The documents, from Admiralty records, consist of six profile plans of slips and docks at Pembroke, 1860 to 1863, showing in longitudinal section the longest ships which could be built or repaired in each. There is also a detailed plan of the yard in 1866 which shows the sources of water supply.

Administrative / biographical background
The dockyard at Pembroke was established in 1815 when equipment and personnel were moved from Milford Haven, where there had been a small building yard administered by the Navy Board since 1800. The yard was reduced to a naval store and fuel depot in 1930.