Scale: 1:48. Plan showing the body plan with half stern board outline, sheer lines with alterations to the gunports, and longitudinal half-breadth for building Mersey (1858) and Orlando (1858), both 40-gun screw frigates. Copies were made at Chatham and Pembroke Dockyards.

The gunports in red relate to Mersey as a 40-gun ship, the ports in black are as originally designed for a 36-gun ship, and those in pencil are for Orlando. At some point the plan may been proposed for a 40 and 50-gun ship judging by the pencil annotation under the ink title.

Signed by Charles Wood and M. F. F. Bukeley [both unknown], Baldwin Wake Walker [Surveyor of the Navy, 1848-1860], John Edye [Assistant Surveyor] and Isaac Watts [Assistant Surveyor]. The plan is also Initialled J. E. or J. L. [James Luke, Inspecting Officer].