The Pattern 1905 was similar in construction to the Vickers 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.
