Modern shipbuilding makes considerable use of prefabricated sections. Entire multi-deck segments of the hull or superstructure will be built elsewhere in the yard, transported to the building dock or slipway, then lifted into place. This is known as "block construction". The most modern shipyards pre-install equipment, pipes, electrical cables, and any other components within the blocks, to minimize the effort needed to assemble or install components deep within the hull once it is welded together. This was first introduced by Alstom Chantiers de l’Atlantique when they built the largest Ocean Liner in the world Cunard’s RMS Queen Mary 2.
Ship design work, also called naval architecture, may be conducted using a ship model basin. Modern ships, since roughly 1940, have been produced almost exclusively of welded steel. Early welded steel ships used steels with inadequate fracture toughness, which resulted in some ships suffering catastrophic brittle fracture structural cracks (see problems of the Liberty ship). Since roughly 1950, specialized steels such as ABS Steels with good properties for ship construction have been used. Although it is commonly accepted that modern steel has eliminated brittle fracture in ships, some controversy still exists. Brittle fracture of modern vessels continues to occur from time to time as the use of grade A and grade B steel of unknown toughness or fracture appearance transition temperature (FATT) in way of ships’ side shells can be less than adequate for all ambient conditions.Construction of prefabricated module blocks of HMS Dauntless at BAE’s Portsmouth Shipyard.