Scale 1:48. Plan shows the port inboard profile, looking from starboard, plan views of the superstructure top, bridge top and an internal plan view above the flats, as fitted of the U class submarines Unbroken (1941), Unison (1941), United (1941), Unruffled (1941), Unrivalled (1941), Unshaken (1941), P42 (1942) and Unseen (1942). A Vickers Armstrong builder's stamp, dated 15 March 1944 is printed on the drawing. A Vickers Armstrong Principal Ship Overseer's stamp, dated 20 March 1944 is also printed on the plan.