The records were transferred from the Admiralty between 1961 and 1977 and are known by the Public Record Office class, ADM/168. They consist of technical specifications for naval ships built in commercial yards, giving details of dimensions, materials and qualities of the ships to be built under contract. They are similar to the Ships' Specifications (entry no.7, ADM/170), but in addition have a preamble and final section dealing with the dates for the payment of instalments and with delivery. Prices, however, are usually not entered; the evidence to be gained from these documents is, therefore, of a technical rather than a financial nature. Each volume is for a specific vessel but the technical details given can normally be taken as applying to an entire class of ship. The records cover the period from the middle of the eighteenth century to the end of the Second World War. Until 1780 the contracts are in manuscript form; from that date printed books were used with blank spaces for the insertion of the details. From the middle of the nineteenth century volumes were printed individually. The Admiralty collection of ships' plans, held in the Draught Room, occasionally includes material similar to that described here, together with occasional letters and memoranda concerned with design or building. (Department of Ships: ADM/168: 152ft: 46m) The records were transferred from the Admiralty between 1961 and 1977 and are known by their Public Record Office class, ADM/170. They consist of technical specifications for naval ships built in the Royal dockyards, and contain details of the quantities and qualities of materials to be used and the dimensions of the ship's structure. They are similar in content to the Ships' Contracts (entry no.6, ADM/168), except that they omit the contract preamble and closing sections. The series begins with a listing of the scantlings of the 1719, 1741 and 1745 Establishments and extends to the end of the Second World War. Until the mid-nineteenth century these documents are in manuscript; thereafter they were individually printed. The Admiralty collection of ships' plans, held in the Draught Room, occasionally includes specifications similar to those described here, together with occasional letters and memoranda concerned with design or building.