Open main menu

American troops landing on Slapton Sands in England during rehearsals for the invasion of Normandy

Exercise Tiger, or Operation Tiger, was one of a series of large-scale rehearsals for the D-Day invasion of Normandy, which took place in April 1944 on Slapton Sands in Devon. Coordination and communication problems resulted in friendly fire deaths during the exercise, and an Allied convoy positioning itself for the landing was attacked by E-boats of Nazi Germany's Kriegsmarine, resulting in the deaths of at least 749 American servicemen.[1][2] Because of the impending invasion of Normandy, the incident was under the strictest secrecy at the time and was only nominally reported afterwards.



Landing operationsEdit

In late 1943, as part of the build-up to D-day, the British government set up a training ground at Slapton Sands, Devon, to be used by Force "U", the American forces tasked with landing on Utah Beach. Slapton Beach was selected for its similarity to Utah Beach: a gravel beach, followed by a strip of land and then a lake. Approximately 3,000 local residents in the area of Slapton,[3] now South Hams District of Devon, were evacuated.[4] Some had never left their villages before being evacuated.[5]

Landing exercises started in December 1943. Exercise Tiger was one of the larger exercises that took place in April and May 1944. The exercise was to last from 22 April until 30 April 1944, and covered all aspects of the invasion, culminating in a beach landing at Slapton Sands. On board nine large tank landing ships (LSTs), the 30,000 troops prepared for their mock landing, which also included a live-firing exercise.

Protection for the exercise area came from the Royal Navy. Two destroyers, three Motor Torpedo Boats and two Motor Gun Boats patrolled the entrance to Lyme Bay and Motor Torpedo Boats watched the Cherbourg area where German E-boats were based.

The first phase of the exercise focused on marshalling and embarkation drills, and lasted from 22 to 25 April. On the evening of 26 April the first wave of assault troops boarded their transports and set off, the plan being to simulate the Channel crossing by taking a roundabout route through Lyme Bay, in order to arrive off Slapton at first light on 27 April.

Friendly fire incidentEdit

The first practice assault took place on the morning of 27 April[6][7] and was marred by an incident involving friendly fire. H-hour was set for 07:30, and was to include live ammunition to acclimatize the troops to the sights, sounds and even smells of a naval bombardment. During the landing itself, live rounds were to be fired over the heads of the incoming troops by forces on land, for the same reason. This followed an order made by General Dwight D. Eisenhower, the Supreme Allied Commander, who felt that the men must be hardened by exposure to real battle conditions.[8] The exercise was to include naval bombardment by ships of Force U Bombardment Group fifty minutes prior to the landing.[9]

Several of the landing ships for that morning were delayed, and the officer in charge, American Admiral Don P. Moon, decided to delay H-hour for 60 minutes, until 08:30.[8] Some of the landing craft did not receive word of the change. Landing on the beach at their original scheduled time, the second wave came under fire, suffering an unknown number of casualties. Rumours circulated along the fleet that as many as 450 men were killed.[10]

Battle of Lyme BayEdit

Battle of Lyme Bay
Part of World War II
Arrow shows Lyme Bay in south-west England
Date28 April 1944
50°16′48″N 3°38′51″W / 50.28°N 3.64750°W / 50.28; -3.64750Coordinates: 50°16′48″N 3°38′51″W / 50.28°N 3.64750°W / 50.28; -3.64750
Result German victory
  United States
  United Kingdom
1 corvette
8 LSTs
9 E-boats
Casualties and losses
746 killed
~200 wounded
2 LSTs sunk
2 LSTs damaged

On the day after the first practice assaults, early on the morning of 28 April, the exercise was blighted when Convoy T-4, consisting of eight LSTs carrying vehicles and combat engineers of the 1st Engineer Special Brigade, was attacked by nine German E-boats under the command of Korvettenkapitän Bernd Klug, in Lyme Bay.

Of the two ships assigned to protect the convoy, only one was present. HMS Azalea, a corvette, was leading the LSTs in a straight line, a formation that later drew criticism since it presented an easy target to the E-boats. The second ship that was supposed to be present, HMS Scimitar, a World War I destroyer, had been in a collision with an LST, suffered structural damage and left the convoy to be repaired at Plymouth.[11] Because the LSTs and British naval headquarters were operating on different frequencies, the American forces did not know this.[8] HMS Saladin was dispatched as a replacement, but did not arrive in time to help protect the convoy.[12]

The E-boats had left Cherbourg on patrol the previous evening and did not encounter the Allied patrol lines off Cherbourg or in the English Channel. They spotted the convoy and attacked.[a]


  • LST-289 was set on fire but eventually made it back to shore with the loss of 13 Navy personnel.[14]
  • LST-507 was torpedoed and sunk with the loss of 202 US Army/US Navy personnel.[14]
  • LST-511 was damaged by friendly fire with the loss 18 US Army/Navy personnel [Injured].[15]
  • LST-531 sank within six minutes of being torpedoed with the loss of 424 Army and Navy personnel.[1][2][14]

The remaining ships and their escort fired back and the E-boats made no more attacks. In total, 749 servicemen (551 United States Army and 198 United States Navy) were killed during Exercise Tiger.[2][16] Many servicemen drowned or died of hypothermia in the cold sea while waiting to be rescued. Many had not been shown how to put on their lifebelt correctly, and placed it around their waist, the only available spot because of their large backpacks. In some cases this meant that when they jumped into the water, the weight of their combat packs flipped them upside down, dragging their heads under water and drowning them.[17] Dale Rodman, who travelled on LST-507, commented: "The worst memory I have is setting off in the lifeboat away from the sinking ship and watching bodies float by."[5] The 248 bodies that were recovered were sent to Brookwood Cemetery in Surrey on 29 April.[18] This highest army casualites were members of the 1st Special Engineer Brigade.[19]


As a result of official embarrassment and concerns over potential leaks just prior to the real invasion, all survivors were sworn to secrecy by their superiors. Ten missing officers involved in the exercise had BIGOT-level clearance for D-Day, meaning that they knew the invasion plans and could have compromised the invasion should they have been captured alive. As a result, the invasion was nearly called off until the bodies of all ten victims were found.[8] As it was, the mere similarity between Slapton Sands and the Calvados coast caused Adolf Hitler to deduce that the exercise was a practice for a landing in Normandy and to insist on the need to reinforce lower Normandy.[20]

There is little information about exactly how individual soldiers and sailors died. The US Department of Defense stated in 1988 that record-keeping may have been inadequate aboard some of the ships, and the most pertinent log books were lost at sea.[21] A ninth LST (LST-508) was scheduled to be in the convoy, but was damaged. Author Nigel Lewis speculates that some or all of its infantrymen may have been aboard LST 507 when it went down.[22] Various eyewitness accounts detail hasty treatment of casualties and rumours circulated of unmarked mass graves in Devon fields.[8]

Several changes resulted from mistakes made in Exercise Tiger:

  • Radio frequencies were standardised; the British escort vessels were late and out of position due to radio problems, and a signal of the E-boats' presence was not picked up by the LSTs.
  • Better life vest training for landing troops
  • New plans for small craft to pick up floating survivors on D-Day

Official histories contain little information about the tragedy. Some commentators have called it a cover-up, but the initial critical secrecy about Tiger may have merely resulted in longer-term quietude. In his book The Forgotten Dead: Why 946 American Servicemen Died Off The Coast Of Devon In 1944 – And The Man Who Discovered Their True Story, published in 1988, Ken Small declares that the event "was never covered up; it was 'conveniently forgotten'".[8] The casualty statistics from Tiger were not released by Supreme Headquarters Allied Expeditionary Force (SHAEF) until August 1944, along with the casualties of the actual D-Day landings. This report stated that there were 442 army dead and 197 navy, for a total of 639.[23] (However, Moon had reported on 30 April that there were 749 dead.[16]) Charles B. MacDonald, author and former deputy chief historian at the U.S. Army Center of Military History, notes that information from the SHAEF press release appeared in the August issue of Stars and Stripes.[1] MacDonald surmises that the press release went largely unnoticed in light of the larger events that were occurring at the time.[1] The story was detailed in at least three books at the end of the war, including Captain Harry C. Butcher's My Three Years With Eisenhower (1946),[24] and in several publications and speeches.[1] Gordon A. Harrison mentioned it in the official Army history Cross-Channel Attack (p. 270) and Samuel Eliot Morison discussed it in his official Navy history, US Naval Operations, vol. 11, p. 66.


Sherman DD tank at the Torcross memorial
Memorial plaque at Utah Beach

Devon resident and civilian Ken Small took on the task of seeking to commemorate the event, after discovering evidence of the aftermath washed up on the shore while beachcombing in the early 1970s.[25]

In 1974, Small bought from the U.S. Government the rights to a submerged tank from the 70th Tank Battalion discovered by his search efforts. In 1984, with the aid of local residents and diving firms, he raised the tank, which now stands as a memorial to the incident. The local authority provided a plinth on the seafront to put the tank on, and erected a plaque in memory of the men killed. Ken Small documents how the local villagers were of more assistance than either the US or UK military officials.[citation needed] Later the American military honoured and supported him. Small died of cancer in March 2004, a few weeks before the 60th anniversary of the Exercise Tiger incident.

A plaque was erected, in 1995, at Arlington National Cemetery entitled "Exercise Tiger Memorial". In 1997, the Exercise Tiger Association[26] established a memorial to Exercise Tiger veterans in Mexico, Missouri. It is a 5,000-pound stern anchor from an LST of the Suffolk County Class on permanent loan from the Navy. In 2006, the Slapton Sands Memorial Tank Limited (a non-profit organisation, one of whose directors is Small's son Dean) established a more prominent memorial listing the names of all the victims of the attacks on Exercise Tiger.[27] In 2012, a plaque memorialising the tragedy was erected at Utah Beach, Normandy, on the wall of a former German anti-aircraft bunker. An M4 Sherman tank stands as a memorial to Exercise Tiger at Fort Rodman Park in New Bedford, Massachusetts.

In popular cultureEdit

  • Sanford Margalith's novel Captains is a fictionalized account of his experiences during the Slapton Sands incident[28][29]
  • A major plotline of Foyle's War was based on the Slapton Sands disaster, in the episode entitled "All Clear".
  • The Leslie Thomas novel The Magic Army is a fictionalized account of the evacuation of Slapton and the events leading up to the Slapton Sands disaster
  • A major plot line of James R. Benn's novel The Rest Is Silence, one of the Billy Boyle series, is based on Operation Tiger at Slapton Sands.


  1. ^ One of these E-Boats was S-130, now in dry dock in Plymouth, Devon.[13]


  1. ^ a b c d e MacDonald, Charles B. (June 1988). "Slapton Sands: The 'Cover Up' That Never Was". Army. Naval Historical Center. 38 (6): 64–67.
  2. ^ a b c Fenton, Ben (26 April 2004). "The disaster that could have scuppered Overlord". The Daily Telegraph. Retrieved 30 June 2016.
  3. ^ "South Devon Evacuation 1944". 16 November 1943. Retrieved 28 April 2014.
  4. ^ "Slapton Line: Slapton Monument Rededication". Devon County Council. 9 March 2007. Archived from the original on 31 May 2016. Retrieved 6 August 2016.
  5. ^ a b Stokes, Paul (29 April 1994). "Veterans honour 749 who died in D-Day rehearsal". The Daily Telegraph. London.
  6. ^ Dear, Ian; Foot, M.R.D. (2001). The Oxford companion to World War II. New York: Oxford University Press. p. 787. ISBN 0-19-860446-7.
  7. ^ Herman, Jan K (1997). Battle Station Sick Bay: Navy Medicine in World War II. Annapolis: Naval Institute Press. p. 191. ISBN 1-55750-361-3.
  8. ^ a b c d e f Small, Ken; Rogerson, Mark (1988). The Forgotten Dead – Why 946 American Servicemen Died Off The Coast Of Devon In 1944 – And The Man Who Discovered Their True Story. London: Bloomsbury. ISBN 0-7475-0309-5.
  9. ^ Lewis 1990, p. 252.
  10. ^ Lewis 1990, p. 254.
  11. ^ Mason, Geoffrey B. (2003). "HMS Scimitar, destroyer". Naval Retrieved 6 August 2016.
  12. ^ Lewis 1990, p. 75.
  13. ^ "Schnellboot S130". British Military Powerboat Team. 7 November 2004. Retrieved 6 August 2016.
  14. ^ a b c "Operation Tiger". Combiner Operations Command. Retrieved 4 July 2019.
  15. ^ exercise Tiger UK LST 311 casuality report
  16. ^ a b Lewis 1990, p. 227.
  17. ^ Lewis 1990, pp. 64, 114–115.
  18. ^ Lewis 1990, p. 237.
  19. ^ Quartermaster Museum
  20. ^ Harrison, Gordon, Cross-Channel Attack, Office of the Chief of Military History, Department of the Army, Washington, D. C., 1951, p. 259.
  21. ^ Lewis 1990, p. 220.
  22. ^ Lewis 1990, p. 232–233.
  23. ^ Lewis 1990, p. 228.
  24. ^ Butcher, Harry C. My Three Years with Eisenhower: The Personal Diary of Captain Harry C. Butcher, USNR, Naval Aide to General Eisenhower, 1942 to 1945. pp. 528, 535.
  25. ^ Jones, Claire (30 May 2014). "The D-Day rehearsal that cost 800 lives". BBC News online. Retrieved 6 August 2016.
  26. ^ "Memorials to Exercise Tiger". Exercise Tiger Association. Retrieved 6 August 2016.
  27. ^ Casson, John. "Exercise Tiger Remembered". Retrieved 6 August 2016.
  28. ^ "Fiction Book Review: CAPTAINS by Sanford Margalith". Publishers Weekly. March 2001. Retrieved 6 June 2019.
  29. ^ Margalith, Sanford H. (2001). Captains. Bedford, IN: JONA Books. p. 224. ISBN 978-0-9657929-8-1.


  • Garn, Kenneth H. (2004). The Secret D-Day. ISBN 0-7884-2512-9.
  • Lewis, Nigel (1990). Exercise Tiger: The Dramatic True Story of a Hidden Tragedy of World War II. New York: Prentice-Hall. ISBN 0-13-127796-0.
  • Lewis, Nigel (2017). The Cover Plan Conspiracy: The British and Exercise Tiger, 1944: Kindle e-book.
  • Thomas, Leslie. (1981). The Magic Army. ISBN 0099469170.

External linksEdit