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British anti-invasion preparations of the Second World War entailed a large-scale division of
British anti-invasion preparations of the Second World War entailed a large-scale division of military
A military, also known collectively as armed forces, is a heavily armed, highly organized force primarily intended for warfare. It is typically authorized and maintained by a sovereign state, with its members identifiable by their distin ...
and civilian mobilisation in response to the threat of invasion (Operation Sea Lion
Operation Sea Lion, also written as Operation Sealion (german: Unternehmen Seelöwe), was Nazi Germany's code name for the plan for an invasion of the United Kingdom during the Battle of Britain in the Second World War. Following the Battle ...
) by German armed forces in 1940 and 1941. The British Army
The British Army is the principal land warfare force of the United Kingdom, a part of the British Armed Forces along with the Royal Navy and the Royal Air Force. , the British Army comprises 79,380 regular full-time personnel, 4,090 Gur ...
needed to recover from the defeat of the British Expeditionary Force in France, and 1.5 million men were enrolled as part-time soldiers in the Home Guard
Home guard is a title given to various military organizations at various times, with the implication of an emergency or military reserve force, reserve force raised for local defense.
The term "home guard" was first officially used in the America ...
. The rapid construction of field fortifications transformed much of the United Kingdom, especially southern England
Southern England, or the South of England, also known as the South, is an area of England consisting of its southernmost part, with cultural, economic and political differences from the Midlands and the North. Officially, the area includes G ...
, into a prepared battlefield. Sea Lion was never taken beyond the preliminary assembly of forces. Today, little remains of Britain's anti-invasion preparations, although reinforced concrete structures such as pillboxes and anti-tank cubes can still be commonly found, particularly in the coastal counties.
Political and military background
On 1 September 1939, Germany invaded Poland; two days later, Britain and France declared war onGermany
Germany, officially the Federal Republic of Germany (FRG),, is a country in Central Europe. It is the most populous member state of the European Union. Germany lies between the Baltic and North Sea to the north and the Alps to the sou ...
, launching the Second World War
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the World War II by country, vast majority of the world's countries—including all of the great power ...
. Within three weeks, the Red Army
The Workers' and Peasants' Red Army (Russian language, Russian: Рабо́че-крестья́нская Кра́сная армия),) often shortened to the Red Army, was the army and air force of the Russian Soviet Federative Socialist R ...
of the Soviet Union invaded the eastern regions of Poland in fulfilment of the secret Molotov–Ribbentrop Pact
The Molotov–Ribbentrop Pact was a non-aggression pact between Nazi Germany and the Soviet Union that enabled those powers to partition Poland between them. The pact was signed in Moscow on 23 August 1939 by German Foreign Minister Joachim von Ri ...
with Germany. A British Expeditionary Force (BEF) was sent to the Franco-Belgian border, but Britain and France did not take any direct action in support of the Poles. By 1 October, Poland had been completely overrun. There was little fighting over the months that followed. In a period known as the Phoney War
The Phoney War (french: Drôle de guerre; german: Sitzkrieg) was an eight-month period at the start of World War II, during which there was only one limited military land operation on the Western Front, when French troops invaded Germa ...
, soldiers on both sides trained for war and the French and British constructed and manned defences on the eastern borders of France.
However, the British War Cabinet became concerned about exaggerated intelligence reports, aided by German disinformation
Disinformation is false information deliberately spread to deceive people. It is sometimes confused with misinformation, which is false information but is not deliberate.
The English word ''disinformation'' comes from the application of the ...
, of large airborne forces which could be launched against Britain. At the insistence of Winston Churchill, then the First Lord of the Admiralty, a request was made that the Commander-in-Chief, Home Forces
Commander-in-Chief, Home Forces was a senior officer in the British Army during the First and Second World Wars. The role of the appointment was firstly to oversee the training and equipment of formations in preparation for their deployment o ...
, General Sir Walter Kirke, should prepare a plan to repel a large-scale invasion. Kirke presented his plan on 15 November 1939, known as "Plan Julius Caesar" or "Plan J-C" because of the code word
In communication, a code word is an element of a standardized code or Communications protocol, protocol. Each code word is assembled in accordance with the specific rules of the code and assigned a unique meaning. Code words are typically used for ...
"Julius" which would be used for a likely invasion and "Caesar" for an imminent invasion. Kirke, whose main responsibility was to reinforce the BEF in France, had very limited resources available, with six poorly trained and equipped Territorial Army divisions in England, two in Scotland and three more in reserve. With France still a powerful ally, Kirke believed that the eastern coasts of England and Scotland were the most vulnerable, with ports and airfields given priority.
On 9 April 1940, Germany invaded Denmark and Norway. This operation preempted Britain's own plans to invade Norway. Denmark surrendered immediately, and, after a short-lived attempt by the British to make a stand in the northern part of the country, Norway also fell. The invasion of Norway was a combined forces operation in which the German war machine projected its power across the sea; this German success would come to be seen by the British as a dire portent. On 7 and 8 May 1940, the Norway Debate in the British House of Commons revealed intense dissatisfaction with, and some outright hostility toward, the government of Prime Minister Neville Chamberlain
Arthur Neville Chamberlain (; 18 March 18699 November 1940) was a British politician of the Conservative Party who served as Prime Minister of the United Kingdom from May 1937 to May 1940. He is best known for his foreign policy of appeasem ...
. Two days later Chamberlain resigned and was succeeded by Churchill.
On 10 May 1940, Germany invaded France. By that time, the BEF consisted of 10 infantry
Infantry is a military specialization which engages in ground combat on foot. Infantry generally consists of light infantry, mountain infantry, motorized infantry & mechanized infantry, airborne infantry, air assault infantry, and m ...
divisions in three corps
Corps (; plural ''corps'' ; from French , from the Latin "body") is a term used for several different kinds of organization. A military innovation by Napoleon I, the formation was first named as such in 1805. The size of a corps varies great ...
, a tank
A tank is an armoured fighting vehicle intended as a primary offensive weapon in front-line ground combat. Tank designs are a balance of heavy firepower, strong armour, and good battlefield mobility provided by tracks and a powerful e ...
brigade and a Royal Air Force
The Royal Air Force (RAF) is the United Kingdom's air and space force. It was formed towards the end of the First World War on 1 April 1918, becoming the first independent air force in the world, by regrouping the Royal Flying Corps (RFC) an ...
detachment of around 500 aircraft. The BEF and the best French forces were pinned by the German attack into Belgium and the Netherlands, but were then outflanked by the main attack that came behind them through the Ardennes
The Ardennes (french: Ardenne ; nl, Ardennen ; german: Ardennen; wa, Årdene ; lb, Ardennen ), also known as the Ardennes Forest or Forest of Ardennes, is a region of extensive forests, rough terrain, rolling hills and ridges primarily in Be ...
Forest by highly mobile ''Panzer
This article deals with the tanks (german: panzer) serving in the German Army (''Deutsches Heer'') throughout history, such as the World War I tanks of the Imperial German Army, the interwar and World War II tanks of the Nazi German German Ar ...
'' divisions of the ''Wehrmacht
The ''Wehrmacht'' (, ) were the unified armed forces of Nazi Germany from 1935 to 1945. It consisted of the ''Heer'' (army), the ''Kriegsmarine'' (navy) and the ''Luftwaffe'' (air force). The designation "''Wehrmacht''" replaced the previou ...
'', overrunning any defences that could be improvised in their path. In fierce fighting, most of the BEF were able to avoid being surrounded by withdrawing to a small area around the French port of Dunkirk
Dunkirk (french: Dunkerque ; vls, label= French Flemish, Duunkerke; nl, Duinkerke(n) ; , ;) is a commune in the department of Nord in northern France.
The evacuation of British and 
The light tanks were mostly MkVIB and the cruiser tanks were A9 / A10 / A13. The infantry tanks included 27 obsolete Matilda MkIs but the rest were almost all the very capable
By July 1940 the situation had improved radically as all volunteers received uniforms and a modicum of training. 500,000 modern M1917 Enfield Rifles, 25,000 M1918 Browning Automatic Rifles and millions of rounds of ammunition were bought from the reserve stock of the U.S. armed forces, and rushed by special trains directly to Home Guard units. New weapons were developed that could be produced cheaply without consuming materials that were needed to produce armaments for the regular units. An early example was the No. 76 Special Incendiary Grenade, a glass bottle filled with highly flammable material of which more than six million were made.
The
In mid-1940, the principal concern of the Royal Air Force, together with elements of the
Although much larger in size and with many more ships, the Royal Navy, unlike the
The British engaged upon an extensive program of field fortification. On 27 May 1940 a Home Defence Executive was formed under General Sir Edmund Ironside, Commander-in-Chief, Home Forces, to organise the defence of Britain. At first defence arrangements were largely static and focused on the coastline (the coastal crust) and, in a classic example of defence in depth, on a series of inland anti-tank 'stop' lines. The stop lines were designated command, corps and divisional according to their status and the unit assigned to man them. The longest and most heavily fortified was the General Headquarters anti-tank line, GHQ Line. This was a line of pill boxes and anti-tank trenches that ran from Bristol to the south of London before passing to the east of the capital and running northwards to York. The GHQ line was intended to protect the capital and the industrial heartland of England. Another major line was the Taunton Stop Line, which defended against an advance from England's south-west peninsula. London and other major cities were ringed with inner and outer stop lines.
Military thinking shifted rapidly. Given the lack of equipment and properly trained men, Ironside had little choice but to adopt a strategy of static warfare, but it was soon perceived that this would not be sufficient. Ironside has been criticised for having a siege mentality, but some consider this unfair, as he is believed to have understood the limits of the stop lines and never expected them to hold out indefinitely.
Churchill was not satisfied with Ironside's progress, especially with the creation of a mobile reserve. Anthony Eden, the Secretary of State for War, suggested that Ironside should be replaced by General Alan Brooke (later Viscount Alanbrooke). On 17 July 1940 Churchill spent an afternoon with Brooke during which the general raised concerns about the defence of the country. Two days later Brooke was appointed to replace Ironside.
Brooke's appointment saw a change in focus away from Ironside's stop lines, with cement supplies limited Brooke ordered that its use be prioritised for beach defences and "nodal points". The nodal points, also called anti-tank islands or fortress towns, were focal points of the hedgehog defence and expected to hold out for up to seven days or until relieved.
The areas most vulnerable to an invasion were the south and east coasts of England. In all, a total of 153 Emergency Coastal Batteries were constructed in 1940 in addition to the existing coastal artillery installations, to protect ports and likely landing places. They were fitted with whatever guns were available, which mainly came from naval vessels scrapped since the end of the First World War. These included 6 inch (152 mm), 5.5 inch (140 mm), 4.7 inch (120 mm) and 4 inch (102 mm) guns. Some had little ammunition, sometimes as few as ten rounds apiece. At Dover, two 14 inch (356 mm) guns known as Winnie and Pooh were employed. There were also a few land-based torpedo batteries.
Beaches were blocked with entanglements of barbed wire, usually in the form of three coils of concertina wire fixed by metal posts, or a simple fence of straight wires supported on waist-high posts. The wire would also demarcate extensive
There were two types of socket roadblocks. The first comprised vertical lengths of railway line placed in sockets in the road and was known as hedgehogs. The second type comprised railway lines or RSJs bent or welded at around a 60° angle, known as hairpins. In both cases, prepared sockets about square were placed in the road, closed by covers when not in use, allowing traffic to pass normally.
Another removable roadblocking system used mines. The extant remains of such systems superficially resemble those of hedgehog or hairpin, but the pits are shallow: just deep enough to take an anti-tank mine. When not in use the sockets were filled with wooden plugs, allowing traffic to pass normally.
Bridges and other key points were prepared for demolition at short notice by preparing chambers filled with explosives. A Depth Charge Crater was a site in a road (usually at a junction) prepared with buried explosives that could be detonated to instantly form a deep crater as an anti-tank obstacle. The Canadian pipe mine (later known as the McNaughton Tube after General Andrew McNaughton) was a horizontally bored pipe packed with explosivesonce in place this could be used to instantly ruin a road or runway. Prepared demolitions had the advantage of being undetectable from the airthe enemy could not take any precautions against them, or plot a route of attack around them.
Crossing points in the defence networkbridges, tunnels and other weak spotswere called nodes or points of resistance. These were fortified with removable road blocks, barbed wire entanglements and land mines. These passive defences were overlooked by trench works, gun and mortar emplacements, and pillboxes. In places, entire villages were fortified using barriers of Admiralty scaffolding,
Open areas were considered vulnerable to invasion from the air: a landing by paratroops, glider-borne troops or powered aircraft which could land and take off again. Open areas with a straight length of or more within five miles (8 km) of the coast or an airfield were considered vulnerable. These were blocked by trenches or, more usually, by wooden or concrete obstacles, as well as old cars.
Securing an airstrip would be an important objective for the invader. Airfields, considered extremely vulnerable, were protected by trench works and pillboxes that faced inwards towards the runway, rather than outwards. Many of these fortifications were specified by the
In 1940, weapons were critically short; there was a particular scarcity of anti-tank weapons, many of which had been left in France. Ironside had only 170 2-pounder anti-tank guns but these were supplemented by 100 Hotchkiss 6-pounder guns dating from the First World War, improvised into the anti-tank role by the provision of solid shot. By the end of July 1940, an additional nine hundred 75 mm field guns had been received from the USthe British were desperate for any means of stopping armoured vehicles. The 
Early experiments with floating petroleum on the sea and igniting it were not entirely successful: the fuel was difficult to ignite, large quantities were required to cover even modest areas and the weapon was easily disrupted by waves. However, the potential was clear. By early 1941, a flame barrage technique was developed. Rather than attempting to ignite oil floating on water, nozzles were placed above high-water mark with pumps producing sufficient pressure to spray fuel, which produced a roaring wall of flame over, rather than on, the water. Such installations consumed considerable resources and although this weapon was impressive, its network of pipes was vulnerable to pre-landing bombardment; General Brooke did not consider it effective. Initially ambitious plans were cut back to cover just a few miles of beaches. The tests of some of these installations were observed by German aircraft; the British capitalised on this by dropping propaganda leaflets into occupied Europe referring to the effects of the petroleum weapons.
It seems likely the British would have used poison gas against troops on beaches. General Brooke, in an annotation to his published war diaries, stated that he "''... had every intention of using sprayed
The War Cabinet and the
''Churchill's Channel War: 1939–45''
, Osprey Publishing, * 10 September: Three destroyers found a convoy of invasion transports off Ostend and sank an escort vessel, two trawlers that were towing barges and one large barge. * 13 September: Three destroyers sent to bombard Ostend but the operation was cancelled due to bad weather. A further twelve destroyers swept parts of the French coast between Roches Douvres, Cherbourg, Boulogne and Cape Griz Nez. while an RAF bombing raid destroyed 80 barges at Ostend. * 15 September: Sergeant John Hannah gained the
The German Threat to Britain in World War Two.
By Dan Cruickshank BBC
''The Real Dad's Army''
nbsp;– TV documentary
Churchill's mysterious map
Pillboxesuk.co.uk
Defence of Britain database
* Landmarks centre of Great Britain {{DEFAULTSORT:British Anti-Invasion Preparations Of World War Ii 1940 in military history 1941 in military history 1940 in the United Kingdom 1941 in the United Kingdom Battle of Britain British World War II defensive lines Invasions of the United Kingdom Military history of the United Kingdom during World War II United Kingdom home front during World War II
French
French (french: français(e), link=no) may refer to:
* Something of, from, or related to France
** French language, which originated in France, and its various dialects and accents
** French people, a nation and ethnic group identified with Franc ...
forces ( Operation Dynamo) began on 26 May with air cover provided by the Royal Air Force at heavy cost. Over the following ten days, 338,226 French and British soldiers were evacuated to Britain. Most of the personnel were brought back to Britain, but many of the army's vehicles, tanks, guns, ammunition and heavy equipment and the RAF's ground equipment and stores were left behind in France. Some soldiers even returned without their rifles. A further 215,000 were evacuated from ports south of the Channel in the more organised Operation Aerial during June.
In June 1940 the British Army
The British Army is the principal land warfare force of the United Kingdom, a part of the British Armed Forces along with the Royal Navy and the Royal Air Force. , the British Army comprises 79,380 regular full-time personnel, 4,090 Gur ...
had 22 infantry divisions and one armoured division. The infantry divisions were, on average, at half strength, and had only one-sixth of their normal artillery. Over 600 medium guns, both 18/25 and 25 pounder
The Ordnance QF 25-pounder, or more simply 25-pounder or 25-pdr, was the major British field gun and howitzer during the Second World War. Its calibre is 3.45-inch (87.6 mm). It was introduced into service just before the war started, combin ...
s, and 280 howitzers were available, with a further one hundred 25 pounders manufactured in June. In addition, over 300 4.5-inch howitzers900 were modified in 1940 aloneand some 60 pounder howitzers and their modified 4.5-inch version as well as antiquated examples of the 6-inch howitzer were recovered from reserve after the loss of current models in France. These were augmented with several hundred additional 75-mm M1917 guns and their ammunition from the US. Some sources also state the British army was lacking in transport (just over 2,000 carriers were available, rising to over 3,000 by the end of July). There was a critical shortage of ammunition such that little could be spared for training.
In contrast, records show that the British possessed over 290 million rounds of .303 ammunition of various types on 7 June, rising to over 400 million in August. VII Corps was formed to control the Home Forces' general reserve, and included the 1st Armoured Division. In a reorganisation in July, the divisions with some degree of mobility were placed behind the "coastal crust" of defended beach areas from The Wash
The Wash is a rectangular bay and multiple estuary at the north-west corner of East Anglia on the East coast of England, where Norfolk meets Lincolnshire and both border the North Sea. One of Britain's broadest estuaries, it is fed by the river ...
to Newhaven in Sussex. The General Headquarters Reserve was expanded to two corps of the most capable units. VII Corps was based at Headley Court in Surrey to the south of London and comprised 1st Armoured and 1st Canadian Division
The 1st Canadian Division (French: ''1re Division du Canada'' ) is a joint operational command and control formation based at CFB Kingston, and falls under Canadian Joint Operations Command. It is a high-readiness unit, able to move on very shor ...
s with the 1st Army Tank Brigade. IV Corps was based at Latimer House to the north of London and comprised 2nd Armoured, 42nd and 43rd Infantry divisions. VII Corps also included a brigade, which had been diverted to England when on its way to Egypt, from the 2nd New Zealand Expeditionary Force. Two infantry brigades and corps troops including artillery, engineers and medical personnel from the Australian 6th Division were also deployed to the country between June 1940 and January 1941 as part of the Second Australian Imperial Force in the United Kingdom.
The number of tanks in Britain increased rapidly between June and September 1940 (mid-September being the theoretical planned date for the launch of Operation Sea Lion) as follows:
These figures do not include training tanks or tanks under repair.
The light tanks were mostly MkVIB and the cruiser tanks were A9 / A10 / A13. The infantry tanks included 27 obsolete Matilda MkIs but the rest were almost all the very capable Matilda II
The Infantry Tank Mark II, best known as the Matilda, was a British infantry tank of the Second World War.Jentz, p. 11.
The design began as the A12 specification in 1936, as a gun-armed counterpart to the first British infantry tank, the mach ...
. The first Valentine infantry tanks were delivered in May 1940 for trials and 109 had been built by the end of September. In the immediate aftermath of Dunkirk some tank regiments, such as the 4th/7th Royal Dragoon Guards
The 4th/7th Royal Dragoon Guards was a cavalry regiment of the British Army formed in 1922. It served in the Second World War. However following the reduction of forces at the end of the Cold War and proposals contained in the Options for Change ...
, were expected to go into action as infantry armed with little more than rifles and light machine guns. In June 1940 the regiment received the Beaverette
Standard Car 4x2, or Car Armoured Light Standard, better known as the Beaverette, was a British improvised armoured car produced during the Second World War.
History
The first version of the vehicle was built in 1940 by Standard Motor Company at ...
, an improvised armoured car developed by order of the Minister of Aircraft Production Lord Beaverbrook, and former holiday coaches for use as personnel carriers. It did not receive tanks until April 1941 and then the obsolete Covenanter
Covenanters ( gd, Cùmhnantaich) were members of a 17th-century Scottish religious and political movement, who supported a Presbyterian Church of Scotland, and the primacy of its leaders in religious affairs. The name is derived from '' Covena ...
.
Churchill stated "in the last half of September we were able to bring into action on the south coast front sixteen divisions of high quality of which three were armoured divisions or their equivalent in brigades". It is significant that the British Government felt sufficiently confident in Britain's ability to repel an invasion (and in its tank production factories) that it sent 154 tanks (52 light, 52 cruiser and 50 infantry) to Egypt in mid-August. At this time, Britain's factories were almost matching Germany's output in tanks and, by 1941, they would surpass them.
Home Guard
On 14 May 1940, Secretary of State for WarAnthony Eden
Robert Anthony Eden, 1st Earl of Avon, (12 June 1897 – 14 January 1977) was a British Conservative Party politician who served as Prime Minister of the United Kingdom from 1955 until his resignation in 1957.
Achieving rapid pro ...
announced the creation of the Local Defence Volunteers (LDV)later to become known as the Home Guard. Far more men volunteered than the government expected and by the end of June, there were nearly 1.5 million volunteers. There were plenty of personnel for the defence of the country, but there were no uniforms (a simple armband had to suffice) and equipment was in critically short supply. At first, the Home Guard was armed with guns in private ownership, knives or bayonets fastened to poles, Molotov cocktails and improvised flamethrower
A flamethrower is a ranged incendiary device designed to project a controllable jet of fire. First deployed by the Byzantine Empire in the 7th century AD, flamethrowers saw use in modern times during World War I, and more widely in World Wa ...
s.
By July 1940 the situation had improved radically as all volunteers received uniforms and a modicum of training. 500,000 modern M1917 Enfield Rifles, 25,000 M1918 Browning Automatic Rifles and millions of rounds of ammunition were bought from the reserve stock of the U.S. armed forces, and rushed by special trains directly to Home Guard units. New weapons were developed that could be produced cheaply without consuming materials that were needed to produce armaments for the regular units. An early example was the No. 76 Special Incendiary Grenade, a glass bottle filled with highly flammable material of which more than six million were made.
The sticky bomb
The "Grenade, Hand, Anti-Tank No. 74", commonly known as the S.T. grenade or simply sticky bomb, was a British hand grenade designed and produced during the Second World War. The grenade was one of a number of anti-tank weapons developed for ...
was a glass flask filled with nitroglycerin and given an adhesive coating allowing it to be glued to a passing vehicle. In theory, it could be thrown, but in practice it would most likely need to be placedthumped against the target with sufficient force to stickrequiring courage and good fortune to be used effectively. An order for one million sticky bombs was placed in June 1940, but various problems delayed their distribution in large numbers until early 1941, and it is likely that fewer than 250,000 were produced.
A measure of mobility was provided by bicycles, motorcycles, private vehicles and horses. A few units were equipped with armoured cars, some of which were of standard design, but many were improvised locally from commercially available vehicles by the attachment of steel plates. By 1941 the Home Guard had been issued with a series of "sub-artillery", a term used to describe hastily produced and unconventional anti-tank or infantry support weapons, including the Blacker Bombard (an anti-tank spigot mortar), the Northover Projector (a black-powder mortar), and the Smith Gun (a small artillery gun that could be towed by a private motorcar).
Royal Air Force
In mid-1940, the principal concern of the Royal Air Force, together with elements of the Fleet Air Arm
The Fleet Air Arm (FAA) is one of the five fighting arms of the Royal Navy and is responsible for the delivery of naval air power both from land and at sea. The Fleet Air Arm operates the F-35 Lightning II for maritime strike, the AW159 Wil ...
, was to contest the control of British airspace with the German Luftwaffe
The ''Luftwaffe'' () was the aerial-warfare branch of the German '' Wehrmacht'' before and during World War II. Germany's military air arms during World War I, the '' Luftstreitkräfte'' of the Imperial Army and the '' Marine-Fliegerabt ...
. For the Germans, achieving at least local air superiority was an essential prerequisite to any invasion and might even break British morale, forcing them to sue for peace.
If the German air force had prevailed and attempted a landing, a much-reduced Royal Air Force would have been obliged to operate from airfields well away from the southeast of England. Any airfield that was in danger of being captured would have been made inoperable and there were plans to remove all portable equipment from vulnerable radar
Radar is a detection system that uses radio waves to determine the distance ('' ranging''), angle, and radial velocity of objects relative to the site. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, w ...
bases and completely destroy anything that could not be moved. Whatever was left of the RAF would have been committed to intercepting the invasion fleet in concert with the Royal Navyto fly in the presence of an enemy that enjoys air superiority is very dangerous. However, the RAF would have kept several advantages, such as being able to operate largely over friendly territory, as well as having the ability to fly for longer as, until the Germans were able to operate from airfields in England, ''Luftwaffe'' pilots would still have to fly significant distances to reach their operational area.
A contingency plan called Operation Banquet required all available aircraft to be committed to the defence. In the event of invasion almost anything that was not a fighter would be converted to a bomberstudent pilots, some in the very earliest stages of training, would use around 350 Tiger Moth
The de Havilland DH.82 Tiger Moth is a 1930s British biplane designed by Geoffrey de Havilland and built by the de Havilland Aircraft Company. It was operated by the Royal Air Force (RAF) and other operators as a primary trainer aircraft. ...
and Magister
Magister is Latin for "master" or "teacher". It may refer to:
Positions and titles
* Magister degree, an academic degree
* Magister equitum, or Master of the Horse
* Magister militum, a master of the soldiers
* Magister officiorum (''master of o ...
trainers to drop bombs from rudimentary bomb racks.
Shortly before the outbreak of the Second World War the Chain Home
Chain Home, or CH for short, was the codename for the ring of coastal Early Warning radar stations built by the Royal Air Force (RAF) before and during the Second World War to detect and track aircraft. Initially known as RDF, and given th ...
radar system began to be installed in the south of England, with three radar stations being operational by 1937. Although the German High Command suspected that the British may have been developing these systems, Zeppelin
A Zeppelin is a type of rigid airship named after the German inventor Count Ferdinand von Zeppelin () who pioneered rigid airship development at the beginning of the 20th century. Zeppelin's notions were first formulated in 1874Eckener 1938, ...
detection and evaluation flights had proved inconclusive. As a result, the Germans underestimated the effectiveness of the expanding Chain Home radar system, which became a vital piece of Britain's defensive capabilities during the Battle of Britain
The Battle of Britain, also known as the Air Battle for England (german: die Luftschlacht um England), was a military campaign of the Second World War, in which the Royal Air Force (RAF) and the Fleet Air Arm (FAA) of the Royal Navy defended ...
. By the start of the war, around 20 Chain Home stations had been built in the UK; to supplement these and detect aircraft at lower altitudes, the Chain Home Low was also being constructed.
Royal Navy
Although much larger in size and with many more ships, the Royal Navy, unlike the Kriegsmarine
The (, ) was the navy of Germany from 1935 to 1945. It superseded the Imperial German Navy of the German Empire (1871–1918) and the inter-war (1919–1935) of the Weimar Republic. The was one of three official branches, along with th ...
, had many commitments, including against Japan and guarding Scotland and Northern England. The Royal Navy could overwhelm any force that the German Navy could muster but would require time to get its forces in position since they were dispersed, partly because of these commitments and partly to reduce the risk of air attack. On 1 July 1940, one cruiser and 23 destroyers were committed to escort duties in the Western Approaches
The Western Approaches is an approximately rectangular area of the Atlantic Ocean lying immediately to the west of Ireland and parts of Great Britain. Its north and south boundaries are defined by the corresponding extremities of Britain. The c ...
, plus 12 destroyers and one cruiser on the Tyne Tyne may refer to:
__NOTOC__ Geography
* River Tyne, England
*Port of Tyne, the commercial docks in and around the River Tyne in Tyne and Wear, England
*River Tyne, Scotland
* River Tyne, a tributary of the South Esk River, Tasmania, Australia
Peop ...
and the aircraft carrier . More immediately available were ten destroyers at the south coast ports of Dover
Dover () is a town and major ferry port in Kent, South East England. It faces France across the Strait of Dover, the narrowest part of the English Channel at from Cap Gris Nez in France. It lies south-east of Canterbury and east of Maidstone ...
and Portsmouth
Portsmouth ( ) is a port and city status in the United Kingdom, city in the ceremonial county of Hampshire in southern England. The city of Portsmouth has been a Unitary authorities of England, unitary authority since 1 April 1997 and is admi ...
, a cruiser and three destroyers at Sheerness
Sheerness () is a town and civil parish beside the mouth of the River Medway on the north-west corner of the Isle of Sheppey in north Kent, England. With a population of 11,938, it is the second largest town on the island after the nearby tow ...
on the River Thames
The River Thames ( ), known alternatively in parts as the River Isis, is a river that flows through southern England including London. At , it is the longest river entirely in England and the second-longest in the United Kingdom, after the ...
, three cruisers and seven destroyers at the Humber
The Humber is a large tidal estuary on the east coast of Northern England. It is formed at Trent Falls, Faxfleet, by the confluence of the tidal rivers Ouse and Trent. From there to the North Sea, it forms part of the boundary betw ...
, nine destroyers at Harwich
Harwich is a town in Essex, England, and one of the Haven ports on the North Sea coast. It is in the Tendring district. Nearby places include Felixstowe to the north-east, Ipswich to the north-west, Colchester to the south-west and Clacton- ...
, and two cruisers at Rosyth
Rosyth ( gd, Ros Fhìobh, "headland of Fife") is a town on the Firth of Forth, south of the centre of Dunfermline. According to the census of 2011, the town has a population of 13,440.
The new town was founded as a Garden city-style subur ...
. The rest of the Home Fleet
The Home Fleet was a fleet of the Royal Navy that operated from the United Kingdom's territorial waters from 1902 with intervals until 1967. In 1967, it was merged with the Mediterranean Fleet creating the new Western Fleet.
Before the Fi ...
five battleships, three cruisers and nine destroyerswas based far to the north at Scapa Flow
Scapa Flow viewed from its eastern end in June 2009
Scapa Flow (; ) is a body of water in the Orkney Islands, Scotland, sheltered by the islands of Mainland, Graemsay, Burray,S. C. George, ''Jutland to Junkyard'', 1973. South Ronaldsay an ...
. There were, in addition, many corvettes, minesweepers, and other small vessels. By the end of July, a dozen additional destroyers were transferred from escort duties to the defence of the homeland, and more would join the Home Fleet shortly after.
At the end of August, the battleship was sent south to Rosyth for anti-invasion duties. She was joined on 13 September by her sister ship , the battlecruiser , three anti-aircraft cruisers and a destroyer flotilla. On 14 September, the old battleship was moved to Plymouth
Plymouth () is a port city and unitary authority in South West England. It is located on the south coast of Devon, approximately south-west of Exeter and south-west of London. It is bordered by Cornwall to the west and south-west.
Plymout ...
, also specifically in case of invasion. In addition to these major units, by the beginning of September the Royal Navy had stationed along the south coast of England between Plymouth and Harwich, 4 light cruisers and 57 destroyers tasked with repelling any invasion attempt, a force many times larger than the ships that the Germans had available as naval escorts.
Field fortifications
The British engaged upon an extensive program of field fortification. On 27 May 1940 a Home Defence Executive was formed under General Sir Edmund Ironside, Commander-in-Chief, Home Forces, to organise the defence of Britain. At first defence arrangements were largely static and focused on the coastline (the coastal crust) and, in a classic example of defence in depth, on a series of inland anti-tank 'stop' lines. The stop lines were designated command, corps and divisional according to their status and the unit assigned to man them. The longest and most heavily fortified was the General Headquarters anti-tank line, GHQ Line. This was a line of pill boxes and anti-tank trenches that ran from Bristol to the south of London before passing to the east of the capital and running northwards to York. The GHQ line was intended to protect the capital and the industrial heartland of England. Another major line was the Taunton Stop Line, which defended against an advance from England's south-west peninsula. London and other major cities were ringed with inner and outer stop lines.
Military thinking shifted rapidly. Given the lack of equipment and properly trained men, Ironside had little choice but to adopt a strategy of static warfare, but it was soon perceived that this would not be sufficient. Ironside has been criticised for having a siege mentality, but some consider this unfair, as he is believed to have understood the limits of the stop lines and never expected them to hold out indefinitely.
Churchill was not satisfied with Ironside's progress, especially with the creation of a mobile reserve. Anthony Eden, the Secretary of State for War, suggested that Ironside should be replaced by General Alan Brooke (later Viscount Alanbrooke). On 17 July 1940 Churchill spent an afternoon with Brooke during which the general raised concerns about the defence of the country. Two days later Brooke was appointed to replace Ironside.
Brooke's appointment saw a change in focus away from Ironside's stop lines, with cement supplies limited Brooke ordered that its use be prioritised for beach defences and "nodal points". The nodal points, also called anti-tank islands or fortress towns, were focal points of the hedgehog defence and expected to hold out for up to seven days or until relieved.
Coastal crust
The areas most vulnerable to an invasion were the south and east coasts of England. In all, a total of 153 Emergency Coastal Batteries were constructed in 1940 in addition to the existing coastal artillery installations, to protect ports and likely landing places. They were fitted with whatever guns were available, which mainly came from naval vessels scrapped since the end of the First World War. These included 6 inch (152 mm), 5.5 inch (140 mm), 4.7 inch (120 mm) and 4 inch (102 mm) guns. Some had little ammunition, sometimes as few as ten rounds apiece. At Dover, two 14 inch (356 mm) guns known as Winnie and Pooh were employed. There were also a few land-based torpedo batteries.
Beaches were blocked with entanglements of barbed wire, usually in the form of three coils of concertina wire fixed by metal posts, or a simple fence of straight wires supported on waist-high posts. The wire would also demarcate extensive minefield
A land mine is an explosive device concealed under or on the ground and designed to destroy or disable enemy targets, ranging from combatants to vehicles and tanks, as they pass over or near it. Such a device is typically detonated automati ...
s, with both anti-tank and anti-personnel mines on and behind the beaches. On many of the more remote beaches this combination of wire and mines represented the full extent of the passive defences.
Portions of Romney Marsh, which was the planned invasion site of Operation Sea Lion, were flooded and there were plans to flood more of the Marsh if the invasion were to materialise.
Piers, ideal for landing troops, and situated in large numbers along the south coast of England, were disassembled, blocked or otherwise destroyed. Many piers were not repaired until the late 1940s or early 1950s.
Where a barrier to tanks was required, Admiralty scaffolding (also known as beach scaffolding or obstacle Z.1) was constructed. Essentially, this was a fence of scaffolding tubes high and was placed at low water so that tanks could not get a good run at it. Admiralty scaffolding was deployed along hundreds of miles of vulnerable beaches.
The beaches themselves were overlooked by pillboxes of various types. These were sometimes placed low down to get maximum advantage from enfilading fire, whereas others were placed high up making them much harder to capture. Searchlights were installed at the coast to illuminate the sea surface and the beaches for artillery fire.
Many small islands and peninsulas were fortified to protect inlets and other strategic targets. In the Firth of Forth
The Firth of Forth () is the estuary, or firth, of several Scottish rivers including the River Forth. It meets the North Sea with Fife on the north coast and Lothian on the south.
Name
''Firth'' is a cognate of ''fjord'', a Norse word meanin ...
in east central Scotland, Inchgarvie was heavily fortified with several gun emplacements, which can still be seen. This provided invaluable defence from seaborne attacks on the Forth Bridge and Rosyth Dockyard
Rosyth Dockyard is a large naval dockyard on the Firth of Forth at Rosyth, Fife, Scotland, owned by Babcock Marine, which formerly undertook refitting of Royal Navy surface vessels and submarines. Before its privatisation in the 1990s it was ...
, approximately a mile upstream from the bridge. Further out to sea, Inchmickery, north of Edinburgh, was similarly fortified. The remnants of gun emplacements on the coast to the north, in North Queensferry, and south, in Dalmeny
Dalmeny ( gd, Dùn Mheinidh, IPA: t̪uːnˈvenɪʝ is a village and civil parish in Scotland. It is located on the south side of the Firth of Forth, southeast of South Queensferry and west of Edinburgh city centre. It lies within the tr ...
, of Inchmickery also remain.
Lines and islands
The primary purpose of the stop lines and the anti-tank islands that followed was to hold up the enemy, slowing progress and restricting the route of an attack. The need to prevent tanks from breaking through was of key importance. Consequently, the defences generally ran along pre-existing barriers to tanks, such as rivers and canals; railway embankments and cuttings; thick woods; and other natural obstacles. Where possible, usually well-drained land was allowed to flood, making the ground too soft to support even tracked vehicles. Thousands of miles of anti-tank ditches were dug, usually by mechanical excavators, but occasionally by hand. They were typically wide and deep and could be either trapezoidal or triangular in section with the defended side being especially steep and revetted with whatever material was available. Elsewhere, anti-tank barriers were made of massive reinforced concrete obstacles, either cubic, pyramidal or cylindrical. The cubes generally came in two sizes: high. In a few places, anti-tank walls were constructedessentially continuously abutted cubes. Large cylinders were made from a section of sewer pipe in diameter filled with concrete typically to a height of , frequently with a dome at the top. Smaller cylinders cast from concrete are also frequently found. Pimples, popularly known as Dragon's teeth, were pyramid-shaped concrete blocks designed specifically to counter tanks which, attempting to pass them, would climb up exposing vulnerable parts of the vehicle and possibly slip down with the tracks between the points. They ranged in size somewhat, but were typically high and about square at the base. There was also a conical form. Cubes, cylinders and pimples were deployed in long rows, often several rows deep, to form anti-tank barriers at beaches and inland. They were also used in smaller numbers to block roads. They frequently sported loops at the top for the attachment of barbed wire. There was also a tetrahedral orcaltrop
A caltrop (also known as caltrap, galtrop, cheval trap, galthrap, galtrap, calthrop, jackrock or crow's foot''Battle of Alesia'' (Caesar's conquest of Gaul in 52 BC), Battlefield Detectives program, (2006), rebroadcast: 2008-09-08 on History Cha ...
-shaped obstacle, although it seems these were rare.
Where natural anti-tank barriers needed only to be augmented, concrete or wooden posts sufficed.
Roads offered the enemy fast routes to their objectives and consequently they were blocked at strategic points. Many of the road-blocks formed by Ironside were semi-permanent. In many cases, Brooke had these removed altogether, as experience had shown they could be as much of an impediment to friends as to foes. Brooke favoured removable blocks.
The simplest of the removable roadblocks consisted of concrete anti-tank cylinders of various sizes but typically about high and in diameter; these could be manhandled into position as required. Anti-tank cylinders were to be used on roads, and other hard surfaces; deployed irregularly in five rows with bricks or kerbstones scattered nearby to stop the cylinders moving more than 2 ft (0.60m). Cylinders were often placed in front of socket roadblocks as an additional obstacle. One common type of removable anti-tank roadblock comprised a pair of massive concrete buttresses permanently installed at the roadside; these buttresses had holes and/or slots to accept horizontal railway lines or rolled steel joists (RSJs). Similar blocks were placed across railway tracks because tanks can move along railway lines almost as easily as they can along roads. A rare extant example. These blocks would be placed strategically where it was difficult for a vehicle to go aroundanti-tank obstacles and mines being positioned as requiredand they could be opened or closed within a matter of minutes.
There were two types of socket roadblocks. The first comprised vertical lengths of railway line placed in sockets in the road and was known as hedgehogs. The second type comprised railway lines or RSJs bent or welded at around a 60° angle, known as hairpins. In both cases, prepared sockets about square were placed in the road, closed by covers when not in use, allowing traffic to pass normally.
Another removable roadblocking system used mines. The extant remains of such systems superficially resemble those of hedgehog or hairpin, but the pits are shallow: just deep enough to take an anti-tank mine. When not in use the sockets were filled with wooden plugs, allowing traffic to pass normally.
Bridges and other key points were prepared for demolition at short notice by preparing chambers filled with explosives. A Depth Charge Crater was a site in a road (usually at a junction) prepared with buried explosives that could be detonated to instantly form a deep crater as an anti-tank obstacle. The Canadian pipe mine (later known as the McNaughton Tube after General Andrew McNaughton) was a horizontally bored pipe packed with explosivesonce in place this could be used to instantly ruin a road or runway. Prepared demolitions had the advantage of being undetectable from the airthe enemy could not take any precautions against them, or plot a route of attack around them.
Crossing points in the defence networkbridges, tunnels and other weak spotswere called nodes or points of resistance. These were fortified with removable road blocks, barbed wire entanglements and land mines. These passive defences were overlooked by trench works, gun and mortar emplacements, and pillboxes. In places, entire villages were fortified using barriers of Admiralty scaffolding, sandbag
A sandbag or dirtbag is a bag or sack made of hessian (burlap), polypropylene or other sturdy materials that is filled with sand or soil and used for such purposes as flood control, military fortification in trenches and bunkers, shielding gl ...
ged positions and loopholes in existing buildings.
Nodes were designated 'A', 'B' or 'C' depending upon how long they were expected to hold out. Home Guard troops were largely responsible for the defence of nodal points and other centres of resistance, such as towns and defended villages. Category 'A' nodal points and anti-tank islands were usually garrisoned by regular troops.
The rate of construction was frenetic: by the end of September 1940, 18,000 pillboxes and numerous other preparations had been completed. Some existing defences such as mediaeval castles and Napoleonic forts were augmented with modern additions such as dragon's teeth and pillboxes; some iron age forts housed anti-aircraft and observer positions. About 28,000 pillboxes and other hardened field fortifications were constructed in the United Kingdom of which about 6,500 still survive. Some defences were disguised and examples are known of pillboxes constructed to resemble haystacks, logpiles and innocuous buildings such as churches and railway stations.
Airfields and open areas
Open areas were considered vulnerable to invasion from the air: a landing by paratroops, glider-borne troops or powered aircraft which could land and take off again. Open areas with a straight length of or more within five miles (8 km) of the coast or an airfield were considered vulnerable. These were blocked by trenches or, more usually, by wooden or concrete obstacles, as well as old cars.
Securing an airstrip would be an important objective for the invader. Airfields, considered extremely vulnerable, were protected by trench works and pillboxes that faced inwards towards the runway, rather than outwards. Many of these fortifications were specified by the Air Ministry
The Air Ministry was a department of the Government of the United Kingdom with the responsibility of managing the affairs of the Royal Air Force, that existed from 1918 to 1964. It was under the political authority of the Secretary of State ...
and defensive designs were unique to airfieldsthese would not be expected to face heavy weapons so the degree of protection was less and there was more emphasis on all-round visibility and sweeping fields of fire. It was difficult to defend large open areas without creating impediments to the movement of friendly aircraft. Solutions to this problem included the pop-up Picket Hamilton forta light pillbox that could be lowered to ground level when the airfield was in use.
Another innovation was a mobile pillbox that could be driven out onto the airfield. This was known as the Bison
Bison are large bovines in the genus ''Bison'' (Greek: "wild ox" (bison)) within the tribe Bovini. Two extant and numerous extinct species are recognised.
Of the two surviving species, the American bison, ''B. bison'', found only in North ...
and consisted of a lorry with a concrete armoured cabin and a small concrete pillbox on the flat bed.
Constructed in Canada, a 'runway plough', assembled in Scotland, survives at Eglinton Country Park. It was purchased by the army in World War II to rip up aerodrome runways and railway lines, making them useless to the occupying forces, if an invasion took place. It was used at the old Eglinton Estate, which had been commandeered by the army, to provide its army operators with the necessary experience. It was hauled by a powerful Foden Trucks tractor, possibly via a pulley and cable system.Eglinton Country Park archive.
Other defensive measures
Other basic defensive measures included the removal of signposts, milestones (some had the carved details obscured with cement) and railway station signs, making it more likely that an enemy would become confused. Petrol pumps were removed fromservice stations
A filling station, also known as a gas station () or petrol station (), is a facility that sells fuel and engine lubricants for motor vehicles. The most common fuels sold in the 2010s were gasoline (or petrol) and diesel fuel.
Gasoline ...
near the coast and there were careful preparations for the destruction of those that were left. Detailed plans were made for destroying anything that might prove useful to the invader such as port facilities, key roads and rolling stock
The term rolling stock in the rail transport industry refers to railway vehicles, including both powered and unpowered vehicles: for example, locomotives, freight and passenger cars (or coaches), and non-revenue cars. Passenger vehicles can ...
. In certain areas, non-essential citizens were evacuated. In the county of Kent
Kent is a county in South East England and one of the home counties. It borders Greater London to the north-west, Surrey to the west and East Sussex to the south-west, and Essex to the north across the estuary of the River Thames; it faces ...
, 40% of the population was relocated; in East Anglia
East Anglia is an area in the East of England, often defined as including the counties of Norfolk, Suffolk and Cambridgeshire. The name derives from the Anglo-Saxon kingdom of the East Angles, a people whose name originated in Anglia, in ...
, the figure was 50%.
Perhaps most importantly, the population was told what was expected from them. In June 1940, the Ministry of Information published ''If the Invader Comes, what to doand how to do it''. It began:
The first instruction given quite emphatically is that, unless ordered to evacuate, "the order ... as.. to 'stay put'". The roads were not to be blocked by refugees. Further warnings were given not to believe rumours and not to spread them, to be distrustful of orders that might be faked and even to check that an officer giving orders really was British. Further: Britons were advised to keep calm and report anything suspicious quickly and accurately; deny useful things to the enemy such as food, fuel, maps or transport; be ready to block roadswhen ordered to do so"by felling trees, wiring them together or blocking the roads with cars"; to organise resistance at shops and factories; and, finally: "Think before you act. But think always of your country before you think of yourself".
On 13 June 1940, the ringing of church bells was banned; henceforth, they would only be rung by the military or the police to warn that an invasiongenerally meaning by parachutistswas in progress.
More than passive resistance was expectedor at least hoped forfrom the population. Churchill considered the formation of a Home Guard Reserve, given only an armband and basic training on the use of simple weapons, such as Molotov cocktails. The reserve would only have been expected to report for duty in an invasion. Later, Churchill wrote how he envisaged the use of the sticky bomb, "We had the picture in mind that devoted soldiers ''or civilians'' would run close up to the tank and even thrust the bomb upon it, though its explosion cost them their lives talics added for emphasis" The prime minister practised shooting, and told wife Clementine and daughter in law Pamela that he expected them each to kill one or two Germans. When Pamela protested that she did not know how to use a gun, Churchill told her to use a kitchen butcher knife as "You can always take a Hun with you". He later recorded how he intended to use the slogan " You can always take one with you."
In 1941, in towns and villages, invasion committees were formed to cooperate with the military and plan for the worst should their communities be isolated or occupied. The members of committees typically included representatives of the local council, the Air Raid Precautions service, the fire service, the police, the Women's Voluntary Service and the Home Guard, as well as officers for medicine, sanitation and food. The plans of these committees were kept in secret ''War Books'', although few remain. Detailed inventories of anything useful were kept: vehicles, animals and basic tools, and lists were made of contact details for key personnel. Plans were made for a wide range of emergencies, including improvised mortuaries and places to bury the dead. Instructions to the invasion committees stated: "... every citizen will regard it as his duty to hinder and frustrate the enemy and help our own forces by every means that ingenuity can devise and common sense suggest."
At the outbreak of the war there were around 60,000 police officers in the United Kingdom, including some 20,000 in London's Metropolitan Police. Many younger officers joined the armed forces and numbers were maintained by recruiting "war reserve" officers, special constables and by recalling retired officers. As well as their usual duties the police, who are a generally unarmed force in Britain, took on roles checking for enemy agents and arresting deserters.
On the same day as the Battle of Dunkirk, Scotland Yard issued a memorandum detailing the police use of firearms in wartime. This detailed the planned training for all officers in the use of pistols and revolvers, as it was decided that even though the police were non-combatant, they would provide armed guards at sites deemed a risk from enemy sabotage, and defend their own police stations from enemy attack. A supplementary secret memorandum of 29 May also required the police to carry out armed motorised patrols of 2–4 men, if invasion happened, though it noted the police were a non-combatant force and should primarily be carrying out law enforcement duties. These arrangements led to high level political discussions; on 1 August 1940 Lord Mottisone
John Edward Bernard Seely, 1st Baron Mottistone, (31 May 1868 – 7 November 1947), also known as Jack Seely, was a British Army general and politician. He was a Conservative Party (UK), Conservative Member of Parliament (United Kingdom), Mem ...
, a former cabinet minister, telephoned Churchill to advise that current police regulations would require officers to prevent British civilians resisting the German forces in occupied areas. Churchill considered this unacceptable and he wrote to the home secretary, John Anderson, and Lord Privy Seal, Clement Attlee
Clement Richard Attlee, 1st Earl Attlee, (3 January 18838 October 1967) was a British politician who served as Prime Minister of the United Kingdom from 1945 to 1951 and Leader of the Labour Party from 1935 to 1955. He was Deputy Prime Min ...
, asking for the regulations to be amended. Churchill wanted the police, ARP wardens and firemen to remain until the last troops withdrew from an area and suggested that such organisations might automatically become part of the military in case of invasion. The War Cabinet discussed the matter and on 12 August Churchill wrote again to the home secretary stating that the police and ARP wardens should be divided into two arms, combatant and non-combatant. The combatant portion would be armed and expected to fight alongside the Home Guard and regular forces and would withdraw with them as necessary. The non-combatant portion would remain in place under enemy occupation, but under orders not to assist the enemy in any way even to maintain order. These instructions were issued to the police by a memorandum from Anderson on 7 September, which stipulated that the non-combatant portion should be a minority and, where possible, made up of older men and those with families.
Because of the additional armed duties the number of firearms allocated to the police was increased. On 1 June 1940 the Metropolitan Police received 3,500 Canadian Ross Rifles of First World War vintage. A further 50 were issued to the London Fire Brigade and 100 to the Port of London Authority Police
The Port of Tilbury Police is a non- Home Office ports police force responsible for the Port of Tilbury, and Tilbury 2 owned by the Port of Tilbury London Ltd, a subsidiary of Forth Ports plc. The force consists of a Chief of Police, Police Inspe ...
. Some 73,000 rounds of .303 rifle ammunition were issued, together with tens of thousands of .22 rounds for small bore rifle and pistol training. By 1941 an additional 2,000 automatic pistols and 21,000 American lend-lease revolvers had been issued to the Metropolitan Police; from March 1942 all officers above the rank of inspector were routinely armed with .45 revolvers and twelve rounds of ammunition.
Guns, petroleum and poison
In 1940, weapons were critically short; there was a particular scarcity of anti-tank weapons, many of which had been left in France. Ironside had only 170 2-pounder anti-tank guns but these were supplemented by 100 Hotchkiss 6-pounder guns dating from the First World War, improvised into the anti-tank role by the provision of solid shot. By the end of July 1940, an additional nine hundred 75 mm field guns had been received from the USthe British were desperate for any means of stopping armoured vehicles. The Sten
The STEN (or Sten gun) is a family of British submachine guns chambered in 9×19mm which were used extensively by British and Commonwealth forces throughout World War II and the Korean War. They had a simple design and very low production cost ...
submachine gun was developed following the fall of France, to supplement the limited number of Thompson submachine guns obtained from the United States.
One of the few resources not in short supply was petroleum oil; supplies intended for Europe were filling British storage facilities. Considerable effort and enthusiasm was put into making use of petroleum products as a weapon of war. The Army had not had flame-throwers since the First World War, but a significant number were improvised from pressure greasing equipment acquired from automotive repair garages. Although limited in range, they were reasonably effective.
A mobile flame trap comprised surplus bulk storage tanks on trucks, the contents of which could be hosed into a sunken road and ignited. A static flame trap was prepared with perforated pipes running down the side of a road connected to a elevated tank; some 200 of these traps were installed. Usually, gravity sufficed but in a few cases a pump assisted in spraying the mixture of oil and petrol.
A flame fougasse comprised a 40-gallon light steel drum filled with petroleum mixture and a small, electrically detonated explosive. This was dug into the roadside with a substantial overburden and camouflaged. Ammonal provided the propellant charge, it was placed behind the barrel and, when triggered, caused the barrel to rupture and shoot a jet of flame wide and long. They were usually deployed in batteries of four barrels and would be placed at a location such as a corner, steep incline or roadblock where vehicles would be obliged to slow.
Variants of the flame fougasse included the demigasse, a barrel on its side and left in the open with explosive buried underneath; and the hedge hopper: a barrel on end with explosive buried underneath a few inches deep and slightly off centre. On firing, the hedge hopper barrel was projected ten feet (3 m) into the air and over a hedge or wall behind which it had been hidden. 50,000 flame fougasse barrels were installed at 7,000 sites mostly in southern England and at a further 2,000 sites in Scotland.
Early experiments with floating petroleum on the sea and igniting it were not entirely successful: the fuel was difficult to ignite, large quantities were required to cover even modest areas and the weapon was easily disrupted by waves. However, the potential was clear. By early 1941, a flame barrage technique was developed. Rather than attempting to ignite oil floating on water, nozzles were placed above high-water mark with pumps producing sufficient pressure to spray fuel, which produced a roaring wall of flame over, rather than on, the water. Such installations consumed considerable resources and although this weapon was impressive, its network of pipes was vulnerable to pre-landing bombardment; General Brooke did not consider it effective. Initially ambitious plans were cut back to cover just a few miles of beaches. The tests of some of these installations were observed by German aircraft; the British capitalised on this by dropping propaganda leaflets into occupied Europe referring to the effects of the petroleum weapons.
It seems likely the British would have used poison gas against troops on beaches. General Brooke, in an annotation to his published war diaries, stated that he "''... had every intention of using sprayed mustard gas
Mustard gas or sulfur mustard is a chemical compound belonging to a family of cytotoxic and blister agents known as mustard agents. The name ''mustard gas'' is technically incorrect: the substance, when dispersed, is often not actually a gas, b ...
on the beaches''". Mustard gas was manufactured as well as chlorine
Chlorine is a chemical element with the symbol Cl and atomic number 17. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate between them. Chlorine is ...
, phosgene
Phosgene is the organic chemical compound with the formula COCl2. It is a toxic, colorless gas; in low concentrations, its musty odor resembles that of freshly cut hay or grass. Phosgene is a valued and important industrial building block, es ...
and Paris Green. Poison gases were stored at key points for use by Bomber Command and in smaller quantities at many more airfields for use against the beaches. Bombers and crop sprayers would spray landing craft and beaches with mustard gas and Paris Green.
Deception and disinformation
In addition to hiding real weapons and fortifications, steps were taken to create the impression of the existence of defences that were not real. Drain pipes stood in place of real guns, dummy pillboxes were constructed, and uniformed mannequins kept an unblinkingvigil
A vigil, from the Latin ''vigilia'' meaning ''wakefulness'' (Greek: ''pannychis'', or ''agrypnia'' ), is a period of purposeful sleeplessness, an occasion for devotional watching, or an observance. The Italian word ''vigilia'' has become genera ...
.
Volunteers were encouraged to use anything that would delay the enemy. A young member of the Home Guard (LDV) recalled:
In 1938, a section funded by MI6 was created for propaganda, headed by Sir Campbell Stuart
Sir Campbell Arthur Stuart (5 July 1885 – 14 September 1972) was a Canadian newspaper magnate. He ran propaganda operations for the British during both World Wars.
Early life
In 1885 Campbell Arthur Stuart was born in Montreal, Canada to st ...
. It was allocated premises at Electra House and was dubbed Department EH. On 25 September 1939, the unit was mobilised to Woburn Abbey
Woburn Abbey (), occupying the east of the village of Woburn, Bedfordshire, England, is a country house, the family seat of the Duke of Bedford. Although it is still a family home to the current duke, it is open on specified days to visitors ...
where it joined a subversion team from MI6, known as Section D, and by July these teams became a part of the newly created Special Operations Executive
The Special Operations Executive (SOE) was a secret British World War II organisation. It was officially formed on 22 July 1940 under Minister of Economic Warfare Hugh Dalton, from the amalgamation of three existing secret organisations. Its pu ...
(SOE). These SOE elements went on to form the core of the Political Warfare Executive in 1941. Their task was to spread false rumours and conduct psychological warfare
Psychological warfare (PSYWAR), or the basic aspects of modern psychological operations (PsyOp), have been known by many other names or terms, including Military Information Support Operations ( MISO), Psy Ops, political warfare, "Hearts and ...
. Inspired by a demonstration of petroleum warfare, one false rumour stated that the British had a new bomb: dropped from an aircraft, it caused a thin film of volatile liquid to spread over the surface of the water which it then ignited. Such rumours were credible and rapidly spread. American broadcaster William Shirer
William Lawrence Shirer (; February 23, 1904 – December 28, 1993) was an American journalist and war correspondent. He wrote '' The Rise and Fall of the Third Reich'', a history of Nazi Germany that has been read by many and cited in scholarly ...
recorded large numbers of burns victims in Berlin; though it is not clear what he personally saw, it seems likely his reports were influenced by rumours. The interrogation of a Luftwaffe pilot revealed the existence of such weapons was common knowledge, and documents found after the war showed the German high command were deceived. The rumour seemed to take on a life of its own on both sides leading to persistent stories of a thwarted German invasion, in spite of official British denials. On 15 December 1940, ''The New York Times'' ran a story claiming that tens of thousands of German troops had been 'consumed by fire' in two failed invasion attempts.
Planned resistance
The War Office did not treat the threat of invasion seriously until the collapse of France in May 1940. TheSecret Intelligence Service
The Secret Intelligence Service (SIS), commonly known as MI6 ( Military Intelligence, Section 6), is the foreign intelligence service of the United Kingdom, tasked mainly with the covert overseas collection and analysis of human intellige ...
had, however, been making plans for this eventuality since February 1940, creating the core of a secret resistance network across the country. This remained in existence until at least 1943 and comprised both intelligence and sabotage units. In May 1940, SIS also began to distribute arms dumps and recruit for a larger civilian guerrilla organisation called the Home Defence Scheme. This was deeply resented by the War Office who created the Auxiliary Units as a more respectable military alternative.
Auxiliary Units were a specially trained and secret organisation that would act as uniformed commandos to attack the flanks and rear of an enemy advance. They were organised around a core of regular army 'scout sections', supported by patrols of 6–8 men recruited from the Home Guard. Although approval for the organisation had been given in June 1940, recruiting only began in early July. Each patrol was a self-contained cell, expected to be self-sufficient. There was, however, no means of communicating with them once they had gone to ground, which greatly reduced their strategic value. Each patrol was well-equipped and was provided with a concealed underground operational base, usually built in woodland and camouflaged. Auxiliary Units were only expected to operate during an organised military campaign, with an expected lifespan of 14 days. They were not, therefore, intended to operate as a long term resistance organisation. The latter was the responsibility of the Secret Intelligence Service Section VII, which would have only begun to expand its operations once the country had actually been occupied, thus confining knowledge of its existence only to those men and women who would have been available at the time.
In addition, the Auxiliary Units included a network of civilian Special Duties personnel, recruited to provide a short-term intelligence gathering service, spying on enemy formations and troop movements. Reports were to be collected from dead letter drops and, from 1941, relayed by civilian radio operators from secret locations. The wireless network only become operational from 1941 and was unlikely to survive more than a few days following invasion. Intelligence gathering after this period would be by the mobile patrols of the GHQ Liaison Unit ('Phantom'), which were staffed by skilled linguists and equipped with powerful wireless sets for direct communication with GHQ.
Offensive anti-invasion operations
The War Cabinet and the Chiefs of Staff Committee
The Chiefs of Staff Committee (CSC) is composed of the most senior military personnel in the British Armed Forces who advise on operational military matters and the preparation and conduct of military operations. The committee consists of the Ch ...
were not content to sit and wait for the Germans to make the first move; considerable efforts were made to attack, by air and sea, the enemy shipping which had been assembled in occupied ports between The Hague
The Hague ( ; nl, Den Haag or ) is a list of cities in the Netherlands by province, city and municipalities of the Netherlands, municipality of the Netherlands, situated on the west coast facing the North Sea. The Hague is the country's ad ...
and Cherbourg
Cherbourg (; , , ), nrf, Chèrbourg, ) is a former commune and subprefecture located at the northern end of the Cotentin peninsula in the northwestern French department of Manche. It was merged into the commune of Cherbourg-Octeville on 28 ...
, starting in July 1940. These attacks became known as the "Battle of the Barges". Some notable operations are shown below:
* 12 August: Five Handley Page Hampden
The Handley Page HP.52 Hampden is a British twin-engine medium bomber that was operated by the Royal Air Force (RAF). It was part of the trio of large twin-engine bombers procured for the RAF, joining the Armstrong Whitworth Whitley and Vickers ...
s attacked the Ladbergen Aqueduct on the Dortmund-Ems Canal. The waterway was blocked for ten days, impeding the movement of barges towards the Channel ports.
* 8 September: Two cruisers and ten destroyers swept along the French coast and bombarded Boulogne
Boulogne-sur-Mer (; pcd, Boulonne-su-Mér; nl, Bonen; la, Gesoriacum or ''Bononia''), often called just Boulogne (, ), is a coastal city in Northern France. It is a sub-prefecture of the department of Pas-de-Calais. Boulogne lies on the C ...
harbour. In a separate operation, three Motor Torpedo Boats attacked a convoy of small vessels off Ostend
Ostend ( nl, Oostende, ; french: link=no, Ostende ; german: link=no, Ostende ; vls, Ostende) is a coastal city and municipality, located in the province of West Flanders in the Flemish Region of Belgium. It comprises the boroughs of Mariake ...
; two of the MTBs then entered the harbour and torpedoed two transport ships.Jackson, Robert (2013)''Churchill's Channel War: 1939–45''
, Osprey Publishing, * 10 September: Three destroyers found a convoy of invasion transports off Ostend and sank an escort vessel, two trawlers that were towing barges and one large barge. * 13 September: Three destroyers sent to bombard Ostend but the operation was cancelled due to bad weather. A further twelve destroyers swept parts of the French coast between Roches Douvres, Cherbourg, Boulogne and Cape Griz Nez. while an RAF bombing raid destroyed 80 barges at Ostend. * 15 September: Sergeant John Hannah gained the
Victoria Cross
The Victoria Cross (VC) is the highest and most prestigious award of the British honours system. It is awarded for valour "in the presence of the enemy" to members of the British Armed Forces and may be awarded posthumously. It was previously ...
during a raid by RAF bombers on invasion barges at Antwerp; four transport ships were damaged.
* 17 September: A major attack by Bomber Command on ports along the occupied coast. 84 barges were damaged at Dunkirk.
* 26 September: Operation Lucid
Operation Lucid was a British plan to use fire ships to attack invasion barges that were gathering in ports on the northern coast of France in preparation for a German invasion of Britain in 1940. The attack was initiated several times in Septe ...
, a plan to send fire ships into the harbours at Calais and Boulogne to destroy invasion barges, was abandoned when , one of the old tankers that were to be used, had engine failure and the other was suffering so many leaks that she was unfit for sea.
* 30 September: The monitor fired seventeen 15-inch shells onto Calais docks.
* 4 October: Second attempt at Operation Lucid, this time cancelled because of bad weather.
* 7 October: Third attempt at Lucid, cancelled when , the destroyer carrying the force commander, hit a mine and had to be towed home.
* 10–11 October: Operation Medium, the bombardment of invasion transports in Cherbourg. A concentrated RAF bombing raid during the night occupied the attention of German defences, allowing a Navy task force to approach to within gun range without detection. During the 18-minute bombardment, 120 15-inch shells were fired by the battleship HMS ''Revenge'', and a total of 801 4.7-inch shells were fired by her escorting destroyers. German coastal artillery
Coastal artillery is the branch of the armed forces concerned with operating anti-ship artillery or fixed gun batteries in coastal fortifications.
From the Middle Ages until World War II, coastal artillery and naval artillery in the form o ...
replied for 30 minutes without hitting any of the warships.
Between 15 July and 21 September, German sources stated that 21 transport vessels and 214 barges had been damaged by British air raids. These figures may have been under-reported.
The threat recedes
After the evacuation of Dunkirk, people believed that the threatened invasion could come at almost any time. Churchill was at times personally pessimistic about Britain's chances for victory, telling Hastings Ismay on 12 June 1940 that " u and I will be dead in three months' time". German preparations would require at least a few weeks, but all defensive precautions were made with an extreme sense of urgency. In mid-1940, an invasion attempt could have occurred at any time, but some times were more likely than others: the phase of the moon, the tides and, most of all, the weather were considerations. The weather usually deteriorates significantly after September, but an October landing was not out of the question. On 3 October, General Brooke wrote in his diary: "Still no invasion! I am beginning to think that the Germans may after all not attempt it. And yet! I have the horrid thought that he may still bring off some surprise on us." The Battle of Britain had been won, and on 12 October 1940, unknown to the British, Hitler rescheduled Sea Lion for early 1941. By then, the state of Britain's defences had much improved, with many more trained and equipped men becoming available and field fortifications reaching a high state of readiness. With national confidence rising, Prime Minister Churchill was able to say: "We are waiting for the long promised invasion. So are the fishes ..." When Germany invaded the Soviet Union, on 22 June 1941, it came to be seen as unlikely that there would be any attempted landing as long as that conflict was undecidedfrom the British point of view at the time, the matter hung in the balance. In July 1941, construction of field fortifications was greatly reduced and concentration given to the possibility of a raid in force rather than a full-scale invasion. On 7 December 1941, a Japanese carrier fleet launched a surprise air attack on the American fleet at Pearl Harbor; the United States entered the war on Britain's side. With America's '' Germany first'' strategic policy, resources flooded into the UK, effectively ending the danger of invasion after two years. In 1944, the British Army retained an "abnormally large force of over 100,000 men for defence of the United Kingdom and other contingencies which could have been used in Normandy" according to American historian Carlo d'Este.Effectiveness
General Brooke frequently confided his concerns to his private diary. When published, he included additional annotations written many years later: The question of whether the defences would have been effective in invasion is vexed. In mid-1940, the preparations relied heavily upon field fortifications. The First World War made it clear that assaulting prepared defences with infantry was deadly and difficult, but similar preparations in Belgium had been overrun by well-equipped German Panzer divisions in the early weeks of 1940 and with so many armaments left at Dunkirk, British forces were woefully ill-equipped to take on German armour. On the other hand, while British preparations for defence were ''ad hoc'', so were the German invasion plans: a fleet of 2,000 converted barges and other vessels had been hurriedly made available and their fitness was debatable; in any case, the Germans could not land troops with all their heavy equipment. Until the Germans captured a port, ''both'' armies would have been short of tanks and heavy guns. The later experiences of the Canadian Army during the disastrous Dieppe Raid of 1942, American forces onOmaha Beach
Omaha Beach was one of five beach landing sectors designated for the amphibious assault component of operation Overlord during the Second World War. On June 6, 1944, the Allies invaded German-occupied France with the Normandy landings. "Omaha" ...
on D-Day and taking on Japanese defenders on Pacific Islands
Collectively called the Pacific Islands, the islands in the Pacific Ocean are further categorized into three major island groups: Melanesia, Micronesia, and Polynesia. Depending on the context, the term ''Pacific Islands'' may refer to one of ...
showed that, under the right conditions, a defender could exact a terrible price from assaulting forces, significantly depleting and delaying enemy forces until reinforcements could be deployed to appropriate places via the sea and inland.
In the event of invasion, the Royal Navy would have sailed to the landing places, possibly taking several days. The German Kriegsmarine had, however, been severely depleted by the Norwegian campaign. It lost a heavy cruiser, a light cruiser, and almost a quarter of its destroyers; two heavy units, a Panzerschiff and a battlecruiser, were out of action due to torpedo damage. In late 1940, the Kriegsmarine was thus virtually bereft of heavy units to either provide gunfire support to a landing or to counter any intervention by the Royal Navy. It is now known that the Germans planned to land on the southern coast of England; one reason for this site was that the narrow seas of the English Channel
The English Channel, "The Sleeve"; nrf, la Maunche, "The Sleeve" ( Cotentinais) or (Jèrriais), ( Guernésiais), "The Channel"; br, Mor Breizh, "Sea of Brittany"; cy, Môr Udd, "Lord's Sea"; kw, Mor Bretannek, "British Sea"; nl, Het Kan ...
could be blocked with mines, submarines and torpedo boat
A torpedo boat is a relatively small and fast naval ship designed to carry torpedoes into battle. The first designs were steam-powered craft dedicated to ramming enemy ships with explosive spar torpedoes. Later evolutions launched variants of s ...
s. While German naval forces and the Luftwaffe could have extracted a high price from the Royal Navy, they could not have hoped to prevent interference with attempts to land a second wave of troops and supplies that would have been essential to German successeven if, by then, the Germans had captured a port essential for bringing in significant heavy equipment. In this scenario, British land forces would have faced the Germans on more equal terms than otherwise and it was only necessary to delay the German advance, preventing a collapse until the German land forces were, at least temporarily, isolated by the Royal Navy and then mounting a counterattack.
Scholarly consideration of the likely outcome of invasion, including the 1974 Royal Military Academy Sandhurst war game, agree that while German forces would have been able to land and gain a significant beachhead, intervention of the Royal Navy would have been decisive and, even with the most optimistic assumptions, the German army would not have penetrated further than GHQ Line and would have been defeated.Evans, 2004, the outcome is a major theme of this work, Evans gives emphasis to German logistical problems.
Following the failure to gain even local air superiority in the Battle of Britain, Operation Sea Lion was postponed indefinitely. Hitler and his generals were aware of the problems of an invasion. Hitler was not ideologically committed to a long war with Britain and many commentators suggest that German invasion plans were a feint never to be put into action.
While Britain may have been militarily secure in 1940, both sides were aware of the possibility of a political collapse. If the Germans had won the Battle of Britain, the Luftwaffe would have been able to strike anywhere in southern England and with the prospect of an invasion, the British government would have come under pressure to come to terms: the extensive anti-invasion preparations demonstrated to Germany and to the people of Britain that whatever happened in the air, the United Kingdom was both able and willing to defend itself.
See also
*Coats Mission
The Coats Mission was a special British army unit established in England in 1940 for the purpose of evacuating King George VI, Queen Elizabeth and their immediate family in the event of a German invasion of Britain during the Second World War. It ...
* Eastbourne Redoubt, home of the Combined Service Museum
* Dymchurch Redoubt
* Operation Lucid
Operation Lucid was a British plan to use fire ships to attack invasion barges that were gathering in ports on the northern coast of France in preparation for a German invasion of Britain in 1940. The attack was initiated several times in Septe ...
* Atlantic Wall
The Atlantic Wall (german: link=no, Atlantikwall) was an extensive system of coastal defences and fortifications built by Nazi Germany between 1942 and 1944 along the coast of continental Europe and Scandinavia as a defence against an anticip ...
* British County Divisions, regular infantry divisions raised for static and coastal defence duties
References
Footnotes
Notes
General references
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *Official documents
* ''Consolidated Instructions to Invasion Committees in England and Wales'' (July 1942) HM Government. *Collections
* * – an online archive of wartime memories contributed by members of the public and gathered by the BBC. * – subscription requiredFurther reading
* Bird, C. ''Silent Sentinels – A study of the fixed defences constructed in Norfolk during WWI and WWII'' (Dereham: The Larks Press 1999) * * * Foot, William. ''The Battlefields That Nearly Were. Defended England 1940'' (Stroud: Tempus Publishing 2006) * Kauffmann, J.E. and Jurga, Robert M. ''Fortress Europe: European Fortifications of World War II'', Da Capo Press, 2002. * * * * * Osborne, Mike. ''20th Century Defences in Britain'' (Stroud: Tempus Publishing 2003) * Ross, Stewart. ''World War II Britain. History from Buildings'' (London: Franklin Watts 2006)External links
The German Threat to Britain in World War Two.
By Dan Cruickshank BBC
''The Real Dad's Army''
nbsp;– TV documentary
Churchill's mysterious map
Pillboxesuk.co.uk
Defence of Britain database
* Landmarks centre of Great Britain {{DEFAULTSORT:British Anti-Invasion Preparations Of World War Ii 1940 in military history 1941 in military history 1940 in the United Kingdom 1941 in the United Kingdom Battle of Britain British World War II defensive lines Invasions of the United Kingdom Military history of the United Kingdom during World War II United Kingdom home front during World War II