Blockades and U-boats
Blockading Britain
• The Germans knew
that they would be
hard pressed to
defeat the British
navy.
• They did, however,
believe that they
could cause huge
problems for Britain
by stopping supplies.
Unrestricted Submarine Warfare
• The Germans
declared a war zone
around Britain into
which they sent their
U-boats or
submarines.
• They declared that
they would sink any
supply ship in this
area.
Countering the U-boats.
• Floodlights and mines
were put on the Dover
channel to stop U-boats
using it.
• The British introduced a
“Convoy system” to
protect supply ships
coming to the country.
• In 1917, Britain was in
trouble, running out of
food supplies, but by
1918, the convoy system
began to work.
3.5
3
2.5
tonnage
of British
shipping
lost
(millions
)
2
1.5
1
0.5
0
1915
1917
Angering America
• This policy of the
Germans meant damage
and casualties to other
countries not involved in
the war – particularly
America.
• Famously, a British ship,
the Lusitania, was sunk
with 128 American
passengers on board.
This was one reason
America joined the war.
The British response
• Britain also saw the value
of blockading supply
ships from Germany.
• They forced any ship
heading for Germany to
be stopped and searched
with key supplies being
removed.
• This was a key factor in
Germany’s defeat.
True or False
Blockades and U-boats
1) The Germans used U-boats or submarines to blockade
the British coast and stop supplies reaching the U.K.
2) Canada suffered 128 deaths when the Lusitania was
sunk by a German U-boat in 1915.
3) Britain came up with certain means of stopping U-boats
including the Convoy System where supply boats had
protection.
4) The Convoy system did not work and more goods were
lost in 1918 than 1917.
5) The British also stopped supply ships heading for
Germany and removed any confiscated goods.
6) Although the U.S.A didn’t like this, they preferred it to the
U-boat attacks preferred by the Germans.