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H-029-1: The Exercise Tiger Debacle, 28 April 1944

Photo #: 80-G-302423 Rear Admiral Don P. Moon, USN
Rear Admiral Donald P. Moon, USN, circa 1944 (80-G-302423).

H-Gram 029, Attachment 1

Samuel J. Cox, Director NHHC

April 2019

The Allied Invasion of northern France was finally set for late spring 1944, after much prodding by the U.S. Joint Chiefs and pressure exerted by Soviet dictator Josef Stalin finally overcame Allied reluctance to launch an invasion at that point.1944. In hindsight, the British position in particular seems unjustified, but the American experience on the Western Front in World War I was only a fraction of the horror the British had encountered—the memory of the first day of the Battle of the Somme (20,000 British dead in one day in exchange for a few yards) was deeply embedded in the British psyche. (Even that couldn’t compare to the bloodbath taking place on the Eastern Front between German and Soviet armies, which is why Stalin was so aggravated by the delay in opening a second front in Europe. In terms of deaths and destroyed armies and divisions, Normandy and the Western Front was a sideshow compared to the Eastern Front.)

U.S. General Dwight D. Eisenhower had been named Supreme Allied Commander in Europe, but British General Sir Bernard Montgomery was responsible for much of the planning for the Allied invasion on the Normandy coast of France.  Three British and Canadian divisions were planned to go ashore at Gold, Juno and Sword Beaches, to the east of the U.S. beaches. Somewhat belatedly, Montgomery added a requirement for a second U.S. division to go ashore (at Utah Beach) in addition to the one already planned. As a result, “Assault Force U” was hastily formed to execute the transport and landing of the U.S. 4th Infantry Division on Utah Beach, which lay between Omaha Beach to the west and the British/Canadian beaches to the east.

Rear Admiral Don P. Moon was named commander of Assault Force U (TF 125.) Moon had been near the top of his class at the U.S. Naval Academy (fourth, although some accounts say first.) He was an officer with a great reputation and was responsible for numerous innovations and technical advancements, particularly in the field of gunnery. He was also a perfectionist who drove himself hard, sleeping only about four hours a day. He had combat experience earlier in the war on the Murmansk Run and in North Africa and had survived service on Chief of Naval Operations Admiral Ernest J. King’s staff well enough to be promoted to rear admiral and then to be given command of Force U.

Although the planned Allied landings on the north coast of France were covered by a massive deception effort to conceal the exact place and time, it was no secret to the Germans that U.S. and British forces were conducting numerous large-scale rehearsal landings on British beaches in preparation for the invasion. These preparations had begun in earnest as early as January 1944. Because of its late formation, Force U was behind the power curve in preparation for the invasion, but by late April Force U was ready enough to commence large-scale rehearsals. The location selected was Slapton Sands, a beach at Lyme Bay on the south coast of England, due to its close resemblance to Utah Beach, on the other side of the Channel.

Operation Tiger was a full-dress rehearsal for the Utah Beach landings and was scheduled for 22 to 30 April 1944. The first five days were allocated for loading and embarkation, with the landing of the first echelon (with assault troops) set to take place on 27 April and the landing of a second echelon (with support troops) scheduled for 28 April. Other echelons to follow. Under the command of Rear Admiral Moon, embarked on Bayfield (APA-33,) Force U and embarked troops and gear were to participate. These would conduct an extended transit in order to precisely simulate—sea sickness and all—the cross-Channel voyage for the troops. The ships were fully loaded, as were the vehicles on the ships—with fuel and ammunition (far more than was required for the training evolution, but again the intent was to hew as closely as possible to the real operation). As an aside, one of the crewman on the flagship Bayfield was Gunner’s Mate Lawrence Peter Berra, who would later be known as legendary New York Yankees’ manager “Yogi” Berra.

Almost the entire Force U participated, including 21 tank landing ships (LST), 28 large utility landing craft (LCU[L]) 65 tank landing craft (LCT) and nearly 100 smaller vessels. Although it was mostly an American force, British and other Allied ships participated. The mixed nature of the force (and other D-day forces) was viewed with great skepticism by CNO King and other senior U.S. Navy leaders, who assumed that mixing U.S. ships with other navies would lead to communications problems and other foul-ups (and they were right.) However, such concerns had been rejected by the senior Allied naval commander for the D-day invasion, British Admiral Sir Bertram Ramsey.

The first-echelon landings on 27 April were marked by significant confusion and delays. The landings were accompanied by Allied ships bombarding the beach with live ammunition in order to make the exercise as realistic as possible, but delays and communications problems resulted in some troops being landed into the live fire, resulting in deaths. The number of “friendly fire” deaths remains uncertain to this day. Some accounts claim as many as 450 were killed. However, these numbers appeared to be based on after-the-fact recollections of local civilians, who had been evacuated from the area at the time, and are probably conflated with the deaths as a result of the disaster that occurred at sea that night. U.S. Army records do not indicate landing deaths anywhere near those numbers, which naturally cause some writers to allege a “cover up.” In one case, Rear Admiral Moon ordered an hour delay only five minutes before execution, and not surprisingly many units did not get the word. General Eisenhower was an observer to the exercise and although his assessment is not known, members of his staff were reported to have been depressed and disillusioned by the result. Then things got worse.

Elements of the Second Echelon force departed British ports for a night transit to the landings scheduled for the morning of 28 April. These included Convoy T-4 departing Plymouth, Brixham, and Portsmouth under the command of U.S. Navy Commander Bernard Skahill, initially consisting of eight U.S. LSTs escorted by the British destroyer HMS Scimitar and the British corvette HMS Azalea. However, Scimitar and another vessel collided (some accounts say it was with a ninth LST in the convoy) and had to return to port. Although Skahill saw Scimitar heading off in an unexpected direction, the combination of the requirement to maintain radio silence, coupled with the fact that the U.S. convoy through some snafu (as feared by King) weren’t on the correct British radio frequency, meant that Skahill did not realize that he had lost his most capable escort. (Azalea was a WWI-vintage corvette with limited speed and armament, although the LSTs were even slower.) The destroyer HMS Saladin was dispatched to replace Scimitar but Skahill didn’t know that, and she would get there too late anyway. Worse, by monitoring the wrong frequency, the U.S. convoy did not receive broadcast warnings when British radar detected a force of German S-boats (fast torpedo boats) approaching the English coast from Cherbourg.

A force of nine German S-boats, under the command of Korvettenkapitän Bernd Klug departed Cherbourg in search of targets in the English Channel, which on this night turned out to be full of them. The S-boats (Schnellboot—“fast boat”) were referred by the Allies as E-boats (“Enemy” boats). They were similar to U.S. PT-boats, except for being bigger, faster, with a longer range, and more sturdily constructed, with less flammable fuel (diesel vice gasoline) and, although German torpedoes could be cantankerous, they were generally more reliable than those employed by the U.S. Navy. PT-boat torpedoes (which were generally armed with leftover early vintage aerial torpedoes). Each S-boat was armed with four 21-inch torpedoes (two tubes with reloads), and usually a 37-mm cannon (or a 40-mm Bofors gun) and three 20-mm (one twin mount and one single). The biggest drawback to S-boats operations was that the Germans didn’t have enough of them.

The German S-boats detected the convoy T-4 as Azalea led the eight LSTs in a straight line with no zigzagging. (Due to the LSTs slow speed, it wouldn’t have made much difference if it had been zigzagging.) The S-boats remained undetected by Azalea or the LSTs as they circled around to attack the rear of the convoy from behind.

The first sign of trouble was after 0100 when a scraping noise was heard underneath LST-507–– probably the sound of a German torpedo passing just underneath the shallow draft amphibious vessel. The skipper of LST-507 ordered general quarters and noted tracer fire (which apparently didn’t hit the ship) but assumed it was part of realistic training. For whatever reason, it was almost an hour before the Germans re-attacked, possibly regrouping after seeing no discernable result from the first attack (torpedoes may have gone under other LSTs without being properly identified.)

At 0207 a German torpedo struck LST-507 amidships in the auxiliary engine space, knocking out power and communications. The hit was devastating, starting a massive conflagration in the main cargo area as vehicles full of gasoline ignited, creating a blast furnace effect within the ship. Many of the more than 400 Army troops on board died in the flames. A second torpedo hit the ship and she began to sink. Eleven minutes later, two torpedoes in quick succession hit LST-531 and perhaps more mercifully sent her to the bottom in only six minutes.

The skipper of LST-289, Lieutenant Henry A. Mettler, saw torpedoes inbound in enough time to put the helm hard over and avoid a broadside hit. One torpedo hit the stern, which had crews’ living spaces. The burning stern broke off and then sank, but the main part of the LST was spared, and the crew was able save the forward part of the LST from going down, thus keeping hundreds of soldiers out of the water. By this time, however, chaos had gripped the force. LSTs were firing on each other in the dark and at least one was hit. Skahill gave the order for the convoy to scatter and return to port. Azalea reversed course when the trail LSTs started getting hit, but her crew could not tell which direction the attack was coming from. Being unable to communicate with the LSTs didn’t help. The skipper of Azalea, Commander George C. Geddes, RN, didn’t dare launch illumination rounds for fear of silhouetting the rest of the convoy and aiding the German attack. In the end, Azalea never had the chance to fire a shot, not that she had any hope of running down an S-boat. The soldiers on the LSTs that went down were from the 557th Quartermaster Railhead Company and 3206th Quartermaster Service Company. These were support troops that never expected to be in front-line combat.  They did not have Navy kapok life jackets, but had been issued an inner-tube device, for which they had not been adequately trained, that when worn incorrectly would flip the soldier over and drown him. Many soldiers perished in exactly that manner, before they died of hypothermia.

LST-289 enters Dartmouth Harbor, England, after being torpedoed by German S-boats during invasion rehearsal operations off Slapton Sands, England, on 28 April 1944. Note LCVPs still on the ship's davits (80-G-283501)

As the convoy scattered, which was standard procedure for such an event, there was initially no attempt to rescue survivors, which was also standard procedure, as doing so would only invite more ships to be sunk by torpedoes. Nevertheless, as Skahill’s flagship, LST-515, drew away from the scene there was a borderline mutiny. The skipper of LST-515, Lieutenant John Doyle, argued with Skahill to go back for survivors, knowing that it would not take long for anyone in the water to die from the cold. Skahill initially refused and Jones put the question to his crew for a “voice vote” about going back, and the crew responded with a rousing affirmative. Skahill gave in and LST-515 returned to the scene along with HMS Saladin and rescued several hundred soldiers and sailors, many badly burned, and most with advanced hypothermia.

Exactly how many U.S. Soldiers and Sailors were lost that night remains contentious even today, as initially there were over 100 missing, including ten officers who had “Bigot” clearance (i.e., knowledge of the D-Day invasion details). An extensive search was made until all ten were accounted for as being dead. The number 198 for U.S. Navy dead appears to be generally accepted, which is higher than the number of U.S. Navy killed during the D-Day landing on 6 June 1944. Some sources give Army dead as 441. Others say 441 dead plus 110 missing for a loss of 551, and a total of 749 U.S. personnel (which also happens to be the number on the monument in Weymouth, England to the disaster).  Another source says that the 749 figure only counts Army and that adding the Navy’s death toll raises the total to 947. Yet other sources assert that all these numbers are grossly undercounted as there was supposedly a massive cover-up after the fact. The moral of this story is don’t believe everything you read on the internet. There was definitely a lid of secrecy and censorship clamped on the event in the immediate aftermath so as to prevent the Germans from knowing what they accomplished. However, by July, general descriptions of what had happened had already appeared in Stars and Stripes, so I don’t consider the massive conspiracy to cover-up stories vey plausible.

The next day, Rear Admiral Moon went aboard Rear Admiral Alan G. Kirk’s flagship, Augusta (CA-31) to explain what had happened. Kirk was the commander of U.S. Navy forces involved in the D-day landings, and the (mostly U.S.) Western Naval Task Force, which included Assault Force U (TF 125) for Utah Beach and Assault Force O (TF 124) for Omaha Beach. (All of this fell under the overall naval command of British Admiral Ramsey.) Moon’s reception by Kirk was frosty, and downright hostile by Kirk’s chief of staff, Rear Admiral Arthur Struble, who insinuated that Moon had been derelict in his duty. There was no question that as commander of Force U, Moon bore responsibility for what happened, but on that night the enemy got the deciding vote. Nevertheless, from the debacle came numerous lessons learned (such as ensuring soldiers were properly trained in the use of lifebelts), which Moon rapidly implemented before the D-Day landings. Force U’s performance during the actual invasion was exemplary, and Moon handled the force very adroitly. Weaker German resistance at Utah Beach, especially compared to Omaha Beach, was a significant factor as well, but the resistance at Utah Beach was still very stiff, and Moon deserved much credit for overcoming it.)

It is quite possible that, perfectionist that he was, Moon didn’t deal well with the numerous foul-ups during the rehearsal and as were inevitable in combat. It is also quite likely that the loss of so many men under his command troubled him greatly. Talk about the possibility of him being held to account by a court of inquiry or even court-martial, as some senior Navy officers seemed to desire, probably didn’t help his state of mind. His constant lack of sleep was well known. All may have been factors when Moon took his own life on 5 August 1944 with a .45 caliber pistol in his stateroom aboard Bayfield off Naples on the eve of the invasion of southern France. I do place credence in reports from Bayfield’s crew that Moon suffered a bad head injury during darkened ship, which resulted in constant and severe headaches. His suicide note states that “the mind is gone. I am sick, so sick,” but also describes the fear that he might black out at a critical time during the invasion and cost more men their lives. Instead of asking to be relieved, he took his own life, leaving behind a wife, four children, and many heartbroken shipmates.

Sources: There are a number of articles on Exercise Tiger, some with wildly conflicting casualty estimates and some hyping the “cover-up” of the debacle. The one I think is best is “Exercise in Tragedy: Practice for the D-Day Landings” by Craig Symonds, in World War II Magazine, 15 February 2017. Another good one is “We’re Gonna Die!” by Joseph Balkoski, 28 April 2014 ( For background on Rear Admiral Moon, see Stephen Sussna, Defeat and Triumph: The Story of a Controversial Allied Invasion and French Re-birth (2008), and, of course, Rear Admiral Samuel Eliot Morison, History of U.S. Naval Operations in World War II, Vol. XI: The Invasion of France and Germany (1957).

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Published: Fri May 03 15:08:01 EDT 2019