Scale 1:48. Plan shows the starboard profile looking from port, as fitted of the T class submarines Thrasher (1940), Thorn (1941) and Tempest (1941). There is a Cammell Laird builder's stamp dated 24 March 1942 printed on the plan. A Principal Ship Overseer's stamp, dated 25 March 1942 is also printed on the drawing. The plan shows alterations in red ink specifically for Thorn. The drawing also includes alterations in blue ink specifically for Thrasher at Chatham dated April 1943. This plan is noted as Sheet 1 of 2.