What Happened during Exercise Tiger?
This weekend will mark the 75th anniversary of Exercise Tiger, the D-Day Rehearsals in which hundreds of US Military personnel lost their lives. Historian Harry Bennett explains how the tragedy at Slapton Sands unfolded

Published on April 24, 2019

Thank you Harry for taking the time to speak with us about Exercise Tiger. Why was the Operation initially conceived, and what did allied forces hope to accomplish by staging it?

Exercise Tiger is one of a series of operations that are held in preparation for D-Day. Landing troops, the co-ordination of forces (naval, air and army), the delivery of specialist engineering support, and follow up logistical operations are the military equivalent of a theatrical production where everything has to come to together in perfect harmony to achieve the desired effect. In a combat environment, the fallout from not getting it right is massive. Lives are going to be lost, ships sunk and aircraft downed. Battles hinge on effective all-arms co-operation and, in the circumstances of D-Day, the outcome of the war is at stake. If D-Day had gone badly wrong the invasion might have been defeated at the water's edge, or the Germans might have been in a position to roll in on the forces stuck on the beaches. D-Day has to go right. If June 6 1944 goes wrong it is going to take them at least another twelve months to get the forces together for a repeat invasion and by that stage the Russians will have overrun much of Europe. You have to practice landing techniques before the day itself and it has to be under the most realistic conditions.

Why was Slapton Sands chosen for the Operation?

American forces take over two large areas of the county of Devon in 1943. On the North Coast they create an Assault Training Center to practice small unit landings, use of mortars, flamethrowers, de-mining, taking out pillboxes etc. On the South Devon Coast they clear a large area around Slapton and create an area where they can practice all arms work, including beach head assault. In other words, at Slapton they upscale and bring together the techniques perfected at the Assault Training Center. They can conduct live firing as part of assault preparation before the troops go in and the conditions are going to be as realistic as possible.

The Slapton area is remote, giving you a degree of secrecy, and there aren't that many people who have to be evacuated. The area also has some similarities to the Utah Beach area which is one of the targets on 6 June.

What protection was laid out to secure the troops who were taking part in the exercise?

The protection comes in various forms:

- Close support (British Flower Class Corvette - slow and completely inadequate for protection work - it is more there as a kind of moral support). A destroyer was also due to provide close support for the convoy but was damaged before leaving port (a destroyer would have been much more useful against the German vessels).
- The guns of the LST's (they packed quite a punch even if the LST's lived up to their nickname of 'Large Slow Target').
- Distant support - Patrols of destroyers in the Channel together with other naval vessels designed to spot and respond to any incursion of German vessels. That is backed by radar (on ships and shore) with destroyer reinforcements available at Plymouth and Portsmouth. Also aircraft are at nearby airbases which can be tasked to intercept German forces.

Bottom line is that the British have screens of warships in the Channel designed to keep the Germans away from the coast of the UK. In the event of the T4 convoy the Germans are able to get past those screens.

There seem to be two major incidents that took place towards the end of the week long exercise. On April 27, 1944 there was an issue with Friendly Fire?

Several authors have referred to a friendly fire incident on 27 April when, because of a mix up over times, troops landed as a preparatory barrage dropped on the beach. Witness testimony to support this incident comes from those observing it at a distance. Bottom line is that there is no list of casualties relating to that incident, and I have yet to meet anyone who says that he survived the incident or that his buddy was killed during it. We just don't know enough about the incident to understand it, or how serious it was. That being said, it is pretty clear that we have men being injured and killed at Slapton across a range of incidents (and not just in April 1944). These involve things like mortar rounds dropping short, men being run over on the beach, accidental weapons discharge and a whole host of other things. They are training hard and casualties result. So, were there two incidents, including the torpedoing of 3 LSTs? In reality, we have one major casualty event (the T4 convoy), a suspected mass casualty event (friendly fire) and the reality of a number of small casualty events in which brave Americans are losing their lives.

Would there have been thoughts to cancel the whole exercise after the first incident?

No - this is war. Train hard and fight easy - that remains the mantra of successful militaries. One casualty in training might save you 100 in combat. There is no time to put things on hold, have a review and another practice. The training exercises need to get the American military to the point where they can win on D-Day.

HMS Azalea. Photo Royal Navy

The second incident came on April 28, when participating crews, soldiers and ships were attacked by German E-Boats. How did the day unfold?

8 LSTs departed harbours on the South Devon Coast on 27 April, forming up in convoy with HMS Azalea (flower class corvette). They proceeded around Lyme Bay off the coast of Dorset during the night of 27-28th April preparing for a landing on the morning of 28th April. At 0204 hours on 28th April the convoy was attacked with three vessels being torpedoed (two LST507 and LST531 sunk as a result. One further LST 289 made port despite substantial damage). The E-Boats retired back to Cherbourg.

Would the German E-Boats have known about the Exercise, or did they come upon the area by chance?

German E-Boats are constantly on the look out for convoys running along the UK coast. They put to sea when alerted to the presence of the convoy by radio transmissions which suggest that one is at sea. Those radio transmissions are intercepted and German naval intelligence sends out the mission. They don't know what kind of a convoy that they are looking for until they close with it.

What were the immediate implications for the American forces in the UK after the incident, both militarily and politically?

It is a shock and there is concern that the Germans might derive intelligence about the forthcoming invasion. They quickly come to the conclusion that the D-Day secret hasn't been compromised.

LST 511 off Utah Beach - the LST was one of those involved in Exercise Tiger. Photo US Navy

Is it true that the incident almost caused D-Day to be cancelled?

The losses of LSTs on Exercise Tiger brought the allied invasion fleet down to the bare minimum it needed for such vessels, but there was no question of cancelling D-Day. Within the US Navy there was concern that it might be necessary to use a battleship to "take out" the E-Boat base at Cherbourg in the hours before the landing, but the British argued that it would just give a 'heads up' to the Germans that something was about to happen. As a result the British and Americans strengthened security against the E-Boats on D-Day and left it at that - and it worked.

What changes were made to procedures and to ships after Slapton Sands to better protect those participating in the D-Day landings?

As well as the above, there also seems to have been better advice issued about wearing life preservers.

Many people didn't realize Exercise Tiger had happened until later years when word started to become public. Why did it take such time for the incident to become better understood?

Secrecy dies hard and when soldiers and sailors are told not to talk about something (for immediate operational reasons) they don't. No one comes along 20-30 years after the war to say "Its okay to talk about that incident now'.

Memorials are taking place this weekend at Slapton Sands to commemorate the 75th anniversary of Exercise Tiger, and those soldiers who lost their lives. If you'd like to read more about the Slapton Sands story, including the work of Laurie Bolton, Ken Small and his son, Dean, to preserve the memory, please do follow the below links. For more information on this weekend's memorial, please go to www.exercisetigermemorial.co.uk.

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