The nature of the beach defences that sprang up in the summer of 1940, along with strategical thinking throughout the War, was in accordance with pre-War manuals.
“Engineer Training 1937” outlines both the startegical and tactical nature of beach defence. The strategical and tactical circumstances of the defence of a stretch of coast could vary considerably. Britain had insufficient troops to defend its long coast line. On the other hand not all stretches of coast were suited for landings either due to marine conditions (depth of water, currents, rocks etc.), difficulty of inland communications from the beaches to enemy objectives (for example marshes to rear of the beaches) or the need for the enemy to secure sea communications (i.e. distance from enemy naval and air bases). Thus should troops be distributed to cover all beaches suitable for landing or concentrated on those most likely to be subject to enemy landings? In either case early warning of any landing would always be necessary, by means of naval and air patrols, coastal watchers etc.
“Engineer Training 1937” notes that the arrangements required for the defence of beaches differed from the normal defensive systems in land operations. The defence of beaches favored a linear defence for two reasons:
The best opportunity to destroy the enemy was while he was at his greatest disadvantage, immediately before and during his landing on the beach.
Beaches favored the development of fire from a linear system.
The defence of beaches, as outlined in “Engineer Training 1937” was to consist of a linear series of defence works:
Strong (e.g. concrete) emplacements for guns, machine guns and searchlights, including command posts and shelters etc.
The construction of underwater obstacles on the beaches
The construction of obstacles on a wide front
The preparation of defended localities and other expedients for delaying the exploitation of a successful landing.
Improvement of communications for the use of forward troops and reserves.
These tactics are clearly laid out in Home Defence Forces, as can be seen in 11 Corps Defence Scheme of June 1940:
(a) All beaches on which a landing is possible will be defended.
(b) Obstacles will consist of:
(i) a wire obstacle which will be increased and strengthened as time and material become available.
(ii) concrete blocks to prevent exit of tanks from the beach or forshore.
(iii) beach mines.
(iv) anti-tank mines on exits from the beaches.
(v) underwater obstacles in the form of steel teeth and wire.
(c) The whole of these obstacles will be covered by fire, the maximum use being made of concrete pill-boxes to house anti-tank rifles and light automatics. Where beaches can be covered by direct gun fire 6 pdr guns in tank-proof pill-boxes will be installed as they become available”.
An additional consideration was the defences had to be prepared for attack from the rear following the successful use of airborne troops by Germany in the Spring of 1940.
11 Corps papers
Engineer Training 1937, HMSO, 1937