,6 base and nose fuze - 32.0 lbs. (14.5 kg)
Projectile Length World War I
   APC L/3,1 - 37.4 in (95 cm)
   HE L/4 - 48.23 in (122.5 cm)

World War II
   APC L/3,4 - 40.8 in (103.7 cm)
   APC L/4,9 - 58.8 in (149.5 cm)
   HE L/3,8 base fuze - 45.6 in (115.9 cm)
   HE L/5 base fuze - 60.0 in (152.5 cm)
   HE L/4,8 nose fuze - 52.6 in (133.5 cm)
   HE L/3,6 base and nose fuze - 55.1 in (140 cm)
Propellant Charge World War I
   Main Charge:  201 lbs. (91 kg) RP C/12
   Fore Charge:  76 lbs. (34.5 kg) RP C/12

World War II (as of 1940)
   For APC L/3,4 and HE L/4,8 nose fuze
      Main Charge - 188.3 lbs. (85.4 kg) RP C/32
      Fore Charge - 91.7 lbs. (41.6 kg) RP C/32

   For HE L/3,6 base and nose fuze
      Main Charge - 188.3 lbs. (85.4 kg) RP C/32
      Fore Charge - 135.8 lbs. (61.6 kg) RP C/32

   Total main cartridge weight:  313 lbs. (142 kg)
   Silk bag for fore charge:  5.3 lbs. (2.4 kg)

After 1942 (see Note 3)
   APC L/4,9 - 268 lbs. (121.5 kg) RP C/38 (18/8)
   HE L/3,6  - 315 lbs. (143 kg) RP C/38 (18/8)
Muzzle Velocity World War I
   2,805 fps (855 mps)

World War II
   APC L/3,4 - 2,805 fps (855 mps)
   APC L/4,9 - 2,789 fps (850 mps)
   HE L3,8 base fuze - 2,789 fps (850 mps)
   HE L/5 base fuze - 2,789 fps (850 mps)
   HE L/4,8 nose fuze - 2,805 fps (855 mps)
   HE L/3,6 base and nose fuze - 3,675 fps (1,120 mps)
Working Pressure 20.9 tons/in2 (3,300 kg/cm2)
Approximate Barrel Life 200 rounds
Ammunition stowage per gun Helgoland:  85 rounds
Kaiser:  86 rounds
König and Derfflinger:  90 rounds
Notes:

1) These guns, like most large caliber German guns of this era, used a "fore charge" which was propellant in a double bag silk case and a "main charge" which was propellant in a brass case.  The brass case helped to seal the breech of the gun.

2) APC shells were painted blue, HE yellow and Training red.  A black painted nose indicated that the shell was armed.

3) I lack the break down between fore and main charges for the 1942 propellant charges.

4) Outfit for Derfflinger class was 65 AP and 25 HE per gun.

5) Actual Projectile designations were as follows:

World War I
   APC L/3,1 - Psgr. L/3,1
   HE L/4 - Spr.gr. L/4

World War II
   APC L/3,4 - Psgr. L/3,4
   APC L/4,9 - Psgr. L/4,9 (mhb)
   HE L/3,8 base fuze - Spr.gr. L/3,8 Bdz
   HE L/5 base fuze - Spr.gr. L/5 Bdz
   HE L4,8 nose fuze - Spr.gr. L/4,8 Kz
   HE L/3,6 base and nose fuze - Spr.gr. L/3,6 Bdz u. Kz (mhb)

Diagrams of some of these projectiles and their fuzes and charges may be found at the additional pictures link above.
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Range during World War I
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Elevation With 894 lbs. (405.5 kg) APC L3,1 Shell
Range @ 13.5 degrees 17,717 yards (16,200 m)
Range @ 16.0 degrees 22,310 yards (20,400 m)
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Range during World War II
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Elevation With 892.9 lbs. (405 kg) APC L3,4 Shell
Range @ 45.0 degrees 35,000 yards (32,000 m)
Elevation With 915 lbs. (415 kg) APC L4,9 Shell
Range @ 49.2 degrees 45,166 yards (41,300 m)
Range @ 50.0 degrees 43,200 yards (39,500 m)
Elevation With 551 lbs. (250 kg) HE L3,6 Shell
Range @ 49.1 degrees 56,200 yards (51,400 m)
Notes:

1) All entries in this table are for coastal artillery batteries.  The range data for the 915 lbs. (415 kg) APC L4,9 shell is from two different sources, which may account for the large difference in range for only a slight change in elevation.

2) The APC L/4,9 shell had a significantly better ballistic shape than the previous ones.  It is noted as being "of longer range" than the older APC, which I take to mean that the newer projectile would have had a longer range when fired at the same elevation.
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Armor Penetration with 894 lbs. (405.5 kg) APC L3,1 Shell
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Range
Side Armor
Deck Armor
14,000 yards (12,800 m)
10.0" (254 mm)
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16,000 yards (15,000 m)
9.0" (229 mm)
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Note:  Data from "Jutland:  An Analysis of the Fighting."
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Mount / Turret Data
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Designation Two-gun Turrets
   Helgoland class (6):  Drh LC/1908
   Kaiser class (5):  Drh LC/1909
   König class (5):  Drh LC/1911
   Derfflinger class (4):  Drh LC/1912
   Hindenburg (4):  Drh LC/1913

Single Coastal Artillery Turrets
   30.5 cm L/50 Kst.Drh.L.C/37
Weight Ships:  Between 534 to 549 tons (543 to 558 mt)
Coastal Artillery:  271.9 tons (276.26 mt)
Elevation
(see Note 4)		 Ships before 1915:  -8 / +13.5
Ships after 1915:  -5.5 to +16.0 degrees
Coastal artillery:   -5 / +50 degrees
Elevation Rate Ships:  N/A
Coastal Artillery:  10 degrees per second with shell loaded
Train End Turrets:  About +150 / -150 degrees
Beam Turrets:  About +80 / -80 degrees
Coastal Artillery:  -220 / +220 degrees
Train Rate Ships:  3 degrees per second
Coastal Artillery:  4 degrees per second
Gun recoil
(see Note 5)		 36.0 in (91.5 cm)
Loading Angle Ships:  N/A
Coastal Artillery:  0 degrees
Notes:

1) The mounting weight differences were mainly the result of thicker armor used on the battleships.

2) Magazines were below shell rooms on the battleships.  On the Derfflinger class, A, B and C turrets had the magazines below the shell rooms, but D turret had the magazine above the shell room.  Derfflinger had a crew of 70 men in C mounting and probably in A and B as well while D mounting had 80 crewmen.

3) The Kaiser class were the first German battleships to have superfiring turrets.  This allowed them to have one less turret than previous classes (5 vs. 6) yet still be able to fire the same number of guns on the broadside.  The König class had all main guns on the centerline, giving them a heavier broadside than earlier ships.

4) Following the Dogger Bank action, German mountings were modified to improve flash precautions.  Double flap doors were installed at the beginning and end of the cartridge hoist and ready ammunition was removed from the gun houses.  Mountings were modified after Jutland (Skagerrak) to increase the maximum elevation from +13.5 to +16 degrees.

5) The recoil distance given above is the nominal figure.  The absolute, metal-to-metal recoil distance was 38.6 inches (98.0 cm).
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Data from
"The Battle of Jutland" by Geoffrey Bennett
"Jutland:  An Analysis of the Fighting" and "Naval Weapons of World War Two" both by John Campbell
"German Warships 1815-1945" by Erich Gröner
"Battleship Design and Development 1905-1945" by Norman Friedman
"The Big Gun:  Battleship Main Armament 1860-1945" by Peter Hodges
"Die Geschichte der deutschen Schiffsartillerie" by Paul Schmalenbach
"German Battlecruisers 1914-18" by Gary Staff
"German Warships of World War I" by John C. Taylor
"German Capital Ships of World War Two" by M.J. Whitley
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M.DV.Nr.170,54 "Merkbuch über die Munition der 30,5 cm SK L/50 der Marine-Küstenartillerie" Berlin 1940, Oberkommando der Kriegsmarine
M.DV.Nr. 234.6 "Vorläufige Beschreibung der 28 cm S.K.L/45, 28 cm S.K.L/50 und 30,5 cm S.K.L/50 in Kst.Drh.L.C.37" Berlin 1941, Oberkommando der Kriegsmarine
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Special help from Peter Lienau