[Specification and arrangement drawings (14) of twin-screw, iron-clad frigate "Superb" renamed "Alexandra" / Admiralty (& Chatham Dockyard). 1872-1877. 14 sheets on roll, scales various. Comprise specification (12p.) (1872); drawing showing 'places in which the Watertight Bulkheads & Flats would be pierced ...'; 'arrangement of watertight compartments, watertight-doors, sluices-valves &c', bearing numerous signatures (1877 Apr 21); and 2 sets of copy plans, ( 6 per set), of hold and sections, main deck, upper deck, profile, lower deck, and poop, battery deck and forecastle]