As Operation Overlord approached the Allies were embarking on the final exercises for troops involved in the invasion. The aim was to rehearse the movement of troops by sea in as realistic manner as possible, with the men making an equivalent length of journey to familiarise them with sea going conditions. It was not always a comfortable experience.
The last of the rehearsal exercises now began on the south coast of England, beginning with Exercise Tiger for the men destined for Utah beach. On the 28th April the Supreme Allied Commander, General Eisenhower was amongst the senior officers watching the manoeuvres at Slapton Sands. His aide Captain H. C. Butcher was accompanying him and recorded the day in his diary:
The maneuver, the code name for which is TIGER, was intended to simulate conditions of the actual landings on the 4th Division’s beach in France. This beach has water behind it and high ground commanding the beach. Our engineers had worked hard and long to copy the scheme of fortifications used on the shore on which the invasion landing is to be made. It had been thought that this large exercise would attract enemy air attacks or possibly attack by surface vessels, particularly E-boats, but none developed on D-Night or D-Day.
The principal innovation is the use of rockets aboard aircraft. The plane dives at the target and the rocket is released. The rocket accelerates to a high speed as the propulsion fluid burns, after which the speed diminishes. If a target is hit during the high speed, extraordinary effect is obtained. Several squadrons of Typhoons, which ﬂy 400 miles per hour, already have been equipped, as have been some American planes.
Then there was a delay in the landing; why, we did not know, although later we heard that H-Hour had been postponed even after the naval bombardment had begun for one hour. This left LCTs and their cargoes of DDs (tanks that float) milling around, waiting. In due time, the DDs were successfuly launched and slowly made their way toward the beach at three or four knots an hour.
One, I noticed, was smoking. It had proceeded about a mile somewhat parallel to the beach when I saw a yellow object pushed from the tank. I ﬁrst thought this was a marker buoy, but soon realized it was a dinghy and that the tank was in trouble. Soon an LCVP sped toward it. In a few moments, the tank crew was in the yellow dinghy and the tank had sunk. This was the only tank casualty and, fortunately, no one was lost.
Then the ﬁrst assault wave of infantry in LCVPs arrived from the transport vessels eight miles out. They landed either with or shortly after the amphibious tanks. This landing was preceded by rocket bombardment, at the postponed H-Hour, from three landing craft that had crept close to shore and ﬁred diagonally at the obstacles, including barbed wire, tank ditch, and other prepared positions. The rockets had made usable pathways through the barbed wire.
In this exercise effort was made to get tanks ashore quickly in order to use their ﬁre power. Engineers were brought in as rapidly as possible to demolish obstacles with hand-placed explosives. The tanks had to wait while these operations proceeded. If there had been enemy ﬁre, the tanks, being quite close together, would have been easy targets, as, indeed, would the landing craft.
I came away from the exercise feeling depressed. But frequently the poorest kind of exercise presages the best actual operation because the failures are noticed and corrected.
As the day closed, I was in Ike’s office when Beetle phoned on the intercommunication system to say that by E-boat action last night, we had two LSTs sunk and one damaged in the exercise. This happened off Lyme Bay—just where we had been. Casualties are estimated at 300 to 400. Beetle said this reduces our reserve of LSTs for the big show to zero.
The final figure for casualties put the total at 1405 dead with a further 200 injured. This compared with about 200 dead on Utah beach on the day of the invasion itself.
Naturally the whole event could not be fully acknowledged during war time, it was impossible to make any reference to the ‘D-Day rehearsals’. There was no ‘cover up’ but the true circumstances were not revealed at the time – and the incident was not remembered with a memorial for many years.
Although the disaster is associated with Slapton Sands in Devon, where the troops were exercising on the beaches, the incident happened some distance away in the Channel. The boats were actually torpedoed off Portland Bill in Dorset, within sight of gun crews on the cliff tops. Wartime attitudes about the exact circumstances of the incident meant that the facts were not uncovered for some time.
the precise locations of both Tank Landing Ships with references, courtesy the Admiralty Chart:
LST 507: Latitude 50˚ 26´ 08˝ N, Longitude 2˚ 44´ 01˝ W.
LST 531: Latitude 50˚ 26´ 08˝ N, Longitude 2˚ 43´ 39˝ W.
That puts them under between ten and eighteen fathoms of water, ten miles west-south-west of Portland Bill and twelve miles south of Burton Bradstock – which is 45 miles from Slapton Sands.
One of the E-boats, or German ‘Schnell’ boats, that took part in the attack, S-130, is now undergoing restoration in Britain