Shipyard
A shipyard (also called a dockyard) is a place where ships are built and repaired. These can be yachts, military vessels, cruise liners or other cargo or passenger ships. Dockyards are sometimes more associated with maintenance and basing activities than shipyards, which are sometimes associated more with initial construction. The terms are routinely used interchangeably, in part because the evolution of dockyards and shipyards has often caused them to change or merge roles.
Royal Navy Dockyard
Throughout its history, the Royal Navy has (when necessary) made extensive use of private shipyards and dockyards, both at home and abroad, and continues to do so. Nevertheless, since the reign of Henry VIII it has also made a point of establishing and maintaining its own dockyards. These Royal Navy dockyards have always had a dual function: shipbuilding and ship repair/maintenance; historically, most yards provided for both, but some specialized in one or the other.
Dockyards were often built around a number of docks and slips. Traditionally, slipways were used for shipbuilding, and dry docks (also called graving docks) for maintenance; (dry docks were also sometimes used for building, particularly pre-1760 and post-1880). Regular hull maintenance was important: in the age of sail, a ship's wooden hull would be comprehensively inspected every 2–3 years, and its copper sheeting replaced every 5. Dry docks were invariably the most expensive component of any dockyard (until the advent of marine nuclear facilities). Where there was no nearby dock available (as was often the case at the overseas yards) ships would sometimes be careened (beached at high tide) to enable necessary work to be done. In the age of sail, wharves and capstan-houses were often built for the purpose of careening at yards with no dock: a system of pulleys and ropes, attached to the masthead, would be used to heel the ship over giving access to the hull.