Anti U-Boat Measures

What were anti U-boat measures?

Britain was in danger of losing the war because the shipping which the country relied on was being sunk by German submarines, or U-boats. Countering the U-boat threat was seen as a very important task.

What anti U-boat measures did the British use in the First World War?

There were 4 main anti U-boat measures brought in by the British to try and avoid the damage being done by German U-boats;

• ❖ Minefields were laid across the English Channel and in the North Sea. If a U-boat collided with a mine it would be destroyed.
• ❖ Depth charges were introduced. These were explosives which were dropped by the British and exploded at certain depths.
• ❖ A convoy system was introduced. This meant merchant ships carrying supplies sailed in groups protected by the Royal Navy.
• ❖ Q-ships were introduced. These were warships which looked like merchant ships but they were actually armed and could fight the U-boats.

How successful were British anti U-boat measures?

The anti-U-boat measures were extremely successful for a number of reasons:

• ❖ Mines were highly effective. In 1917 alone, 20 out of 63 U-boats were sunk after they collided with mines.
• ❖ As crews became more experienced with using depth charges, they became more effective. In 1915 only five U-boats were sunk in this way, but the number reached 22 by 1917.
• ❖ Convoys were extremely successful, with only 1% of ships in convoy being destroyed.
• ❖ Q-ships attacks accounted for 10% of all U-boats sunk.