Ships Cover for the Challenger class second class protected cruisers HMS Challenger (1902) and HMS Encounter (1902). The documentation mainly comprises the initial correspondence relating to this variant of the Highflyer class design, estimated and actual costs of building and fitting out, statements of dimensions and estimates of weights, details of boilers and machinery, details of gun and torpedo armament and their respective ammunition allowance, ships fittings and equipment, alterations proposed and carried out, schemes of complement, details of tenders and correspondence with contractors for machinery, stability calculations, reports of steam and manoeuvreing trials, and vessel condition reports. The earliest papers date from August 1896 with the authorisation of the Highflyer class ships, and the last from August 1917, by which point Challenger was engaged in second-line duties and Encounter was a depot ship in Australian waters.