Gjessing calculates co-operation between the Royal Navy and the RAN in equipment procurement and design. Great assistance was given by the Admiralty in the implementation of the Australian Naval Air Arm; the creation of the latter was unthinkable without the former. Loans of vessels from one service to another took place, with most of these being from the Royal Navy to the RAN. Although Australia reached agreement with the USA on standardisation of military equipment, this had little effect upon Anglo-Australian naval co-operation in the procurement of major vessels. Equipment design co-operation between the RAN and the Royal Navy was typified by the Ikara ASW missile system, a weapon system fitted to both nations’ vessels. When Australia implemented a submarine capability of its own, primarily due to dwindling British resources, British submarines were chosen. The RAN also accepted Admiralty support following the loss of the destroyer HMAS Voyager in 1964.