U-boat campaigns 1917/18

Threat in 1914

Had 24 total but 10 in North Sea

Limited attacks on merchants

Threat in 1915

Decision mad to starve Britain deemed impossible

Prize rules abandoned due to Q-ships

British waters declared ‘free game’

Ended due to fears of bring neutrals into war

U-boats from 1914

Initially crews of 35 but as grew so did crews to 50

Armed with torpedoes and a gun

Hard to see and locate but mostly travelled on surface

Prize rules meant that merchant ships should be allowed to leave before sinking

Unrestricted warfare 1917/18

Holtzendorff decided they needed to sink 600k for 1st month and 500k for next 6 to starve GB - This was largely miscalculated and tonnage does not accurately show damage

Attacks remained centred around British coast

Grew from 105 → 129 U-boats from Feb - Jun, more meant more time in repairs

Material impact of unrestricted submarine warfare

500 skips sunk form Feb-Mar

395 sunk in April

6.2 m tonnes sunk by end of year

Political impact of unrestricted submarine warfare

Neutral nations began warrying about exporting to GB

April 1917 US joins war

GB gov in panic due to failures in France and shipping losses

Shipping losses censored to retain morale