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 was 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.