203 mm 50 caliber Pattern 1905

Vickers 203 mm 50 caliber Pattern 1905
A Pattern 1905 gun in Suomenlinna fortress, Helsinki. Manufactured by the Obukhov factory in 1909.
Type	Naval gun Coastal artillery Railway artillery
Place of origin	Great Britain
Service history
In service	1905-1945
Used by	Russian Empire Soviet Union
Wars	World War I Russian Civil War Winter War World War II
Production history
Designer	Vickers
Designed	1905
Manufacturer	Obukhov State Plant
Produced	1905
Specifications
Weight	14.4 t (15.9 short tons)
Length	10.16 m (33 ft 4 in) 50 caliber
Barrel length	9.95 m (32 ft 8 in)
Shell	Separate loading bagged charge and projectile
Shell weight	112–139 kg (247–306 lb)
Calibre	203 mm (8.0 in)
Breech	Welin breech block
Elevation	Casemates: -5° to +25° Turrets: -5° to +25° Open mounts: -5° to +30°
Rate of fire	3-4 rpm
Muzzle velocity	792 m/s (2,600 ft/s)
Maximum firing range	15.7 km (9.8 mi) at +25°

The 203 mm 50 caliber Pattern 1905 was a Russian naval gun developed by Vickers for export in the years before World War I that armed a variety of warships of the Imperial Russian Navy. Guns salvaged from scrapped ships found a second life as coastal artillery, railway artillery and aboard river monitors during the Russian Civil War. By 1941 it was estimated there were 36 coastal defense guns and two railroad mounts remaining. During the 1930's a number were relined down to 180 mm (7.1 in) and re-designated the 180mm Pattern 1931-1933. These guns were used aboard Kirov-class cruisers or as coastal artillery and railway artillery.

The Pattern 1905 began life as a Vickers design for export customers called the Mk B and Mk C. These guns did not serve aboard ships of the Royal Navy because they had standardized on 7.5 in (190 mm) guns. The Pattern 1905 was also produced under license at the Obukhov State Plant in St. Petersburg, Russia.

The Pattern 1905 was similar in construction to the Vickers 10 in (250 mm) 50 caliber guns produced by Vickers for the Imperial Russian Navy. The Pattern 1905 was a built-up gun which consisted of an A tube, two layers of reinforcing tubes and a Welin breech block. The initial order for eight Vickers Mk B guns served aboard the Russian cruiser Rurik in four twin turrets. Later another thirty-four Mk C guns were ordered from Vickers in 1914. A further nineteen were produced by Obhukov in 1914 to replace worn barrels with only minor differences between the series.

The 203mm 50 caliber Pattern 1905 guns armed armored cruisers, river monitors and pre-dreadnought battleships of the Imperial Russian Navy and Soviet Navy built or refit between 1905-1930.