captured and used by the Red Army in the Russian Civil War. Four were retained by Estonian forces, and two by Latvia. Mark V* The Mark V* was a version with a stretched hull, lengthening it by . It had a larger cupola on the roof and doors in the side of the hull (previous versions had small hatches under the sponsons of females or small doors in the rear of the sponson for males, along with a small hatch in the rear). The extra section was also designed to house a squad of infantry. The weight was 33 tons. Of orders for 500 Males and 200 Females, 579 had been built by the Armistice – the order was completed by Metropolitan Carriage in March 1919. Mark V** Because the Mark V* had been lengthened, its original length-width ratio had been spoiled. Lateral forces in a turn now became unacceptably high, causing thrown tracks and an enormous turning circle. Therefore, Major Wilson redesigned the track in May 1918, with a stronger curve to the lower run reducing ground contact and the tracks widened to . The Mark V engine was bored out to give and was sat further back in the hull. The cabin for the driver was combined with the commander's cabin; there now was a separate machine gun position in the back. Of a revised order for 700 tanks (150 Females and 550 Males), only 25 were built and only one of those by the end of 1918. Mark VI The Mark VI was one of a pair of related projects to develop the tank initiated in late 1916. The Mark V would be the application of as many advanced features as could be managed on the Mark I hull design and the Mark VI would be a complete break with the Mark I hull. The Mark V would not be built as such, because of the delays with the Mark IV and it would be a different Mark V that was built. The Mark VI project design had a completely new hull – taller and with rounded track paths. The single main gun was in the front of the hull. It did not progress past the stage of a wooden mock-up; the project was cancelled in December 1917 in order that a tank co-developed with the US (the Mark VIII) could go forward. Mark VII Mark Knothe,