3dprinted in Grey
Size: 1.24" (31.4mm) long
Initial production of the Mark I was to be by Fosters and Metropolitan: 25 from Fosters and 75 from Metropolitan, which had greater capacity in Wednesbury at the Old Park site of the Patent Shaft Company, a subsidiary of the Metropolitan. Metropolitan also received an order for a further 50 so that the Army would be able to raise six tank companies of 25 tanks each and set up further production under their Oldbury Wagon and Carriage Company. As there were not enough 6-pounder guns available for all 150 tanks, it was decided to equip half of them with just machine guns. A new sponson design with two Vickers machine guns in rotating shields was produced.
Later in the war when newer tanks came into use some Mark Is were converted to be used for carrying supplies. A few Female Mark Is were used as mobile wireless stations by installation of a wireless transmitter. The radio could only be operated once the tank had stopped and erected a very tall mast that carried the aerial array
(More on Wiki HERE)