Why the rhomboid tank and the name "tank" emerged

The rhomboid form offered dependable movement across difficult ground, the central operational demand of trench warfare. The Army intervened once the experiments appeared likely to succeed and sought to transfer personnel along with the project. D'Eyncourt declined to follow, returning his attention to battleship construction after the short landship effort. In December 1915 the vehicles adopted the deliberately bland code name "tank," while the organization evolved from the Director of Naval Construction's committee into the Tank Supply Committee. Engineering, operational testing, secrecy, and bureaucratic ownership all shaped the first tanks.