In June 1943 Home Forces produced a provisional pamphlet “A Drill for The Assault on a Highly Defended Locality” based on the results from Exercise Kruschen. There were, however, some changes to Brigadier Wales’ drill. The number of tanks in each company group was increased; each of the two lead platoon groups now had two identical troops of tanks, the second troop to attempt the breach of the obstacle if the first failed. The pamphlet also laid down the minimum fire support needed to neutralize a Defended Locality (company size):
For H.E: twenty-four 25 pounders or 4.2” mortars
For smoke: eight 4.2” mortars in addition to those of the battalion and a large quantity of No. 77 grenades
Medium machine guns: twelve guns
As it was expected that the number of wheeled field guns and medium artillery landed during the early stages of the invasion would be low, assault teams would likely have to depend largely on 4.2” and 3” mortars which could be towed on sledges.
Right - the revised Assault Company
The drill was apparently discussed during Exercise Prelude (a TEWT to consider the problem of seizing and holding a bridgehead on the Continent) and some concerns were expressed:
It was not envisaged how sledges could be transported on landing craft tanks. Hence the 4.2” mortars may not be available when required. It was also noted that 4.2” mortars could not match the range or accuracy of field guns and infantry could not follow as close to mortar fire as they could to field gun barrages. It was felt essential that an adequate number of guns should support the assault and that in fact, these could be landed in sufficient numbers wherever tanks could be landed.
The drill envisaged the barrage lifting as the tanks breached the final obstacle; the infantry then followed on. It was considered that the infantry should be right up behind the supporting fire or they would never reach the objective.
Concern was expressed about tanks and infantry being able to cooperate closely under smoke; it was widely acknowledged that tanks and infantry required differing amounts of smoke. Concern was also raised about smoke cover being limited to the objective – this would loose any element of surprise. Smoke cover should also be used on the flanks. It was also considered that if the assault was to take place at night smoke should be used to mask enemy illumination.
It was questioned if tanks should be used in the initial assault as they would be vulnerable to anti-tank guns that had not been identified. It was also thought that only those tanks fitted with special devices (as being developed by 79th Armoured Division) should be used.
If anti-tank guns were to be used for direct fire against concrete defences it was acknowledged that these would likely have to be in addition to the normal allotment for defence – i.e. some concern as to if these would be actually available.
The infantry hated the idea of going into battle on sledges towed behind tanks – the Germans always concentrated fire on tanks, the control of infantry by junior commanders would be lost and dispersion of the infantry would be impossible.
It was felt that the breaching of minefields had not been adequately addressed and that no arrangements had been made to ensure that gapping tanks ever reached the obstacle. Apparently this was acknowledged during Exercise Kruschen and certainly Brigadier Wales does note that the detailed recce required to accurately ascertain the composition and extent of the obstacle would take a long time; Exercise Kruschen only took place on ground were the extent of the obstacle was known in advance to the attackers.
Dieppe showed that much better methods of assault landings would need to be developed if the invasion of France was to be successful. Exercise Kruschen was one of the first full scale set of trials to investigate ways of driving the Germans out of their concrete defences once the assault troops had landed. The key to Kruschen was cooperation between an all-arms assault force. Many of the techniques used in Kruschen had to some extent already been established. For example, the use of fascines by tanks dated back to the First War. A demonstration in November 1942 at Tunstall had already shown it was possible to push a Snake across anti-tank ditches. Drills for an infantry attack against a pillbox or strongpoint were already established. Kruschen combined all these elements, along with field artillery and the RAF, to investigate methods of attacking the most highly organized strongpoints likely to be encountered on the Atlantic Wall and Siegfried Line.
Exercise Kruschen was the first step in the experimental work that would ultimately lead to the AVRE under one unified command, the 79th Armoured Division. A Training Directive issued to Maj. Gen Hobart on April 10th 1943 stated:
“A technique for the assault on prepared defences was evolved in exercise “KRUSCHEN” and is to be issued as a pamphlet by this Headquarters to form the basis for training by all formations. This technique is, however, not complete. With the resources with which your units are gradually becoming equipped you will further develop the technique.”
Maj. Gen. Hobart was also ordered to construct replicas of enemy beach and inland defences in the Orfordness Battle Training Area, much as Brigadier Wales had done with Kruschen. The eventual outcome of this is well known and by the time of the Rhine crossing in March 1945 the 79th Armoured Division was the largest division in the British Army with over 1,500 tanks and other tracked vehicles!
Today, opinion on whether or not the use of the AVRE made a significant contribution to D Day is somewhat split. The two extreme views are that the AVRE saved countless lives, the other view being that it was an over-engineered solution. However where it probably did make an invaluable contribution was in the capture of the Channel Ports during operations in September 1944. The use of the AVRE’s in land based assaults against strongpoints, which defended these ports, undoubtedly saved many Canadian infantrymen’s lives as well as a great deal of time. It was to investigate this type of assault that Kruschen was ordered for back in December 1942.
Above: The outcome of all the training carried out in the UK from 1942 onwards. Left - anti-tank ditch crossed at Asnelles by fascine. Right - Assault troops and AVRE's form up for the assault on Le Havre