The dress rehearsal of D-Day gone terribly wrong

Exercise Tiger

Operation Tiger, also known as “Exercise Tiger” was one of the large-scale dress rehearsals prior to D-Day set on Slapton Sands, Devon in southern England. This exercise, which took place 77 years ago between April 22 and April 30, 1944, ended in disaster as the Allied convoy carrying the soldiers preparing for the mock landing was attacked by real German E-boats, killing around 800 American servicemen.
 
As part of the build-up to D-Day, Force “U”, comprising American troops tasked with landing on Utah Beach, started training the different phases of landings at Slapton Sands. The location was chosen for its similarity to Utah Beach. The residents who lived near Slapton were evacuated in late 1943 to ensure complete secrecy. The purpose of these exercises was to give U.S. troops training in conditions very much resembling the ones awaiting them in Normandy. To make it as realistic as possible, Eisenhower even ordered troops to be landing under live fire over their heads on April 27. Due to uncoordinated changes in timing, many soldiers were killed on the beach by the naval bombardment that was supposed to take place before the landing, thus constituting the first friendly fire accident of the exercise. This was already a bad omen for the outcome of the operation.

In the early hours of April 28, approximately 30,000 American servicemen were heading towards Slapton Sands through Lyme Bay to simulate a landing when they were spotted by German reconnaissance planes and E-boats. The German Kriegsmarine had a base across the English Channel in Cherbourg, where they kept a flotilla of E-boats. These highly maneuverable small ships made of aluminum and timber were called Schnellboot (S-Boot for short) in German, literally “fast boats.” In Britain they came to be known as E-boats, with “E” standing for enemy. These German ships armed with torpedoes and guns and with a top speed of up to 40 knots patrolled the English Channel at night.

Nine German E-boats under the command of Lt. Commander Bernd Klug intercepted and opened fire on convoy T-4 of eight U.S. LSTs (Landing Ship Tank, nicknamed also Large Slow Target due to its low speed) sailing in a straight line and packed with equipment and troops. Two British ships, the destroyer HMS Scimitar and the corvette HMS Azalea were supposed to secure the area. The destroyer, HMS Scimitar had to return to the dockyards in Plymouth for repairs due to a collision with one of the LSTs. Its replacement, HMS Saladin, arrived too late. The other ship, the slow and outdated WWI-era HMS Azalea, had not much chance to repel the attack of the fast German boats in the darkness. The situation was exacerbated by communication problems caused by the American and British being on different radio frequencies. The slow-moving LSTs offered easy targets for the German E-boats. Many sailors believed their green tracers were part of the exercise. Three of the LSTs were hit by German torpedoes, two of them sank, resulting in hundreds of casualties among Army and Navy personnel. LST-289 was seriously damaged but made it back to the port in Dartmouth. The E-boats retreated to Cherbourg when the Allied vessels fired back. In the chaos, some of the LSTs started firing upon each other. Many servicemen drowned or died of hypothermia in the icy water while waiting to be rescued. An additional reason for the many casualties was the poor training on wearing the lifebelts. Due to the large backpacks, many soldiers placed them around their waist. When they jumped into the water, their heavy gear flipped them upside down, forcing their heads under water and drowning them.

A British officer, Julian Perkin, had horrifying memories of the disaster: “The sight was appalling. There were hundreds of bodies of American servicemen, in full battle gear, floating in the sea. Many had their limbs and even their heads blown off…. Those the doctor pronounced dead were pushed back into the sea [where] small American landing craft with their ramps down were literally scooping up bodies. It was a ghastly sight!”
 
Among the casualties were ten officers with BIGOT-level (standing for British Invasion of German Occupied Territory) clearance for D-Day, meaning that they had prior knowledge of the invasion. Their capture by the Germans could have compromised the landing. So serious was the situation that, fearing they were taken prisoner by the Germans, the invasion was nearly called off until the bodies of all ten victims were recovered.

The tragedy directed attention to a number of major issues that needed to be addressed before D-Day. One of them was the necessity to standardize radio frequencies to facilitate communication between escort vessels and landing craft. Those storming the Normandy beaches got better life-vest training, too. Friendly fire incidents were also to be avoided by means of better communication and coordination in the future. Allied leaders were furious and kept the debacle secret so as not to undermine morale, and the details were not made public until years later. The fallen were buried in military cemeteries in England. More Americans died during Exercise Tiger than on Utah Beach itself. The 4th Infantry Division lost fewer than 200 men on D-Day, while nearly 800 servicemen lost their lives on Slapton Sands.
 
There are several monuments remembering the casualties of the exercise. Devon resident Ken Small discovered several items from the exercise, including a Sherman tank, on the beach while beachcombing in the early 1970s. In 1974, he purchased the tank from the American government for $50 USD. In 1984, with the aid of locals, he raised the tank, which became a memorial to the incident. Another example to mention is a memorial plaque installed at Utah Beach on the wall of a former German bunker in 2012.

One of the German E-boats (S-130), considered the last of its kind, still exists and is being renovated by collector Kevin Wheatcroft in Mashfords, Cornwall. In the Cold War era, it was used to smuggle MI6 agents into the Baltic states, then it was handed over to the German navy for training purposes. Currently, it is hoped that after the renovation the boat will be on display in a dry dock bought by the Wheatcroft Collection in North Devon.