Updated 21 December 2011

Battleship Helgoland in 1915
The last class of German battleships with a hexagonal layout and no superfiring turrets
Photograph copyrighted by HDW

30.5 cm/50 (12") wing turret on Battleship Ostfriesland
Secondary guns are 15 cm/45
Bain News Service Photograph
Library of Congress Photograph ID LC-DIG-ggbain-17760

30.5 cm guns on SMS Thüringen

Grosser Kurfürst in November 1918
First class of German Capital ships with all turrets on the center line

30.5 cm/50 (12") guns on Battleship Kaiser
Bain News Service Photograph
Library of Congress Photograph ID LC-DIG-ggbain-25469

Unexploded 30.5 cm (12") APC shell that struck HMS Defender during the Jutland (Skagerrak) Battle
This was fired from the German 3rd Squadron and ricocheted off the water before hitting Defender
Note that shell has lost both ballistic cap and driving bands

Comparison of 30.5 cm SK L/50 and 38 cm SK L/45
The propellant charges are only for the 38 cm
The sailor is holding a meter stick for comparison purposes

The following sketches are from this document

APC L/3,4 - Psgr. L/3,4

HE L/3,8 projectile with base fuze - Spr.gr. L/3,8 Bdz

HE L/3,6 projectile with base and nose fuzes - Spr.gr. L/3,6 Bdz u. Kz (mhb)

Base fuze for Psgr. L/3,4 and Spr.gr. L/3,8 Bdz

Base Fuze for Spr.gr. L/3,6 Bdz u. Kz (mhb)

Nose Fuze for Spr.gr. L/3,6 Bdz u. Kz (mhb)

Special Base Fuze

Main Charge - 30,5 cm Hauptkartusche

   Fore Charge - 30,5 cm Vorkartusche

27 December 2008 - Benchmark
18 November 2010 - Corrected typographical error, modified some picture captions for clarity
21 December 2011 - Added picture of shell that hit HMS Defender