German saboteur's delay action incendiary device : United States of America

Copper tube with a base made of copper, zinc and manganese.

During the First World War German ports were blockaded by the British, leading to a decline in quality and quantity of German clothing, equipment and food as the war progressed.

Conversley, the Germans disrupted the supply of items to Britain through sinking ships bound for their ports. One way they did this was by planting delay action incindiary devices on the vessels while the ships were being loaded.

Using delay action incendiary devices (also known as delay action ignition devices), German sympathisers were able to 'remotely' attack vessels after they left port. While most of this activity took place in 1915 and 1916 in American ports, near the end of 1918 a ship carrying food from the United States of America was unloaded in a British port. Hidden within its cargo was found one of these devices that had failed.

The device was sent to the Australian Imperial Force (AIF) Research Section of the British Munitions Inventions Department for investigation. The Section was created in November 1916 and was based at Esher in Surrey. It worked on a variety of inventions for the war effort, but also on occasion investigated enemy inventions and munitions.

The investigators determined the item was of American manufacture, made by German sympathisers. It contained an acid that within about 3 days corroded a wire, which released a spring that should have started a fire and sink the vessel, or at the very least destroy much of the cargo. However, the copper tubing had fused when the fire began, causing failure in the device and so the fire did not spread.