Scale 1:12 and 1:1. An ozatrace copy of a plan showing the modifications made to the layout of the computer room on the sonar trials ship Matapan (1945). Matapan was originally a Battle class destroyer that was converted into a sonar trials ship in 1971. This drawing is noted as Sheet 2 of 3 and was drawn by R. Nelson [Draughtsman at Portsmouth Dockyard flourishing 1974].