The U-boat War, 1939-42
by John Barratt
On the outbreak of war in September 1939, Donitz had 39 U-boats stationed near
the main British shipping lanes. On the first day of hostilities, the liner Athenia
, was sunk by a U-boat commanded by Kapitan Franz-Julius Lemp. The German
commander had mistaken her for a troop-transport, but the deaths of a large
number of civilians, including Americans caused an immediate widespread outcry.
Hitler had in fact forbidden unrestricted submarine warfare of the kind which
had helped bring the USA into World War I, in the hope that Britain might,
after the fall of Poland, agree to a compromise peace.
Within a few weeks however, the Fuhrer accepted that there was no immediate
prospect of such an end to the war, and began lifting the restrictions on
submarine warfare. Britain responded by arming merchant ships and ordering them
to fire on U-boats on sight. In response Donitz authorised his commanders to
attack without warning any ship in convoy, or behaving in "a suspicious
manner", and within a designated zone around the British Isles unrestricted
submarine warfare was permitted, although neutral vessels, in theory, were not
supposed to be attacked.
During the first few months of the war there were rarely more than six or seven
U-boats at sea at any one time, and they mainly operated in the North East
Atlantic. The main concentration was in the Western Approaches to the English
Channel, where shipping lanes converged and the concentration of targets was
heaviest. Donitz was not as yet able to mount the kind of assault he had
ideally envisaged, for the demands of the other armed forces meant that far
fewer than the planned 29 new U-boats a month were being constructed. British
mining in the Channel forced U-boats to make their way to the operational zone
via a long detour around the British Isles, which greatly reduced the length of
time they could spend on station. The net result of all this was that Donitz
rarely had more than 20 boats available for Atlantic operations at any one
time, of which only about half a dozen would actually be on station.
Although such a small force could hardly bring Britain to her knees, they had a
number of individual successes. The British responded to the U-boat threat by
forming "hunter-killer" groups, sometimes built around an aircraft carrier, but
this policy went into sharp reverse when on September 19th 1939, the U-9 sank
the carrier "Courageous" in the Western Approaches, with the loss of 518 men.
This was followed quickly by another sharp blow, when on October 14th, Gunther
Prien, in U-47 , penetrated the supposedly impregnable defences of the British
Home Fleet's principal base at Scapa Flow, and sank the battleship Royal Oak
Learning from their experiences in World war I, the British had introduced a
limited convoy system from the outbreak of war, but both the fastest and
slowest ships were excluded, and left to sail independently. It was among these
"independents" that the U-boats scored their greatest success. By the end of
1939, only four ships out of a total of 5,756 sailing in convoy had been lost,
compared with the sinking of 102 "independents".
Even so, the shortage of convoy escorts, and the small number and limited range
of aircraft available to RAF Coastal Command made it fortunate that Donitz had
not, initially, enough U-boats to exploit his opponent's weakness. He would be
further frustrated in April 1940, when Hitler diverted the U-boats to take part
in "Operation Weserubung", the invasion of Norway, where the submarines' lack
of success was compounded by failings in the firing mechanism of their magnetic
torpedoes. In June these began to be replaced by a new type of contact
The "Happy Time", 1940-41
Despite all obstacles, the U-boats had sunk 224 ships totaling 1.3 million tons
between September 1939 and June 1940. And now the Fall of France improved their
prospects considerably, as the Germans took possession of French naval bases
along the Atlantic coast. The first French U-boat base was established in July
1940 at Lorient on the Bay of Biscay, and quickly was followed by bases at
Brest, St Nazaire and La Palice in Brittany. Use of these bases not only gave
the U-boats direct access to the Atlantic, but also shortened their journey to
the operational area by over 1,000 miles. This allowed a greater number of
U-boats to be at sea at any one time, and also to push their range much further
out into the Atlantic. A further impetus to German operations came with the
basing in Western France of long-range Focke-Wulfe 200 Kondor bomber
and reconnaissance aircraft. These aircraft, with a range of 2,200 miles, could
not only bomb Allied merchant ships, but more importantly, track their course
for waiting U-boats.
The British were facing other problems. The threat of a German invasion of
Britain during the summer of 1940 resulted in many destroyers being withdrawn
from convoy escort duties to wait in the Channel for Hitler's armada. The fall
of France, whilst easing matters for the U-boats, forced Britain, in order to
reduce attacks by the Luftwaffe, to shift her main convoy routes from the
Western Approaches and the English Channel to the North West Approaches and the
port of Liverpool. This not only imposed a great strain on Britain's western
ports, but also increased convoy journey times by up to 40%. Until new air
bases were eventually developed in Northern Ireland, and later in Iceland, the
lack of naval bases in now independent Eire, which had been available to the
Royal Navy in World War I, caused further problems.
On August 17th, Hitler, confident in the advantages which his U-boats now had,
declared a total blockade of Britain. The following months would later be
remembered by U-boat men as "the happy time". Though total merchant tonnage
lost in the autumn of 1940 was less than that of two years later, at 2,373,070
tons for the year it was still bad enough, and to make matters worse for the
Allies, it was achieved by an average of only 21 U-boats at sea at any one
time. During the year a total of 26 U-boats were lost.
The autumn of 1940 saw Donitz beginning to transfer the focus of his activities
to the mid-Atlantic, where he could attack weakly-escorted convoys beyond the
range of air support. September saw the first wolf-pack operation, when ten
U-boats intercepted two convoys off the west coast of Ireland, and sank 16
ships. The following month saw what would prove to be the single most
successful U-boat operation of the war, when a pack of 12 boats, in a four
-night operation, sank 32 merchant ships of a total 154,661 tons.
Donitz was not however satisfied with the rate of success being achieved.
Despite the somewhat unco-ordinated assistance provided by the Kondors
, Goring was unwilling to give much Luftwaffe support to Donitz, whom he saw as
a rival, and there were still insufficient U-boats available to approach the
rate of sinkings at which U-Boat Command was aiming. During 1940 German
shipyards were only producing U-boats at an average of four and a half vessels
a month. In 1941 this would be stepped up to a monthly average of 17 U-boats ,
but lengthy training needed for their crews meant that most would not be in
action until 1942.
In an effort to fill the gap, Donitz turned to Germany's Italian ally. Italian
submarines had proved less than impressive during the Spanish Civil War, and
they proved hardly more successful in Atlantic operations. Their commanders
were unfamiliar with German tactics and the wolf-pack concept, and from
December 1940, despairing of overcoming these problems, Donitz assigned the
Italians their own sector of the Atlantic and left them to their own devices.
Between September 1940 and July 1943 about 30 Italian submarines operated at
different times in the Atlantic, and sank a total of 105 Allied merchant ships
for the loss of 16 of their own vessels.
So far as the German U-boat effort was concerned, Donitz received an
encouraging boost early in 1941, when the first of the new longer-ranged Type
IX U-boats came into service, and commenced operations on the South Atlantic
The British were suffering severely from shortages of escort vessels. New
construction from British shipyards would not start to become available much
before 1942, and the 50 "Destroyers for Bases" supplied by the United States in
the summer of 1940 did not adequately bridge the gap. In the spring of 1941 the
United States agreed to assume responsibility for the protection of convoys
West of 26 degrees west Longitude. In July 1941, at British request, US troops
took over the garrisoning of Iceland, which was becoming an increasingly vital
naval and air base in the Battle of the Atlantic.
This increased American involvement in the Atlantic struggle could serve only
to make actual hostilities between the United States and Germany sooner or
later inevitable. Indeed such a situation, though unacknowledged, existed from
about September 1941, when the USS "Greer", came into conflict with a U-boat.
In October, The USS "Kearney" was torpedoed and damaged whilst on convoy duty,
and soon afterwards the USS "Reuben James", was sunk by a U-boat with the loss
of 115 lives. The actual declaration of war, in December, thus only formalised
a situation which was fast becoming reality in any case.
Operation Drum Roll
Donitz had long been eager to turn his sea wolves loose against the vulnerable
shipping lanes of the American East Coast. Hitler, fearful of bringing the USA
into the war prematurely, had resisted his U-boat supremo's pleas to initiate
action there. Instead he had ordered that a third of operational U-boats be
deployed to the Mediterranean, where they achieved relatively little of value
against the limited numbers of Allied merchant ships operating there.
At last, in January 1942, Donitz was given the long-for permission to strike at
the USA. "Operation Paukenschlag" ("Drum Roll") began in the middle of the
month, and initially involved only five U-boats, manned by veteran crews,
operating off the North American coast between the Gulf of St Lawrence and Cape
Hatteras. In the space of two weeks the five U-boats sank 20 merchant ships
totaling 150,000 tons. This was merely a foretaste of the massacre to come.
Though a hell for the crews of so many merchant ships, the eastern US seaboard
in the spring of 1942 was a paradise for U-boat men. There was as yet no convoy
system ; vessels sailed individually, making free use of their radios, fully
lit at night, against the brilliantly illuminated backdrop of coastal cities
where a blackout would not be fully in operation for another five months.
During daylight hours the U-boats remained submerged, and surfaced at nightfall
to wreak havoc with guns and torpedoes. On an average night, a U-boat might
hope to claim three victims, with resulting immense losses in supplies and
For the U-boat men, these six months in what they termed the "golden west" were
the high point of the submarine campaign. In May 1942 the number of U-boats
operating on the Eastern seaboard reached a high point of 30 vessels, for the
first time supplied by U-tankers (Type X and supply U-boats or "milch cows",
(Type XIV). Each of these could keep a flotilla of a dozen Type VII's at
sea for an additional month.
But by now the crest of success for "Operation Drumbeat" had peaked. In April
1942 the USA began to implement a convoy system for its coastal convoys, and
this fully operational by August. The great slaughter, which had cost 360
merchant ships totaling about 2,250,000 tons, for a loss of only eight U-boats,
But out in the Atlantic, the climax of the U-boat war was only just beginning.
Copyright © 2002 John Barratt.
Written by John Barratt. If you have questions or comments on this article,
please contact John Barratt at:
About the author:
John Barratt has authored many books to include: Armada 1588, The
Battle of Marston Moor, The Civil War in South-West
England 1642-1646, and Cavalier Generals.
Published online: 12/15/2002.