We’re now on the aft section of the ship, known as the quarterdeck. This is where loaded depth charges were stockpiled ready to be launched – some on the rails, and others on the throwers.

Surrenders. Only 2 ships remain in the world where a World War 2 surrender was signed on board. The most famous is USS Missouri, located at Pearl Harbour, on which the main Japanese surrender was signed in Tokyo Harbour in September, 1945.

Diamantina sailed to Moila Point, the southernmost tip of Bougainville, to collect the Japanese Lieutenant General Kanda, his chief of staff and the commander of the region’s Japanese Naval forces.  On the morning of 8 September, 1945, on the quarterdeck, the Japanese officers handed over their swords.

The Japanese surrender party was held in the sick berth while Diamantina sailed to Torokina where they disembarked to complete the signing ceremonies ashore. The quarterdeck of Diamantina was used for two more surrender ceremonies at Nauru and Ocean Islands. The signing at Ocean Island on 1 October was the final surrender ceremony of the war.

Port and starboard 40 mm Bofors Anti-aircraft Guns. Firing a 2 pound (0.9 kg) projectile, these were standard anti-aircraft weapons during the latter part of World War 2 and can still be found in use today. Configurations included single, double and quadruple mounts, both manually and power-operated.

Diamantina had 3 manual, single mounts.

The Bofors fired a 40 mm explosive shell at a rate of 120 rounds per minute. A complete round weighed 4.9 pounds (2.2 kg). Ammunition was loaded in clips of four rounds, weighing 8.8 kg. Therefore, a new clip had to be loaded every two seconds!!.

Port and starboard depth charge throwers. Diamantina had four throwers, two on each side. Each thrower had a ready rack holding five charges ready for use.

Depth charges were a drum weighing 420 lbs (191 kg) and containing 290 pound (130 kg) of explosive (Amatol) used to destroy submarines. Before being used, the detonator was set to explode the depth charge at a certain depth, the information being relayed from the ASDIC Office. The throwers projected depth charges about 40 m out to the side of the ship, at different angles, while other charges were released over the stern. Depth charges were released in a “pattern”, with the intention that the combined explosion would damage or destroy the submarine’s hull.

Each depth charge rail could hold 12 depth charges. At the same time the throwers released their depth charges, others were allowed to roll over the stern of the ship from the rails. It was important that the ship maintained adequate speed to ensure that it was clear of the area when the depth charges exploded.

A depth charge had to explode within about 6 m of a submarine to sink it and about 12 m from the submarine to damage it sufficiently to bring the submarine to the surface.It is suggested that less than 5% of all depth charges used resulted in a destroyed submarine.