The Battle of
the Atlantic
The other attack on the
United States
The Battle of the Atlantic
 Fully
equipped to go to war with the Axis,
the U.S. will soon realize that the war has
come to their shores
 We
will find ourselves in a battle for the
seas before we even get to Europe
 “Britain’s
lifeline can’t be severed.”
The Battle of the Atlantic
 Before
the U.S. joined the war, Germany
had used U-Boats (German Submarines)
effectively on allied ships, especially the
British Navy
 Now
in early 1942 with the U.S. in the war,
an all out attack is ordered by Germany
 “Operation
Drumbeat”: German attack
on the ports of the East Coast of the U.S.
The Battle of the Atlantic
 Why
did Germany bring the war to us?
 U.S.
ships, loaded with supplies waited in
port for the voyage across the Atlantic
 Silhouetted
against the bright lights of
American towns and cities, these ships
were easy targets for U-Boats
The Battle of the Atlantic
 The
U.S. would eventually lose over 3.1
million tons of supplies because of U-Boats
in just 1942
 The
U.S. had no initial defense, but
eventually fought back, sinking 2 U-Boats
 Wrecks
today can be found off the coast
of Rhode Island and New Jersey
The Battle of the Atlantic
 We
had very few anti-submarine ships in
1942 so little was done initially
 How
does the U.S. defend itself?
 Blackouts:
Citizens living on the coast
were ordered to turn off lights at night so
our ships could not be seen
The Battle of the Atlantic
The Battle of the Atlantic
 Blackouts
worked initially, but the U.S.
cannot hide from Germany behind the
cover of darkness. We must get to Europe
 The
first merchant ships that attempted to
cross the ocean were unsuccessful
because they carried no defenses and
sonar was new
The Battle of the Atlantic
Admiral Karl Donitz:
Commander of the
German U-Boat
fleet
The Battle of the Atlantic
Admiral Ernest King:
Commander-in-Chief
of the U.S. Naval
Fleet
The Battle of the Atlantic
 Admiral
King needed a new strategy but
was limited because of the Destroyers for
Bases Deal
 Finally
by July 1942 King has enough
destroyers to form a convoy
 Convoy:
A group of ships that would sail
together to provide protection against UBoats
The Battle of the Atlantic
The Battle of the Atlantic
 Convoys
were successful at first, but
Admiral Donitz would also adapt his
strategy
 Donitz
orders his U-Boats to attack in
groups known as Wolfpacks
 U-Boats
would patrol in straight lines, but
converge when a convoy was spotted
The Battle of the Atlantic
The Battle of the Atlantic
 The
Wolfpacks had their disadvantages
and the convoy system was proving to be
successful
 The
U.S. also develops new defenses such
as depth charges, advancement in sonar
and airplanes, and the HF/DF system
The Battle of the Atlantic
 The
biggest break for the Allies came in
late 1942 when they broke the secret
German code
 Germany
had used an Enigma Machine
to transmit messages between U-Boats
A
U-Boat was captured and boarded,
and code books and enigma keys were
recovered
The Battle of the Atlantic
 Using
these books and keys, the British
were able to break the German code
with their system known as Ultra
 This
allowed the Allies to locate German
Wolfpacks and route their ships away
from them and safely to England
The Battle of the Atlantic
 The
Battle of the Atlantic was one of the
most costly
 Thanks
to technology, code breaking,
strategy, and the effort of military leaders,
the U.S. reaches Europe and Africa, and
can start the war