the inflation-adjusted contract value; a smaller increase than other contemporary defence projects. Characteristics The Collins class is an enlarged version of the Kockums Västergötland-class submarine. The design was referred to as the Type 471 Submarine until it was decided to name the lead boat, HMAS Collins, after RAN Vice Admiral Sir John Augustine Collins. The names of the six submarines were first announced during Collins laying down ceremony: Collins, Farncomb, Waller, Dechaineux, Sheean, and Rankin; all named after Australian naval personnel who distinguished themselves during World War II. The Collins-class submarines are classified by the RAN as SSGs, or guided missile carrying submarines, although some defence industry websites refer to the boats as hunter-killer submarines, or SSKs. At in length, with a beam of and a waterline depth of , the six boats were the largest conventionally powered submarines in the world at the time of their commissioning. The submarines are single-hulled, and have two continuous decks. Each boat displaces when surfaced, and when submerged. The depth that the submarines can dive to is classified. Following the near-loss of Dechaineux in 2003 when a seawater hose burst during a deep dive, the diving depth was reduced. The hull is constructed from a high-tensile micro-alloy steel, developed by Swedish steel manufacturer SSAB, and improved by BHP of Australia, which was lighter and easier to weld than the HY-80 or HY-100 nickel-alloy steel used in contemporary submarine construction projects, while providing better results in explosion bulge testing. The submarines are covered in a skin of anechoic tiles to minimise detection by sonar: Collins was retrofitted with the tiles after the standard sonar signature of the submarine had been established, while the other five boats were covered during construction. These tiles were developed by the Australian Defence Science and Technology Organisation (DSTO) as the United States and United Kingdom would not share their information on the tiles used on their nuclear submarines, Australian researchers had to develop the tiles from scratch. The tiles were moulded in the shape of the hull, and are secured by a commercial adhesive normally used to fix cat's eyes to road surfaces: although British and American submarines are often seen with missing tiles, as of March 2007, none have been lost from a Collins-class boat. Armament The Collins-class submarines are armed with six torpedo tubes, and carry a standard payload of 22 torpedoes. Originally, the payload was a