1939
SEPTEMBER
1939
German Codes - The
British Code & Cipher School moves to Bletchley Park,
England, the site of its magnificent successes breaking the German Enigma codes through the 'Ultra' programme . The school builds on the work of Polish and
later French code-breakers. By April 1940 the first low level
Luftwaffe codes are being deciphered. Many months follow
before comparable progress is made with Naval codes.
OCTOBER
1939
Americas - The Pan-American Conference establishes a 300-mile plus security
zone off the coasts of the Americas within which all hostile
action by the belligerent powers is forbidden.
NOVEMBER
1939
United States - The Neutrality Act is amended to allow the supply of arms
to belligerents on a 'cash and carry' basis. At the same time
American shipping is banned from the war zones.
Battle of the Atlantic - RAF
Coastal Command continues to patrol for U-boats on passage
into the Atlantic. Equal priority is now given to attacks,
but the crews are not trained and lack effective anti-submarine bombs.
Magnetic Mines - German
seaplanes lay the first magnetic mines
off the East Coast and drop one on tidal flats at
Shoeburyness in the Thames Estuary. It is defused on the 23rd
November and recovered by Lt-Cdr Ouvry (awarded the George
Cross), a vital step in the battle against a weapon which is
causing heavy losses and long shipping delays. In November
alone, 27 ships of 121,000 tons are sunk and for a time the
Thames Estuary is virtually closed to shipping.
Canadian Politics - William MacKenzie King, Prime Minister of Canada is reelected by a massive majority in
support of the government's war policies.
Merchant Shipping War -
Since September 1939, 430,000 tons of shipping have been sent
to the bottom by mines around the coasts of Britain - a loss
rate only second to U-boats. Now the Royal Navy slowly
counters magnetic mines with the introduction of ship-degaussing and 'LL' minesweeping gear. Although mines, contact, magnetic and
later acoustic remain a threat throughout the war, they never
again represent the danger of the first few months. Later in
the year, fast, heavily armed and efficient diesel-engined German E-boats commence attacks in coastal waters.
(Enemy or E-boat is the English term for German motor torpedo
boats or S-boats - "Schnell" - not to be confused
with the heavily armed torpedo boats or small destroyers with
their 'T' designation.)
APRIL
1940
Atomic Bomb - Just as
the “phoney war” ends in Europe (it never existed
at sea) the end of the war is foreshadowed when the British
government establishes the Maud Committee to oversee nuclear research. Similar steps have already been taken
in the United States, all of which eventually lead to an
operational atomic bomb.
German Codes - The
Bletchley Park Ultra programme is now decoding some Luftwaffe low-level Enigma
codes, partly because of poor German security procedures.
There is little evidence the hard-won information influences
the war over the next two violent months.
Air War - The first mines are laid by RAF Bomber Command off the
German and Danish coasts.
MAY
1940
British Politics -
Following a 10th May House of Commons debate on the Norwegian
campaign, Prime Minister Neville Chamberlain resigns and Winston Churchill assumes leadership.
JUNE
1940
AUGUST
1940
British Scientific
Developments - A British scientific mission carries to
the United States details of many important developments.
Amongst these is the recently invented cavity magnetron,
vital for short wavelength radar
and the eventual defeat of conventional U-boats. Also for the close-proximity fuse which becomes so important in the 1945
battles with Japanese Kamikaze aircraft. (The cavity
magnetron is now the heart of the common microwave cooker!)
Battle of
the Atlantic - Long
range Focke Wulf Kondor bombers start patrols off the coast of Ireland from a
base near Bordeaux. As well as spotting for U-boats they
attack and sink many ships, and continue to be a major threat
until the introduction of ship-borne aircraft in late 1941
starts to counteract them.
Royal Navy Codes - These
are changed and for the first time RN operational signals are secure from German interception
and decoding. it will be another three years before the convoy codes are made safe from the German
SEPTEMBER
1940
United States - After
months of negotiations, a "Ships-for-Bases" agreement is announced on the 5th for
the transfer of 50 old but valuable US destroyers to the
Royal Navy in exchange for British bases in Newfoundland,
Bermuda, the West lndies and British Guiana. The first of the
"flushdeckers" arrive in Britain towards the end of
the month.
Battle of
the Atlantic - The
German decoding B-Service is
instrumental in directing U-boats to convoys, where they hold
the advantage as they manoeuvre on the surface between the
merchantmen and escorts. Radar is urgently needed so the escorts can detect the
U-boats, force them to dive and lose their speed advantage.
Then start hunting them with ASDIC.
Axis Powers - Germany,
Italy and Japan sign the Tripartite Pact in Berlin on the 27th. They agree to jointly
oppose any country joining the Allies at war - by which they
mean the United States.
NOVEMBER
1940
United States - Franklin D. Roosevelt is elected to an unprecedented third
term of office as President of the United States.
Battle of
the Atlantic - Important
steps are taken in the air war when an RAF Sunderland
equipped with 1.5m wavelength anti-surface vessel (ASV) radar locates a U-boat. This is the first
success of its kind with a system that is mainly effective by
day; contact is lost within two miles of the target. It is
the addition of the Leigh light that will turn it into a
powerful night-time weapon as well. Now Coastal Command is
using
depth charges instead of
ineffective A/S bombs.
Merchant
Shipping War - Losses due to air attack and mines remain
a major problem. Aircraft and E-boats have now added acoustic mines to the magnetic and moored contact
mines in their armoury, but they never match up to the threat
the magnetic mines represented a year earlier.
MARCH
1941
United States - The Lend-Lease Bill is passed into law. Britain and her
Allies will be able to receive American arms and supplies
without immediate payment.
Battle of
the Atlantic - On 6th
March 1941, faced with the mortal threat of the German U-boat
and aircraft offensive in the Atlantic, Winston Churchill
issues his famous Battle of the Atlantic directive. Catapult armed
merchantmen (CAM) are to
be fitted out, merchant ships equipped with AA weapons as a
first priority, and more Coastal Command squadrons formed and
fitted with
radar. Port and dockyard
congestion is to be dealt with and the defence of ports
greatly improved.
Merchant Shipping War - Royal
Navy motor
gun-boats (MGB's) are
entering service to combat E-boat attacks on East Coast
convoys. Improved motor torpedo boats (MTBs)
are also being built to attack German coastal shipping. This
marks the first step in the building up of Coastal Forces.
Battle
of Cape Matapan - As ships of the Mediterranean Fleet cover troop movements to
Greece, 'Ultra'
intelligence is received
reporting the sailing of an Italian battlefleet with one
battleship, six heavy and two light cruisers plus destroyers
to attack the convoy routes. In the battle that follows,
Italian battleship "Vittorio Veneto" is damaged and heavy cruisers "FIUME",
"ZARA","POLA" and destroyers "ALFIERI" and "CARDUCCI" sunk for the loss of one Royal Navy aircraft.
Eastern Europe and Balkans
- Bulgaria joins the Tripartite Pact on the 1st March and German troops march in. As
of now, only Yugoslavia in the Balkans retains
national independence for a few days more. On the 25th
Yugoslavia joins the Tripartite Pact, but two days later an anti-Nazi coup topples
the Government.
APRIL
1941
Battle of
the Atlantic - Over the
next few months a number of long awaited ship types and
weapons start to be introduced. These will contribute
significantly to the eventual defeat of the U-boat.
(1) The first Auxiliary Fighter
Catapult Ships flying
the White Ensign and equipped with a single
'one-way' Hurricane are ready in April 1941. In May a
Hurricane is successfully launched from a Red Ensign
Catapult
Armed Merchantman
(CAM). CAM-ships are eventually superseded in 1943 by Merchant Aircraft
Carriers (MACs) -
merchantmen with full flightdecks, but sailing under the
Red Ensign and also carrying oil or grain.
(2) The final step in the
introduction of ship-borne aircraft into the Battle of
the Atlantic comes in June when the first escort carrier is ready for service. HMS
Audacity, converted from a German prize, has a short
life, but proves the great value of these vessels.
(3) New scientific
developments also start to play their part. In May the
first high definition, 10cm radar (Type 271) is installed in a corvette. Later
still, high
frequency, direction finding (HF/DF or 'Huff-Duff') is introduced to supplement the
work of the shore stations.
MAY
1941
Capture
of "U.110" and the German Enigma - South of Iceland, "U.110"
attacks Liverpool-out convoy OB318. Blown to the surface by
depth charges from corvette "Aubretia" on the 9th,
"U-110's" crew abandon ship, but she fails to go
down. A boarding party from destroyer "Bulldog",
led by Sub-Lt Balme, manages to get aboard. In a matter of
hours they transfer to safety "U-110's" entire Enigma package - coding
machine, code books, rotor settings and charts. The destroyer "Broadway"
stands by during this hazardous operation. Two days later "U-110" sinks on tow to Iceland, knowledge of
her capture having been withheld from the crew. The priceless
Enigma material represents one of the greatest intelligence
coup ever and is a major naval victory in its own right.
"U-110's" capture is
far and away the most successful of the attempts to capture
Enigma codes. In the March 1941 raid on the Norwegian Lofoten
Islands, spare coding rotors were
found. Then two days before the "U-110" triumph, a
cruiser force had tried to capture the weather trawler
"Munchen" off Iceland. At the end of the coming
June a similar operation is mounted against the
"Lauenberg". In both cases useful papers are taken but the real breakthrough
only comes with "U-110". Included with the material
captured are all rotor settings until the end of June 1941.
A number of codes are used
with Enigma. The U-boat one is 'Hydra', also used
by all ships in European waters. From the end of June,
Bletchley Park is able to decipher 'Hydra' right through
until the end of the war. Unfortunately the U-boats move
off this version to the new 'Triton' in February 1942.
The big ship 'Neptun' and Mediterranean 'Sud' and
'Medusa' codes are also soon broken.
Germany - Rudolf Hess, Hitler's deputy, flies to Britain on
his self-appointed peace mission. He is imprisoned in Britain
and disowned by Germany
JUNE
1941
Atomic Bomb - The
report on nuclear research by the Maud Committee leads to the
setting up of a development programme by Imperial Chemical
Industries. Code named 'Tube Alloys', it will oversee both atomic bomb and reactor work.
Battle of
the Atlantic - Following
the capture of the “U-100” Enigma material, the Royal Navy tracks down
the supply ships already in position to support the
"Bismarck" as well as other raiders and U-boats.
JULY
1941
Battle of
the Atlantic - Air cover
from Ireland, Iceland and Newfoundland is improving, but RAF
Coastal Command lacks the long-range aircraft to cover the mid-Atlantic gap. It is
in this area, some 800 miles long the U-boats are now
concentrating. Between January and June 1941, North Atlantic
merchant shipping losses had averaged 300,000 tons per month.
From July to December 1941 they are considerably down at an
average level of 104,000 tons. The reasons are varied -
evasive convoy routing and more effective aircraft deployment
from the
'Ultra’ work,
introduction of radars and high frequency
direction finding (HF/DF),
the availability of more escorts, and continuous escort. Operational research or "OR" (Operations research
in the US) using the simplest of mathematical techniques
makes great contributions to the analysis of more effective
convoy sizes, escort numbers, U-boat search techniques, depth
charge patterns and settings etc.
AUGUST
1941
Anglo-US Talks -
Winston Churchill crosses the Atlantic in battleship
"Prince of Wales" to meet President Roosevelt off
Argentia, Newfoundland between the 9th and 12th. Together
they draft the Atlantic Charter setting out their aims for war and peace. This
is signed by Britain, the United States and 13 Allied
governments in September.
SEPTEMBER
1941
Battle
of the Atlantic - Escort
carrier "Audacity" sails with UK/Gibraltar convoy
OG74. Her American-built
Martlet fighters shoot
down the first Kondor to fall victim to an escort carrier,
but U-boats still manage to sink five merchantmen. With major
new U-boat
construction programmes,
the increased number of submarines available to Adm Doenitz
(approaching 200 with 30 operational) allows him to establish
patrol lines in the Atlantic.
OCTOBER
1941
Japan - War Minister Gen Tojo becomes Japanese Prime Minister.
Australia -
The Country Party of former Prime Minister Robert Menzies who
resigned earlier in August falls from power. John Curtin and the Labour Party takes over.
NOVEMBER
1941
Battle of the
Atlantic - RAF aircraft of Coastal Command are now flying
regular patrols in the Bay of Biscay equipped with effective airborne depth charges and the long wavelength ASV radar. The first success is on the 30th by a
Whitley of No 502 Squadron. "U-206" on passage to the Mediterranean is detected and
sunk
DECEMBER
1941
Underwater Warfare -
Three
Italian human torpedoes launched
from submarine “Scire” (Cdr Borghese) penetrate
Alexandria harbour. Their charges badly damage battleships “Queen
Elizabeth” with Adm Cunningham on board and
“Valiant”. They both settle to the bottom and the
Mediterranean Fleet battle squadron ceases to exist.
As the Imperial Japanese
Navy goes to war, they
introduce the Allies to a secret and powerful weapon in
the 24in Long lance torpedo, with its far heavier warhead and range
than any other.
