In order to carry out the trials, a mixed force of all arms was assembled consisting of infantry, tanks, tank destroyers, Assault Engineers and Ronson Flamethrowers. In support were field guns and 4.2” mortars and the RAF (smoke bombs). Certainly at the start, Brigadier Wales suffered from equipment shortages – for example he notes that the Exercise “started off with about 4 or 5 tanks, collected together from various places”. He eventually assembled a complete squadron. The final drill was built up from this low level and Brigadier Wales was well aware it was not final solution when the Exercise ended.
The Exercise was a series of trials, utilizing various equipments and techniques in the assault. Various drills and formations were tried; some worked, some did not. Trials were carried out during both daytime and nighttime. Brigadier Wales personally felt that there was no advantage of carrying out such operations at night and preferred daytime operations with the use of smoke. One War Diary of a unit taking part, the Princess Louise Fusiliers, does hint that night time trials did work quite well.
Brigadier Wales does give some idea of how the drill was practiced. The attackers were only given limited information – they did not know the location of every pillbox. They were however given an area in which to make a breach in the obstacle. The distance between each breach was only 100 yards.
Brigadier Wales assumed that each German Hedgehog was held by one or possibly two companies with supporting arms. He decided to employ a Battalion Group (on the new three company organization) for each Hedgehog. He split the assault into two phases:
- To breach the obstacle
- To destroy every German inside the Hedgehog.
Wales stressed that the destruction of the Hedgehog depended entirely on the success of breaching the obstacle.
The final method of assault developed during the trials was as follows:
This was to consist of the study of aerial photos and intelligence on the objective, followed by preliminary planning and rehearsals on a similar bit of ground in this country. On arrival in the beach head a brief recce should be carried out.
Preparation of Objective
This was to consist of an artillery concentration of H.E and if possible aerial bombing as well. This was to be followed by anti-tank gun fire against concrete defences accompanied by a machine gun barrage to cover the anti-tank guns and to dominate the enemy. This fire was to be maintained until the last possible moment, when the Assault groups passed through gaps created in the obstacle. If sufficient tanks were available they should be used to provide the anti-tank gun and machine gun fire, as they were mobile, less easily to knock out than anti-tank guns and could also provide their own smoke cover.
Complete Blanket of smoke
This could be provided by 4.2”, 3” and 2” mortars as well as the use of the RAF to drop smoke bombs. Brigadier Wales was of a strong opinion that smoke should be limited to the objective and be under the command of the battalion commander. An “area smoke” programme should not be used as it was considered that this could interfere with the battalion commanders carefully worked out plans. If an “area smoke” programme was to be used it should be restricted to allow the general deployment of a number of assault units then lifted to allow the battalion commander to introduce his own local plan.
Breaching of the obstacle under cover of smoke
This was to be carried out by two assault companies each making two breaches in the obstacle and passing one platoon group through each breach. The third platoon group of each company passes through either gap and swings right or left according to whether the company is the right or left company of the battalion group. This helped to widen the bridge head. Each platoon group then fights it way forward until it reaches the far side of the Hedgehog or is fought to a standstill. The third company of the battalion group was held in reserve and could be deployed against any part of the Hedgehog still holding out.
Above: Left - the breach of the obstacle and assualt (from "A Drill for the Assault on a Highly Defeloped Defended Locaility). Right - it is easy to guess where this drill was practised on the Kruschen Hedgehog due to highly eroded sections of the anti-tank ditch.
Composition of Battalion Group
This consisted of three assault company groups. The two forward assault company groups consisted of three platoon groups, the two leading platoon groups comprising of:
- One section of tanks (a section of tanks was normally three meaning the forth tank was found from a reserve section):
- Tank ‘A’ – tows the snake
- Tank ‘B’ – pushes and fires the snake
- Tank ‘C’ – carries the fascine and tows a R.E sledge
- Tank ‘D’ – acts as foster-mother and helps the Ronsons over the ditch
- Infantry platoon deployed in three sections in arrow head formation
- Assault Engineer section divided into two demolition parties for carrying out tasks inside the Hedgehog (e.g. to reduce concrete defence works that had not been knocked out by fire). An additional half section of Engineers would be carried in the assault tanks with a specific role in connection with breaching the obstacle (to assist in breaching, to widen and maintain the gaps created).
- One section of Ronsons
- Platoon HQ – which included the 2” mortar which could move up and give smoke support as required
The support company did not require a snake (hence only three tanks) or a fascine as the breach had already been made.
Right: The Assault Company
Method of Assault
As noted, the assault was to be carried out by two company groups, with one in reserve. Each assault company was to be split in to three platoon groups, each of the two lead groups were to make a breach in the obstacle.
The method of making the breach in Wales’ drill was as follows:
Tank ‘A’ tows the snake, dropping it within 20 or 30 yards of the obstacle. It then moves to a position on the flank and opens fire with its machine gun. Tank ‘B’ the pushes the Snake into place and fires it then moves to one side. Tank ‘C’ enters the gap created by the Snake, drops it fascine into the ditch and crosses over and attacks the enemy locality. Tank ‘D’ helps the Ronsons over the ditch, the Ronsons then disengage from the ‘foster-mother’ tank and go into the attack. Infantry and R.E then follow through the gap as close as possible to the Ronsons and go into the fight. Brigadier Wales thought that the infantry should be towed through the gap in the obstacle in a specially adapted armoured sledge. He reasoned that the smoke screen would ensure that enemy machine guns would fire on fixed lines but that anti-tank guns would not open fire unless they could see their target.
Brigadier Wales managed to get hold of the only Crocodile tank then in existence for the Exercise. He concluded that it was an excellent weapon and if available should be used instead of the Ronsons. He considered that they should be employed in troops of three, one troop in each platoon assault group. In addition each Crocodile tank should tow an armoured infantry sledge through the breach in the obstacle, the sledge being released from the tank when through the obstacle and the infantry then following close behind the tank.
The attack was to be supported by an artillery programme. Prior to the attack going in, anti-tank guns would engage all visible pillboxes while the field artillery would lay down a barrage on the enemy forward areas. As the attack went in, 4.2” and 3” mortars would fire a smoke barrage and the field artillery barrage would lift to the centre of the Hedgehog, while the anti-tank guns would cease fire. The Field Regt (25-pounders) taking part noted that on a final rehearsal for a demonstration on 9th April, 875 rounds of H.E were fired; on the date of the actual demonstration, 14th April, 1,043 rounds of HE were fired.
Above: Left - the Assault Company deployed for the assault. Right - the assault