3 September 1939
When the Australian Government declared war on 3 September 1939, the Royal Australian Navy (RAN) had 13 operational ships:
- 2 heavy cruisers
- 4 light cruisers
- 5 First World War–vintage destroyers
- 2 sloops.
Four new ships were still being built:
- 2 Tribal-class destroyers
- 2 sloops.
In May that year, the three defence chiefs of staff had accepted British assurances that they would send a fleet to defend Singapore. They were also assured that the island could hold out against the Japanese. In spite of this, it was recommended Australia prepare for medium-scale attacks rather than light raids.
Though Australia was at war with Germany as of 3 September, the central problem for defence planning was of Japanese intentions. At that time, Japan was neutral. However, the absence of British forces in south-east Asia would leave Australian trade and territory vulnerable to attack if this changed.
The RAN commenced operations immediately at the outset of war. The following ships were fully worked up:
- 3 cruisers
- 3 destroyers
- 2 sloops.
The remainder of the fleet was in commission, or almost there. Some ships were still being built, but were provisioned for war. The reserves had been called up in September 1939, doubling the RAN’s permanent force from 5,440 to 10,259 personnel.
The RAN’s major focus would be the protection of shipping, mostly via convoy operations. They acted as naval escorts accompanying convoys of merchant ships.
Fishing trawlers were converted into minesweepers. This expansion of the minesweeping service made clear the kind of war the government expected to fight. Minesweeping groups were set up in:
- Sydney
- Melbourne
- Fremantle
- Brisbane
- Newcastle.
RAN's primary role was the defence of trade and the safe arrival of troops and war materiel wherever needed. This was demonstrated by:
- the focus on minesweeping craft
- the improvement of Australia’s anti-submarine warfare capability
- the activation of control of shipping arrangements and port defences.