FREE ESSAY ON THE NORTH ATLANTIC RUN: THE SUBMARINE WAR AND THE ALLIED RESPONSE DURING WW 2

THE NORTH ATLANTIC RUN: THE SUBMARINE WAR AND THE ALLIED RESPONSE DURING WW 2

The North Atlantic Run: The Submarine war and the Allied Response 
in the Second World War 
In September 1939, with the beginning of World War II, German U-boat operations got under
way against allied forces; the allies responded to the U-boat threat with a number of
counter measures. 
The combined affect of protection of ships by convoys, harassment of U-boats by
airplanes, and other anti-submarine warfare measures, reduced the ability of the U-boats
to cut Britain off from her 
suppliers in North America. In order to assess the effectiveness of the allied response,
it is first necessary to look at the U-boats. In looking at the U-boats it is not only
necessary to look at the 
various types of U-boats and their deployment, but also to look at the German's goals and
the tactics that they employed in an attempt to reach those goals. 
The Treaty of Versailles ending world war one prohibited Germany from having any U-boats.
When the treaty was changed under The Anglo-German Naval agreement, one of the things
that the 
Germans did to rebuild their navy was to rebuild the U-boat wing. Their first U-boats
were for general sea-going and coastal abilities, the U-boats first built for this
purpose were types I and II. The type I had a surface speed of 17.75 knots and 8.25 knots
submerged on electric engines, for armament it had 4.1 inch 
and 22 mm. anti-aircraft guns and six torpedoes. In comparison, the type II had speeds of
13 knots surfaced and 7 knots submerged with three torpedoes and one 20 mm. anti-aircraft
gun. The type II was 
smaller than the type I. 
The Germans developed other U-boats between types III and VII, but the most popular model
came with the type VII. The type VII had a displacement of 500 tons and with about 700
built, became the German's main U-boat. It was equipped with a 3.5-inch anti-aircraft
gun, four bow torpedo tubes, a single stern torpedo tube, and carried 14 torpedoes; it
had a surface speed of 16 knots. The Germans also built several other U-boat types, the
most popular being the type IX with a displacement of 750 tons and 150 being constructed.
The type IX had a 4.1-inch anti-aircraft gun, 4 bow torpedo tubes, 2 stern tubes, and
carried 19 torpedoes; it had a surface speed of 17 knots. Along with these main U-boats
the Germans also had 10 supply U-boats built for refueling their other U-boats to extend
their range. The type XIV U-tanker had a displacement of 1688 tons and had no torpedo
tubes, instead the room was used to carry 635 tons of fuel, which could be used to
resupply about twelve other U-boats. All of these U-boats were, as 
with the types I and II, slower under water as they had to switch to their electric
engines, their speed was thus reduced to about 6 or 7 knots. 
These U-boats used, or tried, several different tactics against the allies during World
War II to meet their war aims, which was to attack . . . Britain's supply lines . . . for
the achievement of our naval strategic aims . . .  to cut her off from her suppliers in
North America. Militarily, the Germans tried to use the U-boats in support of other
operations. The most famous of these was the invasion of Norway in April 1940. The
Germans had planned to use the U-boats to protect their landing vessels against British
attack while troops were dropped of in Norway and the vessels returned to Germany. During
the invasion the Germans used all the U-boats that were available, assigning them
primarily defensive roles. Thirteen U- boats were used to prevent the British from
interfering in the landings in Norway and another four U-boats were then used to protect
German communications lines between Germany and Norway. 
Another thirteen were used to attack the British Home Fleet if the British decided to
send them to interfere with the invasion. The use of the U-boats in the invasion was
basically a failure because 
their torpedoes were adversely affected by the high latitude as well as the degaussing of
the British vessels. The magnetic detonators therefore would not go off. 
The primary use of the U-boat was against traffic between Britain and North America. In
these operations the Germans had two basic tactics, operations on their own, and
operations in what were 
termed Wolf Packs. The U-boats had tried Wolf Pack tactics as early as 1937 in training
exercises, but with the outbreak of the war wolf packs were deemed unfeasible due to the
inability to coordinate their actions; the U-boats were left to operate of their own,
wandering the seas looking for targets to fire upon. Thus they did not sink as many enemy
ships as would have been liked. The head of the German U-Boat, Admiral Dnitz, developed
Wolf Pack tactics. He developed this idea to counter the use of the convoy system that
used escorts to protect the ships. He thought that you had to throw everything that you
had, in a coordinated fashion, at the enemy in order to destroy him. Dnitz said in his
memoirs that, 
. . . It is essential, in an attack on any given 
objective, to be able to deliver the attack in as great 
strength as possible - in other words, by means of 
tactical co-operation and tactical leadership, to bring 
a number of U-boats to attack simultaneously the given 
objective . . . A massed target [like a convoy], should 
be engaged by massed U-boats . . . . 
It was not until 1940 that the Germans were ready to employ these tactics. The problem of
coordinating the attacks was fixed by the use of radio and aircraft patrols, to let the
U-boats know 
where a convoy was. When U-boat command would find the position of a convoy they would
radio the U-boats its location and order them to proceed towards it in a line. The first
U-boat to come in contact with the convoy would radio the others its precise location and
the other U-boats would then meet up with the first U-boat and attack. The Wolf Pack
tactics were extremely successful with 274 ships sunk in five months; one convoy in
October, SC7, lost 20 of 34 ships to the Wolf Pack tactics, a loss of 59%. 
An interesting variation of this tactic was also tired with limited success. It involved
luring an enemy ship into a line of submerged U-boats and when it came into range they
would fire upon it. An example of this was when the Bismarck and a line of U-boats near
Greenland tried to lure some enemy vessels into their path, the plan failed when the
Bismarck had to return to France. Another 
attempt was made with U-boats returning home, the King George V passed near one of them
but was left unharmed as the U-boat had no torpedoes! 
With these tactics in place, the allies met a formidable adversary. To deal with the
U-boats the allies implemented several countermeasures, the most famous and effective of
these measures was the convoy system and the use of aircraft to attack, destroy, or scare
off the U-boat. 
At the outbreak of the war, Dnitz's allied counterpart was the First Lord of the
Admiralty Winston S. Churchill, the future Prime Minister. In September of 1939,
Churchill used several measures against the U-boat threat. Firstly, he employed the
intelligence apparatus of Britain against it to analyze the U-boat threat. On September
5th, 1939, he wrote to Admiral Pound and others, 
. . . What does Intelligence say about possible 
succoring of U-boats by Irish malcontents in west of 
Ireland inlets? If they throw bombs in London, why should 
they not supply petrol to U-boats? Extreme vigilance 
should be practiced, and the closest contact maintained 
between the DNI [Director Naval Intelligence] and 'C.' 
[Intelligence Services] . . . . 
By 1941 Naval Intelligence even began to break the German codes used to encrypt
communications with their U-boats; they also used radio direction finders to pin-point
the location of the U-boats. This allowed the British to be able to divert convoys from
where they knew U-boats to be. 
Along with the increased vigilance of, and cooperation between, the intelligence services
against the U-boat threat, Churchill also recommended several other options to Neville
Chamberlain. In a meeting with the war cabinet in September 1939, he said that . . . All
possible steps were being taken to 
introduce the convoy system . . . and that aircraft should be used to protect shipping .
. . on the South-Western approaches and off the coast of Spain. Between the 8th and the
11th of September, he recommended that radar be installed on ships to help protect them
against U-boat attacks on the surface and to help telling the difference between friend
and foe. He also recommended to Chamberlain that a Ministry of Shipping be established
to, among other things, 
. . . provide and organize the very large ship-building 
program necessary as a safeguard against the heavy 
losses of tonnage we may expect from a U-boats attack 
apprehended in the summer of 1940 . . . . 
The biggest measure that the British used against the U-boat was one that they had
learned in World War I, this was the use of the convoy system. In this system ships would
all meet in a 
common port, like Halifax or New York, and wait to be grouped together for a trip across
the Atlantic ocean. The merchant ships would be grouped together in the center of the
convoy, while their 
escort ships, armed naval vessels, would surround them on the perimeter. The idea behind
the escort system was to prevent a U- boat from getting in torpedo range of the merchant
ships. The 
problem with the escort system was that even though the ships were somewhat protected
against attack, the act of getting into and out of a convoy slowed down shipping. The
ships all had to meet in a 
common port, cross the Atlantic at the same speed when some of the ships could have gone
faster, and then break out of convoy formation in a common port on the other side of the
Atlantic which 
may not be the port that they had intended to go to. This slow down caused the amount of
cargo to be ship by Britain's merchant ship to be cut by one third. Even without
attacking the convoys, the 
Germans had succeeded in at least choking Britain's supply lines some what. 
Unfortunately, the convoys were susceptible to attack by concentrations of U-boats in the
Wolf Pack tactics previously explored; the British needed other means to protect their
shipping from attack by U-boats. They found part of the solution in the use of aircraft.
The biggest enemy of the U-boat, was itself. Because it had to run on battery power when
submerged, it had to surface when those batteries died so it could go over on diesel
power and recharge them. Because it was on the surface, it was vulnerable to 
attack. It was this problem with the U-boat that the allies exploited. 
To attack U-boats on the surface, the British employed aircraft. At first the aircraft
had limited success against the U- boat due to problems in the bomb that they were using
and in finding the U-boat and closing for the final attack. The bomb that they were first
using was a 100 pound bomb. On the 5th of September 1939, an Anson of No. 233 Squadron
tried to bomb a U-boat as it was submerging. The bomb that they dropped probably would
have got the U-boat but for the fact that it skipped off the water like a rock that you
would throw across a pond. The bomb bounced off the water and exploded in the air under
the Anson. The plane was badly damaged and the crew had to put down in the ocean, luckily
their 
dinghy had not been damaged and they managed to survive. To fix the problem with the bomb
skipping off the ocean if it did not directly hit a U-boat on the surface, the British
modified a depth charge. The navy had been using a 450 pound depth charge against the
U-boats, so the British took the Mark VII naval depth charge and modified it with . . . a
rounded fairing fitted to the nose and fins at the rear to stabilize it during its
passage through the air. The weapon had two disadvantages, in order to destroy a U-boat
if it made a direct hit, the depth charge would have to roll off the U-boat and
underneath and explode. Another 
disadvantage was that the weapon had to be released lower than 100 feet in the air and
the aircraft had to be flying slower that 115 mph or the depth charge would be damage
upon impact with the water. 
The aircraft also had problems in finding its target and methods. The aircraft were later
equipped with radar, but when the aircraft got within five miles, sea clutter obscured
the target from detection. The solution to this problem was the installation of a
spotlight on the airplane, called the Leigh Light. The 
aircraft would find its target using the radar and close on it, when it got almost within
the range where it would lose the target due to sea clutter, it would illuminate it with
the Leigh Light and make its final approach and fire upon it. 
To deal with the threat from the air, the Germans began to install Schnorchels on their
U-boats. The Schnorchel was a device raised to the surface of the sea that allowed the
U-boats to vent their diesel engines thus enabling them to be used underwater,
eliminating the need to surface to recharge the batteries. By 1943 all the U-boats were
refitted with the Schnorchel and new U-boats had it incorporated in their design. 
For submerged U-boats, there were two related methods for detecting them. The first was a
crude form of sonar called ASDIC, named after the Allied Submarine Detection
Investigation Committee that developed it. The ASDIC transmitted a sound that was
reflected off any submerged object and then picked up by a directional receiver that
would display the object on a range screen and you could read the direction of the object
from a compass receiver. Once the range and direction was found, aircraft or escort
vessels could be dispatched to go after the U- boat with the depth charges. 
The second method of detection of the U-boat was the use of sonobuoys which operated in a
similar fashion to the ASDIC/Sonar, except for the transmitters would be in the water and
the plane 
above would receive the signal. An aircraft would be dispatched to an area thought to
contain the U-boat and drop one sonobuoy to get an initial reading. Four other buoys
would be dropped along with the flight path of the aircraft, which was roughly a
cloverleaf pattern. The last buoy dropped would then give the aircraft the precise
position of the U-boat and the plane would go in for the attack with depth charges. 
In a defensive approach, the allies also fortified major bases and sources of natural
resources. An example of this is from the famous attack at Bell Island, Newfoundland, in
1942. In 1940, the 
Canadian government sent two guns and two searchlights to the island which was a major
supplier of iron ore for the allies. Two 4.7 inch guns were mounted at the ferry docks
near a cliff, one of the searchlights was installed at the beach at the east end of the
island and the other at the wharf of the ferry to the mainland. Unfortunately, these
defenses were not enough and on September 5th, 1942, a German U-boat came into the harbor
firing at three ships and sinking the Saganaga and the Lord Strathcona. The U-boat was
damaged when it ran into the Lord Strathcona in the shallow waters, damaging its conning
tower, that and the fact that she was being fired upon by another ship, the Evelyn B,
forced the U-boat to 
withdraw. 
In looking at the efficiency of the allied response, it is best to look at the numbers of
U-boats destroyed and by what method. Of 1,170 U-boats that were built, and 863 as
operational U- boats, 784 of them were destroyed by the allies. Of the 784 destroyed,
34.5% were destroyed by surface vessels, 2.8% by allied submarines, 1.1% by mines laid by
ships, 40.1% by aircraft on patrol, 7.9% were bombed in ports, 2.0% were destroyed by
mines laid by aircraft, while 11.5% were lost to unknown causes. It is 
clear that the allies had the most success at destroying U-boats from the air with a
total of 50% of destroyed U-boat being lost to various methods employed by aircraft,
whereas only 38.4% were lost 
to methods employed by various naval vessels. Although no one response to the U-boat
threat caused their defeat, the combination of all the methods that the allies used to
attack the U-boats, and 
protect against attack by them, helped lead to the defeat of the U- boat wing of the Nazi
regime.
Bibliography
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