The BL 8-inch howitzer Marks VI, VII and VIII (6, 7 and 8) were a series of British artillery siege howitzers on mobile carriages of a new design introduced in World War I. They were designed by Vickers in Britain and produced by all four British artillery manufacturers, but mainly by Armstrong, and one American company. They were the equivalents of the German 21 cm Morser 16 and in British service were used similarly to the BL 9.2-inch howitzer, but were quicker to manufacture, and more mobile. They delivered a 200 lb shell to 12,300 yards. They had limited service in the British Army in World War II before being converted to the new 7.2-inch calibre. They also equipped a small number of Australian and Canadian batteries in World War I and by the US Army in that war. They were used in sma