The prototype Mark I, ready in December 1915, was called "Mother" (previous names having been "The Wilson Machine", "Big Willie", and "His Majesty's Land Ship Centipede").
Prototypen af Mark I, som var klar i december 1915, blev kaldt "Mother" (tidligere navne havde været "The Wilson Machine", "Big Willie" og "His Majesty's Land Ship Centipede").