During World War I, the only underwater detection device in use was the hydrophone – a passive listening set. In June 1917, the British Admiralty and the Royal Navy embarked upon an intensive investigation to improve the efficiency of underwater detection equipment both for harbour defence and anti-submarine operations at sea. The Allied Submarine Detection Investigation Committee (acronym ASDIC), whose work was highly classified for security purposes, was tasked with the work. By 1923, the first Asdic set was available for ship fitting and personnel training.
Introduction of ASDIC
The Asdic set was basically an underwater sound projector with the ability to obtain echoes from underwater objects. The oscillator (known as a transducer) used to make the sound was also able to pick up noise generated by an underwater object.
The first RAN officers to be trained as Anti-Submarine (A/S) specialists trained in England in 1924. Subsequent RAN specialist A/S Officers also trained in England, including during and after WWII. During the pre-WWII years, Asdic equipment and tactics were so highly classified that such knowledge could not be imparted to Reserve officers.
At an Imperial Conference held in London in 1937, the various categories of Naval training required to provide manpower for the outbreak of a major war were analysed and the Dominions agreed to provide trained Reserve personnel, both officers and sailors, for anti-submarine operations, including Harbour Defence.
Rushcutters Bay Anti-Submarine School
The RAN Reserve Depot at Rushcutters Bay was selected as the site for building a specialised school and South Head, an army establishment, was chosen as the site for a control station for underwater harbour defence equipment. In addition to normal classrooms, the two-storey building was designed to replicate the fitting of Asdic equipment in ships. This required the installation of dome lowering equipment on the upper floor, as fitted within the hull of a ship, and a hole was cut through the upper floor so that the dome could raised and lowered as in a ship.
Lieutenant Commander H. M. Newcomb RN, from the staff of the A/S School in England, was appointed to supervise the fitting out of the Australian School, and to conduct training. In November 1938, Acting Commander Newcomb arrived in Sydney to take over control of the school building which had largely been completed in October. He was assisted by three Petty Officer Submarine Detector Instructors (PO SDI), three Leading Seamen Higher Submarine Detectors (LS HSD) on loan from the RN, and six RAN Able Seamen Submarine Detectors (AB SD).
HMA Anti-Submarine School was commissioned on 13 February, 1939, under the command of Commander Newcomb RN, and was a separate element within the RAN Reserve Depot, which was under separate command. There was no residential accommodation for officers or sailors within the Depot; this remained a continuing challenge for them all for most of the War. The School was protected by non-Naval security guards.
At the end of 1938, there had been a recruiting drive for volunteers to join the Naval reserve as members of the Anti-Submarine Branch. A Naval Selection Board was established to interview applicants and to select those considered suitable as commissioned officers. Interviews were conducted in January and February 1939 and 66 officers and about 30 sailors were selected for training. Aural acuity was an essential requirement for all candidates but testing in those days was primitive. The basic test required a person with a violin to stand behind a candidate who was required to state whether a musical note was higher, lower or the same as the note which preceded it.
Training began in February 1939 when the installation of Asdic Type 123 was completed. In the initial stages, there were no procedure or attack teachers fitted and those aspects of training were undertaken in the destroyer and local defence vessel attached to the school for sea training. A Type 123 Attack Teacher Table was in operation by June 1939. Lack of a submarine training target was a severe deficiency, which was temporarily alleviated by the visit of HM Submarine Phoenix from the Royal Navy’s China Station.
By the outbreak of war in September 1939, 62 officers of the original 66 had qualified as A/SCOs and 32 sailors had qualified as SDs. The Royal Navy was offered a supply of 12 A/SCOs and 12 SD Sailors every two months. The Royal Navy responded by asking for as many A/SCOs as possible and for 20 SDs each month. To meet this requirement, there was an immediate increase in the training output to 72 officers and 240 sailors per year. RAN requirements also had to be met but these were relatively small at this stage. This training load required a considerable increase in the instructional staff, classroom space and mechanical gear. The eastern wing of the school had to be extended to accommodate classrooms.