Ships Cover for the River class destroyers (1903-1905). The documentation includes very detailed analysis and discussions relating to the requirements of a new destroyer design, comparisons of existing British designs with the new type as well as foreign contemporaries, a number of alternate design proposals, details of ships fittings, highly detailed information on comtemporary foreign destroyers with the greatest emphasis placed on analysis of the German S90 class, details of Imperial German Navy destroyer flotilla organisation, training, equipment and tactics, records of alterations made to the design prior to construction, copies of tenders and correspondence with the main contractors, and cost estimates. Of particular interest is a significant amount of paperwork towards the end of the Cover concerning the building of vessels to be run on oil-fuel. The reports and precis of discussions are very detailed and wide-ranging, and include analysis of the oil-fuel wing compartments of the German battleship SMS Kaiser Friedrich III (1896) and the riveting experiments trialled for oil-fuel storage tanks aboard the -at that time incomplete- HMS Black Prince (1904). There is also a very detailed report on the examination of the oil-fuel burning system aboard the merchant vessel Mariposa (1891). The earliest papers date from January 1894 and the last from January 1905. Ships Cover 200 continues some of the design discussions initiated in this Cover, but with a view to improving on the River class.