| Origin: | Germany |
| Type: | Naval gun Coast-defense gun |
| Is Ranged: | YES |
| Is Artillery: | YES |
| Service: | 1938–1953 |
| Wars: | World War II |
| Design Date: | 1934 |
| Weight: | 53250kg (117,400lb) |
| Length: | 15.4m (50.5feet) 54.5 Caliber |
| Part Length: | 14.5m (47.6feet) (bore length) |
| Cartridge: | Separate-loading, bagged charge |
| Caliber: | 283mm |
| Velocity: | 890m/s |
| Max Range: | 40930m (134,290feet) at 40°[1] |
| Elevation: | –8° to +40° |
The German 28 cm SK C/34[2] naval gun was a 283 mm 54.5-caliber built-up gun designed in 1934 used on the and for the planned Landkreuzer P. 1000 Ratte super-heavy tank.
The previous 28 cm gun was the SK C/28 used on the . The Scharnhorst class received an improved version of the SK C/28 which had a longer barrel—the SK C/34.
The 283 mm SK C/34 gun was relatively fast loading, compared with other armament of this size. It could deliver a shot every 17 seconds. The ballistic properties of the guns made them effective against the new French, which had an armored belt 225–283 mm, barbettes of 310–340 mm, at standard fighting distances.
An improved version of the gun was planned to be mounted on the Netherlands' Design 1047 battlecruisers, but the ships were never begun due to the start of the Second World War.[3]
When 's turrets were removed for re-arming and upgunning to 38 cm in 1942–43, her guns were redeployed for coast defence at Fjell festning ´(11.MAA 504) in Sotra, Norway (Bruno turret), at Batterie Oerlandat (4.MAA 507) in Austrått, Norway (Cesar turret), and guns from Anton turret were installed at Battery Rozenburg in the Netherlands.[4]
| +Effectiveness of the guns against armor in different situations | ||||||
| Distance | 0 | 7900m (25,900feet) | 15100m (49,500feet) | 18288m (60,000feet) | 27432m (90,000feet) | |
|---|---|---|---|---|---|---|
| Shooting angle[deg] | 0 | 3.3 | 7.4 | 9.7 | 18.7 | |
| Shell hitting angle[deg] | 0 | 4.4 | 10.3 | 15.2 | 30.2 | |
| Shell velocity at target | 890m/s | 693m/s | 552m/s | 496m/s | 420m/s | |
| Side armor belt penetration | 604mm | 460mm | 335mm | 291mm | 205mm | |
| Deck armor penetration | - | 19mm | 41mm | 48mm | 76mm |
Characteristics of SK C/28 and SK C/34 283 mm shells:
| Gun type | Shell type | Length (calibers) | Total weight | |
|---|---|---|---|---|
| SK C/28 | Armor-piercing | 3.7 | 300kg (700lb) | |
| Semi-armor-piercing | 4.2 | 300kg (700lb) | ||
| Igniting | 4.2 | 300kg (700lb) | ||
| SK C/34 | Armor-piercing | 4.4 | 336kg (741lb) | |
| Semi-armorpiercing | 4.4 | 316kg (697lb) | ||
| Igniting | 4.5 | 315kg (694lb) |