A bar chart showing the average number of U-boats – both German and Italian – operating in the Atlantic and the number sunk or probably sunk between September 1939 and April 1945.
Background to this source
This is one page of a file of charts kept with Churchill’s official Prime Ministerial papers.
The war with Japan in the Far East is still ongoing. Officials prepared these graphs summarising U-boat activity in the Atlantic.
How can we use this source in the investigation?
Remember, we’re hoping that this source can be useful to us in investigating why Winston Churchill was so worried about the Battle of the Atlantic. Sources usually help historians in two ways:
Surface level
According to the chart, when were there most U-boats in the Atlantic?
When were there fewest U-boats in the Atlantic?
When did Italian U-boats cease to play a part in the Battle of the Atlantic?
When were most U-boats sunk?
When were fewest U-boats sunk?
From this graph, when would you say that the Battle was won?
Deeper level
Which of the inferences below can be made from this source?
On a scale of 1-5 how far do you agree that this source supports this inference?
Which extract(s) from the source support your argument?
The Royal Navy was very good at sinking U-boats.
The Royal Navy got better at sinking U-boats as the battle progressed.
Germany had enough U-boats to win the Battle of the Atlantic.
Germany never had enough U-boats to win the Battle of the Atlantic.
Figures from wartime are notoriously tricky sources for historians. It’is very difficult to get accurate figures. These probably represent what the British government believed to be accurate.
Since they’re not for publication and the war is over, these figures aren’t being used for propaganda. However, this doesn’t necessarily mean they’re exact!
On the other hand it’s probably fair to say that they’re useful in indicating overall trends rather than exact numbers.