Submarine AE1 Found

HMAS AE1 was an E-class submarine of the Royal Australian Navy (RAN), their first submarine. AE1 was built by Vickers Limited at Barrow-in-Furness, England, having been laid down on November 14, 1911, and launched on May 22, 1913, and commissioned into the RAN on February 28, 1914.

Accompanied by her sister AE2, under the command of Lieutenant Commander Henry Stoker, RN, AE1 departed England in March 1914, transited the Suez Canal, and reached Sydney on May 24, 1914. Although the submarines remained surfaced for almost all of the delivery voyage it was at the time the longest transit distance ever traveled by submarine.

AE1 was 181 feet long overall, with a beam of 22 feet 6 inches and a draught of 12 feet 6 inches. She displaced 750 long tons on the surface and 810 long tons submerged. The addition of watertight bulkheads strengthened the hull so she could dive to 200 feet. The complement was 34 men, officers, and ratings.

The boat had two propellers, each of which was driven by an eight-cylinder,[4] 800-brake-horsepower (600 kW) diesel engine as well as a 420-brake-horsepower (313 kW) electric motor. This gave her a speed of 15 knots, 10 knots submerged. AE1 carried 40 long tons of fuel oil for a range of 3,000 nautical miles.

At the outbreak of World War I, AE1 joined the naval forces assigned to the capture of the German Pacific colonies. With AE2, she took part in the operations leading to the occupation of German New Guinea, including the surrender of Rabaul on September 13, 1914.

On September 14, a day after the official German surrender of the colony, AE1, commanded by Lieutenant Commander Thomas Besant, left Rabaul harbor to patrol Cape Gazelle. It never returned. Five navy ships searched for two days but no wreckage or oil slick was found. Enemy action was not suspected because the only German vessel nearby at the time was a small survey ship.

In 2017, the wreck was discovered under 985 feet of water during a search off the Duke of York Islands, near the former East New Britain capital Rabaul. It was the 14th attempt to find the vessel and the resting place of its crew.

AE1’s final contact with destroyer HMAS Parramatta had placed it in the area. Mioko Island villagers at the time also spoke of seeing a “monster” or “devil fish” that appeared and quickly disappeared back into the depths. Fugro^[1] deployed its autonomous underwater vehicle (AUV) from the survey vessel, Fugro Equator.

On Wednesday, 19th December an object of interest was located and further inspection confirmed that it was AE1. Using specialized survey technology, including a multibeam echosounder mounted on the hull of Fugro Equator and its Echo Surveyor 5 AUV, Fugro scanned the seafloor to collect detailed data.

The AUV flew at a constant altitude of 35 meters, through strong undersea currents and the complex terrain of the search area, which was located between two land masses. The resulting 1-meter resolution images provided confidence that positive identification of targets could be made.

Following analysis of the data, unusual features were cataloged, assessed, and prioritized for an additional detailed investigation that included AUV and drop camera operations. The first images captured show the vessel is remarkably well preserved and apparently in one piece.

The team’s analysis of the imagery reveals that a critical ventilation valve in the hull is partially open. The valve should have been closed before diving. When the submarine dived, the partially open valve would have allowed water to flood the engine room which may have resulted in a loss of control causing the submarine to descend below its crush depth of 100m.

The resultant implosion would have killed the crew instantly. The reason why the valve is partially open is unknown. The exact location of the wreck was not announced by the Australian government at the time of discovery, in order to protect it from “unauthorized salvage attempts”. The government’s stated position is that the wreck will be treated as a war grave.