Used on the armored cruisers built in the 1890s and early 1900s. Most ships had single or twin turrets mounted on the bow and stern with the Scharnhorst class having an additional four single guns mounted amidships in casemates.
There were three versions of this weapon. The C/97 was used on the Victoria Louise class and was constructed of two layers of hoops and a cylindro-prismatic breech wedge. The C/01 was designed for twin turrets that were used on the later armored cruisers and had an extra layer of hoops on the rear of the gun. The C/04 version was similar to the C/01 but was designed for casemate mountings and did not have the extra layer of hoops.
Eight guns removed from the Victoria Louise class were used on the Belgian coast in the Freya and Hertha batteries (four guns each). In May 1917, one gun removed from the Armored Cruiser Roon was emplaced at Cape Helles, Turkey, where it was used to harass the British ships seen at Kephalo and Aliki.
Actual bore diameter was 20.93 cm (8.24").
| Designation | 21 cm/40 (8.27") SK L/40 C/97
21 cm/40 (8.27") SK L/40 C/01 21 cm/40 (8.27") SK L/40 C/04 |
|---|---|
| Ship Class Used On | C/97: Victoria Louise class
C/01: Prinz Adalbert, Roon and Scharnhorst (1907) classes C/04: Scharnhorst (1907) class |
| Date Of Design | 1897 - 1904 |
| Date In Service | 1898 - 1905 |
| Gun Weight | C/97: 36,376 lbs. (16,500 kg)
C/01: 44,137 lbs. (20,020 kg) C/04: 41,667 lbs. (18,900 kg) |
| Gun Length oa | 331 in (8.400 m) |
| Bore Length | 307 in (7.801 m to 7.811 m) |
| Rifling Length | N/A |
| Grooves | N/A |
| Lands | N/A |
| Twist | N/A |
| Chamber Volume | 3,034 in3 (49.7 dm3) |
| Rate Of Fire | 4 - 5 rounds per minute |
| Type | Separate |
|---|---|
| Projectile Types and Weights | Most, if not all, of the projectiles used for the 21 cm SK L/40 guns were also used by the 21 cm SK L/45 guns. See that datapage for information and diagrams of shell types. |
| Propellant Charge | 65.6 lbs. (29.8 kg) RP C/00 or RP C/06 |
| Muzzle Velocity | AP L/2,9 and HE L/3,1: 2,559 fps (780 mps)
HE L/4,3: N/A |
| Working Pressure | N/A |
| Approximate Barrel Life | N/A |
| Ammunition stowage per gun | Victoria Louise: 58 rounds
Prinz Adalbert: 85 rounds Roon: 95 rounds Scharnhorst: 87.5 rounds |
| Elevation | Distance |
|---|---|
| 16 degrees
(max. elevation of casemates) |
13,560 yards (12,400 m) |
| 30 degrees | 17,830 yards (16,300 m) |
| Designation | Two-gun turrets
Prinz Adalbert (2), Roon (2) and Scharnhorst (2): DrL C/01 1 2 |
|---|---|
| Weight | TL C/97: 88.6 tons (90 mt)
DrL C/01: 167.3 - 171.3 tons (170 - 174 mt) MPL C/04: N/A |
| Elevation | TL C/97: -5 / +30 degrees
DrL C/01: -5 / +30 degrees MPL C/04: -5 / +16 degrees |
| Elevation Rate | DrL C/01: 5.0 degrees per second
Others: N/A |
| Train | about +150 / -150 degrees |
| Train Rate | DrL C/01: 5.4 degrees per second
MPL C/04: 4.5 degrees per second Others: N/A |
| Gun recoil | N/A |
| Loading Angle | N/A |
- ^The DrL C/01 was hydraulically powered and had pusher hoists.
- ^DrL C/01 face and sides were 6.7 inches (17 cm) except Roon 5.9 inches (15 cm) and roof was 1.2 inches (3 cm).
- ^The TL C/97 mounting was hydraulically powered with manual loading.
- ^TL C/97 shield was 0.3 to 0.4 inches (8 to 10 mm).
- ^MPL C/04 was electrically trained and manually elevated and loaded.
- ^MPL C/04 shield was 1.6 to 5.9 inches (4 to 15 cm) thick.
"Big Gun Monitors: The History of the Design, Construction and Operation of the Royal Navy's Monitors" by Ian Buxton
"Naval Weapons of World War One" by Norman Friedman
"German Warships 1815-1945: Volume One: Major Surface Vessels" by Erich Gröner
"Die deutsche Flotte, Zweibrücken 1901" by Ernst Graf Reventlow
"Taschenbuch der Kriegsflotten 1905" by Bruno Weyer (Kapitänleutnant a.D.)
"The Great War: The Standard History of the All Europe Conflict (volume four)" edited by H. W. Wilson and J. A. Hammerton
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"Diagrams of Great War - German Naval Guns; Shells & Explosives; Fuses & Exploders" by The Royal Laboratory Woolwich 1921-22
"Munitionsvorschriften für die Kriegsmarine - Panzersprenggranaten (Psgr)" M.Dv. Nr. 190,1A2 by Oberkommando der Kriegsmarine
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Special help from Rainer Troendle and Thorsten Wahl
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Tony DiGiulian's personal files
14 October 2006 - Benchmark
25 February 2009 - Added comment about gun from Roon
13 September 2010 - Corrected photograph caption
10 January 2011 - Added gun details kindly provided by Rainer Troendle
05 December 2012 - Added gun, projectile and coastal artillery details
06 June 2015 - Minor additions
29 July 2018 - Converted to HTML 5 standard, minor correction
19 February 2019 - Added ammunition information from M.Dv. Nr. 190,1A2
18 November 2022 - Added information and sketches on World War I coastal artillery projectiles
16 August 2024 - Minor changes