Exercise Tiger: D-Day Rehearsal Claimed The Lives of 946 and Was Kept Confidential Until 1988

Exercise Tiger: D-Day Rehearsal Claimed The Lives of 946 and Was Kept Confidential Until 1988

Patrick Lynch - June 1, 2017

The D-Day landing at Normandy on June 6, 1944, was one of the most pivotal events of World War II, but it was preceded by a disastrous rehearsal just over five weeks earlier. The ‘practice’ mission was specifically for the landing at Utah Beach. The disaster at Lyme Bay, off the coast of Devon, England, resulted in the deaths of at least 749 soldiers, a greater loss than that suffered by the Allies during the real Utah landing.

A Secret Dress Rehearsal

The D-Day landing was in the works for quite some time, and in late 1943, the British set up a training ground in Devon at Slapton Sands which was chosen for its similarity to Utah Beach. At this time, approximately 3,000 local residents were told they had six weeks to leave their homes; no explanation was given. In spring 1944, tens of thousands of American soldiers arrived and settled in Devon in preparation for the crucial event to come.

Exercise Tiger: D-Day Rehearsal Claimed The Lives of 946 and Was Kept Confidential Until 1988
Planning the Operation. Exercise Tiger Remembered

Slapton Sands was chosen as the venue for the rehearsal because they were long, wide and almost identical to the beaches of Normandy. The mission was given the name Operation Tiger and involved placing landing boats in the English Channel and ensuring they simulated a water landing on Devon’s beaches. The Allied commander, Dwight D. Eisenhower, was in charge of proceedings and he wanted to place the men in the rough areas of the channels so they could experience seasickness and realism.

The operation also included tank landing craft along with the ships. The idea was to have gunfire and shellfire to simulate what the Allies would face when they landed in France. In order to keep the mission a secret, Allied commanders shared no information with their troops.

Although there had been other landing rehearsals, Operation Tiger was the largest of the lot. It was due to take place from 22-30 April 1944 and was designed to cover all aspects of the invasion. A total of 30,000 troops were involved and work on the project was fast and furious. The Allies constructed fake enemy positions and concrete pillboxes while each assault team included 30 soldiers armed with an impressive arsenal including machine guns, flamethrowers, bazookas, and mortars.

Exercise Tiger: D-Day Rehearsal Claimed The Lives of 946 and Was Kept Confidential Until 1988
Men and Tanks involved in the operation. Exercisetigermemorial.co.uk

An Unexpected Battle

The initial landing went smoothly enough but disaster struck shortly after midnight on April 28. Convoy T-4, which included eight LSTs (nicknamed Long Slow Targets by their crews), sailed into the English Channel to continue the rehearsal. Unfortunately, there was a German fleet patrolling the area, and it picked up the Allied vessels on its radar. Recognizing that they had a sitting duck to aim for, the Germans launched a rapid attack and fired torpedoes at the helpless enemy.

There was a total of nine German E-Boats involved in the attack which became known as the Battle of Lyme Bay. One of the worst aspects of the incident was that the casualties could have been significantly reduced only for a simple typographical error in orders. The result was that the British naval headquarters ashore were on a different radio frequency to the Americans in the water. As a result, the ships near Lyme Bay had no idea of the danger until it hit them.

Although shore batteries knew about the German boats, they were under strict orders not to open fire and reveal their positions. An unfortunate accident earlier in the operation ensured the convoy was an easy target. There were supposed to be two ships protecting the convoy, but the HMS Scimitar had suffered damage after an accident with an LST and was not available. As a result, the HMS Azalea led the ships in a straight line, a formation that was criticized for making the convoy an easy target.

The Azalea spotted the E-Boats but assumed the landing craft knew of their existence so he did not inform them of the German presence on the water. It was only when the attack started that the lack of security around the convoy became known. HMS Saladin was dispatched a few minutes after the attack began but it was too late.

Three ships were hit in the initial attack; LST 507 caught fire and had to be abandoned, LST 531 suffered a direct hit and quickly sank while LST 289 was also hit and in flame but managed to make it to the shore. The landing craft was attacked so suddenly that there was no time to launch life rafts. Allied commanders wanted to avoid further direct hits, so they ordered the ships to split up. However, it was a death sentence to the men already in the water as they were left to die. According to eyewitness accounts, soldiers were weighed down by their gear and sank. Others had put their lifejackets on incorrectly by wearing them around their waists instead of their armpits.

According to survivors, you could “walk to the beach on the dead bodies.” Although estimates vary, it’s likely that over 700 men died during the attack. Although the Azalea fired upon the enemy, the German ships emerged from the battle unscathed. If the Allies thought things couldn’t get any worse, they were sorely mistaken.

Exercise Tiger: D-Day Rehearsal Claimed The Lives of 946 and Was Kept Confidential Until 1988
Memorial Plaque to those who died in Operation Tiger. Submerged.co.uk

Killed By Your Own

Although what happened next is open to question, survivors claim that soldiers died due to friendly fire. To this day, the Pentagon refuses to acknowledge the incident. Most of the ships that survived the attack moved towards Slapton Sands, but it was here that Eisenhower’s desire for real ammunition proved devastating.

During the operation, the shelling was supposed to stop shortly before the Americans soldiers reached the shore. Due to an appalling mix-up in timing, the British were still shelling the beach when the Americans arrived on the shore. The British were supposed to be using dummy ammunition at that point but continued using live rounds. As a result, an estimated 300 Americans died on the beach.

Exercise Tiger: D-Day Rehearsal Claimed The Lives of 946 and Was Kept Confidential Until 1988
Damaged LST. Dougs Darkworld WordPress


The official death toll from the Operation Tiger disaster is 749 although it could be much higher. Even if you take the official total as fact, it represented the greatest loss of American life in World War II since the attack on Pearl Harbor. 10 of the missing soldiers were of extreme importance. These men were known as ‘BIGOTS’ who had classified information about the D-Day landing. As a result, the entire operation was put on hold until the Allies were able to account for the missing troops.

Operation Tiger remained a secret for approximately 40 years as those involved were ordered not to reveal any details of the incidents. Also, those that died were either buried at the U.S. cemetery in England or were brought home. Even the medical staff that treated the men were ordered not to ask questions about how they got their injuries. The Allies were concerned that the Germans would find out what they did and get wind of the D-Day plan. In fact, the Germans believed they blew up a line of tankers. Incidentally, Admiral Moon committed suicide soon after the disaster.

As catastrophic as Operation Tiger was, it paved the way for success at Normandy. The Allied commanders requested better life jackets and ensured every soldier was properly trained in its use. Also, a special system was implemented to save soldiers in the water. Crucially, the Allies used the disaster to fix their poor communication system. All radio frequencies were standardized to ensure a similar miscommunication blunder could not happen on D-Day. Just over five weeks after Operation Tiger, Allied troops stormed the beaches of Normandy in a victory pivotal to the defeat of the Nazis in World War II.