Germany would have had the advantage in manoeuvre but this was abandoned in favour of rigid coastal defences. There was to be no freedom of movement to operate on the Western Front – it was forbidden for the Staff in operational planning to consider the interior of France as a battlefield or to study the probable movements of the enemy after a hypothetical breakthrough. As Hitler put it, the soldier’s proper business “was to stand and be killed in his defenses” and not fight a mobile war.
The defences were to be well fortified in places that the German High Command suspected the Allies would make landings, especially at Cap Gris Nez, the mouth of the Seine, the northern shoulder of the Cotentin peninsula, the Channel Islands, Brest and L’Orient. Some areas were to be made into “the mightiest fortresses” (Festung) in an eight year plan (e.g the Pas de Calais and the Channel Islands of Guernsey, Jersey and Sark). However the front was so long that the majority of the defence could only be arranged by a system of Strongpoints (Stutzpunkt). The Germans placed great reliance on artillery of all calibers to cover the frontage between strongpoints.
Right: Atlantic Wall - 1943
The construction of the defences along the coast was continually hampered by a lack of material and labour as priority was given to the defended ports (especially those with U-boat pens) and later on to the construction of the V1 launches sites. Towards the end of 1943, Field Marshall Rommel on orders from Hitler inspected the defences in the West from Denmark to Brittany. Rommel believed that once ashore and covered by naval and air fire, it would be difficult, if not impossible, to throw back the enemy into the sea. He therefore believed the defences should be as strong as possible and as many defence troops committed as possible in the beach defences, with reserves located on the coast and incorporated into the defence. Rommel was alarmed at the state of defences away from the port fortresses. He immediately ordered the large-scale emplacement of obstacles along the coast, submerged at high tide and above water at low tide, to make the landing of enemy craft as difficult as possible, if not impossible. Airborne troops landing in the rear were to be prevented by the placement of obstacles in the most threatened areas. In the spring of 1944 large areas of Normandy were flooded, including the Dives valley east of Caen, the area east of Isigny and the Douve valley northwest of Carentan, in order to upset Allied landing plans.
Most of the strongpoints had to be sited in the vicinity of the beach in order to meet the need that the main line of resistance was to be the high tide line. Priority was given to the provision of shell proof shelters for the garrison, anti-landing guns, anti-tank guns and command posts. By the time the invasion took place accommodation, although somewhat cramped was available for the majority of garrisons, although much only splinter proof due to the shortages in concrete. A continuous wire entanglement extended along the whole coast. The ground between individual strongpoints, and further inland, was mined (although the additional millions promised by Rommel never arrived and many of the existing mines were T mines laid two years ago and not guaranteed to be detonatable).
Most German commanders realized there were simply insufficient troops to hold such a rigid defence over the distance involved. German propaganda attempted to “build up” the strength of the Atlantic Wall, just as it had done with the West Wall in 1938. The strongest area of the Atlantic Wall, the heavy Offensive Batteries Group at Gap Gris Nez, was picked, and the impression given that the whole of the Atlantic Wall was of similar strength. Even the strongest areas were not as strong as was believed abroad. The installed guns in the mighty concrete works only had limited traverse and were unable to fire to the rear, on the land front. The guns were captured French, Belgium, Dutch, Polish, Russian and Yugoslavian of all types and calibers with a variety of ammunition, providing great logistical difficulties.
A German document, captured in Tunisia, outlined the fundamental German defence of the Coast of France. The document apparently comprised of notes taken at The German War College, although the date was unknown. The document confirms the overriding strategy as stated by Lt. Gen H Speidel.
The document states that the Coast was to be held as a series of strongpoints owing to the shortage of men. The principal of siting strongpoints in depth had to be given up. In organizing and siting of strongpoints, the following considerations were of primary importance:
- Where are there facilities to assist enemy landings?
- Where, beyond the landing areas are there good roads for rapid penetration to the interior of the country?
- Where are important installations that the enemy will want to seize or destroy?
- If sectors are ruled out for landings (e.g. difficult navigation, cliffs, wooded country, marsh, bogs etc) then the sectors where landings could take place will be all the more clearer.
Initially, strongpoints were to be constructed in areas only where there were favorable landing opportunities. In such areas they were often grouped into “Strongpoint Groups” (Stutzpunktgruppe).They should be sited so that weapons could sweep as large an area as possible and also to obtain observation over a wide an area of the sector as possible. A Strongpoint was garrisoned by a platoon to company and Strongpoint Groups by one to two companies. Typically the main weapons of each Strongpoint were two light machine guns, one heavy machine gun, one medium mortar, one 75mm field gun or four 47mm anti-tank guns. However, it was recognized that in a Coastal sector of such length, most strongpoints would be widely spaced. As time allowed it was planned to establish smaller posts between strongpoints, probably a rifle section or platoon with a light machine gun. These were known as “Resistance Nests” (Widerstandsnest).
The difference between a heavily defended sector and one not so heavily defended lay in the distance between the the strongpoints. In heavily defended areas they were about 1,000 yards apart, in less heavily defended areas about 2,000 to 3,000 yards apart. Allied Intelligence found no evidence of stongpoints built more than four miles back from the coast.
The battle was to be fought by defending strongpoints at all costs. Even concentrating on holding the most likely areas to be attacked would still spread the available troops too thinly. The importance of maintaining a reserve was impressed on local commanders, to deploy to the beach defences when the location of any attack became apparent. If such reserves were not available, then they had to be formed elsewhere – cooks, drivers or anyone that could be got hold of. They were not to man defences inland but were to reinforce the beach defences. Work had started on a second line, one to two kilometers in rear of the strongpoints consisting of strongpoints of field works and a second position, 10 to 20 kilometers in the rear of the coast , also consisting of field works.
Armoured counter attacks were to repel any enemy breakthrough. If these failed, then switch positions would have to be established in the rear and held until such a time that a more deliberate and successful counter attack could be organized.
Allied Intelligence was well aware of the German Plan of defence and noted that the Atlantic Wall was primarily concerned with the defence of ports with the following elements:
- To repel the initial assault – garrison and fortification of the coastline in all likely assault areas with an emphasis on those at or near ports. Great reliance was placed on artillery of all sorts.
- To repel the assault where it penetrates the defences of the shoreline, or, as the next stage, to defeat the initial buildup – this was to be achieved by mobile reserved echeloned in the rear.
- To prevent swift mechanized penetration for the purposes of isolating a port – obstacles in the rear of the shoreline, such as inundations, minefields, anti-tank ditches, covered to some extent by the fire of machine guns and anti-tank guns. This was not defence in depth – the shoreline was to be held at all costs. The defences in the rear where intended to delay any attack to give chance for the mobile reserves to act; they did not constitute a rear defensive zone
- To hold against attacks on ports from inland – garrisoning and fortification of ports to provide all round defence.
- To render ports useless after capture – demolition as a last resort.
In summary, the problem for the attacker would be to land while under fire from guns of all calibers and break through the beach defences. As the invasion progressed, obstacles of all kinds would be met, covered by fire. It would be essential to get through this “crust” before the armoured reserves held further back could be brought up.