946 – The Tragedy of Exercise Tiger

Slapton Sands in South Devon, with its unspoiled gravel beach fronting a shallow freshwater ley and backed by grassy slopes, seemed perfect to the American forces to simulate practice landings for the launch of Operation Overlord on 6 June 1944, the D-Day landings in Utah Beach, France.

Exercise Tiger, under the command of the US Navy Admiral Don P. Moon, was one of several assault rehearsals conducted at Slapton Sands. So vital was the exercise that the commanders had ordered the use of live naval and artillery ammunition to make the exercise as real as possible to accustom the soldiers to what they would experience.

This exercise also turned out to be one of the great tragedies of World War II. Hundreds of American soldiers and sailors died needlessly due to confusion and incompetence. It was one of the military’s best-kept secrets until it was revealed to the world almost 40 years later.

The exercise was conducted between 22 and 30 April 1944 and commenced with the marshalling and embarking of the troops to convoys of tank landing ships (Landing Ships, Tank or LSTs, flat-bottomed four-and-a-half-thousand-ton assault ships capable of carrying several hundred men, lorries and tanks) off the coast of south-west England. The first assault landings were made on the morning of the 27 April, following a bombardment and were continued throughout the day. A follow-up convoy of eight LSTs was expected later that night and it was this convoy which met with tragedy.

The Commander-in-Chief in Plymouth was responsible for the safety of the rehearsal. Since German E-Boats, a fast-moving boat armed with torpedoes and a top speed of 40 knots now patrolled the English Channel at night, the Commander had placed extra patrols across the mouth of Lyme Bay, consisting of two Royal Navy destroyers, three motor torpedo boats and two motor gunboats. Another motor torpedo boat patrol was sent to watch Cherbourg, where the German E-Boats were based.

LST Group 32, the Plymouth section of Convoy T-4, consisted of five ships: LSTs 515, 496, 511, 531 and 58. The group left Plymouth at 9.45pm on the night of 27 April 1944. It was joined by the escort vessel, the corvette HMS Azelea, near the Eddystone Rocks and headed towards Brixham, where it was joined by the Brixham section of Convoy T-4, composed of three more ships: LSTs 499, 289 and 507.

The convoy was moving at a speed of 5 knots in a single row, keeping a distance of about 400 yards. A few minutes after 10.00pm a group of nine German E-Boats set out on a normal reconnaissance mission from their base in Cherbourg into the Lyme Bay area. They followed the usual channel route without any sign of a convoy or enemy ships. However, as they headed towards Lyme Bay, they suddenly came in visual contact with the LST convoy. Since they could not see any naval escorts, they quickly positioned themselves for a torpedo attack.

As the convoy approached Lyme Bay it manoeuvred a loop to head back towards the shore. It was here that the E-Boats made contact and opened fire. Shortly after 2.00am LST 507 was torpedoed, hitting its auxiliary engine room and cutting all electric power.

Trapped below decks, hundreds of soldiers and sailors went down with the ships. There was little time to launch lifeboats and some of these were jammed.

The ship burst into flames, the fire-fighting attempted by the crew proved futile as most of the equipment was inoperative due to the power failure. After about 45 minutes the survivors were ordered to abandon ship.

Shortly afterwards, LST 531 was hit by two torpedoes. The ship burst into flames, rolled over and sank in six minutes.

Several minutes later LST 289 was torpedoed. The ship managed to limp back to shore but only after suffering a number of deaths and casualties aboard.

Trapped below decks, hundreds of soldiers and sailors went down with the ships. There was little time to launch lifeboats and some of these were jammed. Of those who managed to leap from the ships, many were soon drowned, some weighed down by their waterlogged coats; some, because they had wrongly put on their life belts around their waists rather than under their armpits, while others succumbed to hypothermia in the cold water. In all 749 American soldiers and sailors died that night, 946 in total during Exercise Tiger.

Subsequent investigations revealed two main reasons for the tragedy: firstly, there was a lack of naval escort vessels. The convoy was supposed to have been accompanied by a World War I destroyer as well as the corvette. The destroyer was in port for repair and a replacement was not available.

Secondly, there was a blunder in communication. The radio frequencies issued to the escort ship, the command centre on shore and the LSTs contained serious typographical errors. The LSTs were on different radio frequencies to the corvette and the commanding officers on shore and did not communicate.

When the news reached the allied commanders it greatly worried them that so many lives were lost, particularly those of the missing officers who had plans which, if they fell into German hands, would reveal the Allied intentions for the D-Day landings. This was so serious that the Allied commanders even considered changing plans for Operation Overlord, fearing that the enemy must have discovered details of the invasion.

Miraculously, the bodies of every officer with BIGOT-level clearance (the very highest security rating) were found. The plans for D-Day were secure. Meanwhile, the tragedy was kept top secret and the survivors were strictly ordered not to talk about it.

The disaster was conveniently forgotten until 40 years after the Normandy landings. It was largely through the efforts of the late Ken Small, who in 1984 recovered a Sherman Tank from the sea threequarters-of-a-mile off the coast at Slapton, that the US and British Armies acknowledged the tragedy and the incident was unfolded to the world.

Article courtesy of Exercise Tiger Remembered, 2016.