Operation Overlord Immediately after the Japanese attack on Pearl
Harbour the Allies created the "Combined Chiefs of Staff" (CCS)
comprising the United States Joint Chiefs of Staff and the British
Chiefs of Staff. Their function was to assist and advise President
Roosevelt and Prime Minister Churchill on the direction and conduct
of the war. The CCS confirmed a previous policy of "Germany first"
and, from March 1942, their planning group began work on an outline
plan for a full-scale invasion of Europe. They initially hoped to
invade Europe in 1943 but the realities of insufficient materials
and manpower, and the demands of other operations agreed upon,
delayed this effort until 1944 - this despite persistent agitation
from Stalin to open a second front to relieve pressure in the East.
The CCS planning group, taking into account the experience provided by the ill fated Dieppe raid, quickly
ruled out a frontal attack on a fortified port and looked for alternative landing sites. The requirements
for a suitable landing site were for it;
to be within range of fighter aircraft based in southern England, to have at least one major port within
easy reach, to have landing beaches suitable for prolonged support operations, with adequate exits and
backed by a good road network, to have beach defenses capable of being suppressed by naval bombardment or
bombing.
The planners decided the Normandy coast between Caen and Cherbourg met these requirements and they
prepared a basic outline paper which was later approved by the CCS British Lieutenant General Sir
Frederick Morgan was appointed, in March 1943, as Chief of Staff to the Supreme Allied Commander (COSSAC).
His assignment was to prepare detailed plans for an invasion of Europe to be conducted the following year.
Morgan was an excellent choice. In November 1942 he was a task force commander in the invasion of North
Africa and he had just completed the preliminary planning for the invasion of Sicily which was to take
place in July 1943.
The ultimate goal was the destruction of German forces and the defeat of Germany. Morgan had to work
backwards from that result to determine what manpower and material forces were required to complete the
task. There had never been an amphibious invasion of this size and Morgan and his staff had to plan the
detail of the operation – a monumental task. The eventual invasion plan was given the codename "Overlord".
~ The Assault Plan ~ American General Dwight D. Eisenhower was appointed to the post of Supreme Commander
in December 1943. With his subsequent selection of other senior commanders the original plan underwent
some fundamental modifications. The ground commander, during the initial assault phase and subsequent
beachhead build up, was British General Bernard Montgomery. Montgomery expanded the proposed invasion
frontage from about 25 miles to 50 miles and increased the allocation of initial assault troops from the 3
to 5 divisions. Additionally a further 3 divisions of paratroopers – 2 American airborne divisions and 1
British airborne division – were allocated. Their mission was to seize vital bridges and crossroad strongpoints at each end of the invasion area to protect the eastern and western flanks from counterattack
during the initial landings.
The assault force was divided into a western task force (American troops), landing on two beaches in the
western section of the invasion front, and an eastern task force (British and Canadian troops) allocated
to three beach areas in the eastern section. Commando and Ranger forces were also allocated to the initial
assault with responsibility to neutralize specific coastal strong-points thought to be too difficult for
regular infantry to tackle successfully.
The main D-Day objectives were for each assault force to secure their respective beachheads and to
progress inland. By D+1 they were to link up the beachheads into one continuous front. During D+2 to D+9
they were expected to gain enough depth to form a secure staging area for the substantial follow up
forces. Once sufficient strength had been built up a breakout towards Paris and the Rhine was planned. The
senior commanders knew, that from the outset, a race against the Germans would be in play. The Allies
would have to build up their forces, in the beachhead area, faster than the Germans could bring up a
strong counter attack force. To impede the movement of German men,
supplies and armour, road and rail communications across the north of
France were subjected to intensive bombing raids prior to the
landings.
On D-Day itself the conduct of the amphibious
landings benefited from the costly lessons
from previous raids and landings. Important
amongst these were extensive bomber, fighter
and naval bombardment support and improved
radio communications at all levels. A number
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of unique solutions to the problems of landing under fire, on heavily defended open beaches, were
developed. These were most likely used on the British and Canadian beaches where specialized armoured
units led the attack. An eccentric, former Major General Percy Hobart, who had been personally selected by
Churchill to modernize Britain’s tank program, developed so called "Funnies." These included the "flail
tank" whose rotating drum and chains cleared paths through mine fields and other adaptations designed to
clear tank obstacles and pill boxes.
In the absence of the early capture of a functioning harbour it was essential to provide for the safe
landing of thousands of tons of supplies and equipment each day during the period of build up. One planner
suggested that the invasion force should "take a harbour over with them." A similar idea had been
promulgated by Churchill during WW1. Twenty thousand workers laboured for eight months to construct an
ingenious solution to the challenge. The result of their labours became known as "Mulberry Harbours" which
were eventually installed at both American and British beaches.
The landings were planned to start at or near dawn. In addition Rommel's extensive beach obstacles further
narrowed options to a period of low tide or on a rising tide. It was during these periods that the beach
obstacles would be exposed and could be more easily "removed" by assault engineers. There was also a need
for sufficient moonlight on the night before the landings to assist the airborne forces in achieving their
objectives. These various factors gave the planners the rather limited choice of either June 5th, 6th or
7th as the earliest possible invasion dates. If the notoriously fickle Channel weather proved
uncooperative the next window of opportunity would be June 19th.
"It is my unshakeable decision to make this front impregnable against every enemy" - so said Hitler in a
speech he delivered in December 1941. He boasted, to the world, that Germany controlled the entire west
coast of Europe from the Arctic Ocean to the Bay of Biscay. He ordered the building of some 15,000 strongpoints which were to be manned by 300,000 troops. Construction officially started in early 1942. For 2
years a quarter of a million, mainly slave labourers, worked night and day. They used more than a million
tons of steel and poured over 20 million cubic yards of concrete. The heaviest concentration of defence
works was along the narrowest part of the English Channel between the Netherlands and Le Havre in
Normandy.
As it became obvious that the Allies were building up to an invasion, in November 1943 Hitler appointed
Field Marshall Rommel initially to the position of Inspector of Coastal Defences and later to the command
of Army Group B which occupied the channel coastal defences. He moved to France in December 1943 and
immediately started to apply his significant energy and experience to further improving the defences. He
planned to create an impassable zone, initially 100 meters deep, along the whole channel coast and to
eventually extend its depth to a kilometre by the laying of 200 million mines. He dramatically accelerated
the rate at which beach obstacles were constructed and, by May 11th, over half a million had been raised
along the channel foreshore and on likely glider and parachute landing zones behind the beaches.
Additionally some areas immediately behind the beaches were inundated with water to further inhibit any
movement off the beaches and to contain the attacker’s beachheads.
As a further preparation for a possible amphibious invasion in the west Hitler issued a decree – Fuhrer
Order 51 in November 1943. Rommel was well aware that the Allies supremacy in the air would inhibit
daytime movements once battle was joined – he had been subjected to this experience in North Africa. He
therefore planned to stop and contain the invaders at the water’s edge. Then he planned to have sufficient
Panzer (Armoured) divisions, closely available, to counter attack and overrun the beachheads before they
became established. From May onwards the Germans braced themselves for an attack they were sure would
come. They were puzzled when the relatively mild weather of May passed with no sign of the enemy and took
the opportunity to complete more obstacles on the beaches. Rommel was now confidant that his improved
"Atlantic Wall" would hold the enemy on the beaches. He was convinced that the Allies would attack on a
high tide – at dawn. These two conditions coincided for a few days around the middle of June.
What Rommel didn't know was that on May 17th General Eisenhower set the invasion date for June 5th.
However, in the event, bad weather caused a postponement of 24 hours. This was an unwelcome delay for the
combat ready force and even more so for those onboard ships recalled while at sea. However an improvement
in the weather saw the departure of the armada of over 5,000 ships. These included many kinds of landing
craft, troop transports, minesweepers, radar & communications vessels (Fighter Direction Tenders), escort
and bombardment naval vessels.
Q’S TO ANSWER ON A SEPARATE SHEET:(IN COMPLETE SENTENCES – DON’T’ HAVE TO
COPY THE QUESTION)
1. What did Hitler boast to the world in December of 1941?
2. Why was there a need for “moonlight” on the night before the landings?
3. Why was the invasion of Europe delayed in 1943?
4. What was the responsibility of Commando and Ranger forces on D-day?
5. Describe the “flail” tank physically and what it was designed for.
6. Why did Hitler flood (or “inundate with water”) areas behind beach heads?
7. What did Rommel’s experience in North Africa make him “well aware of?
8. For what purpose were the “Mulberry Harbours” constructed?
9. Why was Morgan an excellent choice for developing plans for D-day?
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