05 November 2015 by Dianne Rutherford

An army marches on its stomach, or so the saying goes. Certainly the supply of food, equipment and weapons was such an important aspect of the First World War that it was targeted by both sides. German ports were blockaded throughout much of the war, leading to a decline in quality and quantity of German clothing, equipment and food as the war progressed. The Germans disrupted the supply of items to Britain through sinking ships bound for their ports. One of the more interesting ways they did this was by sabotaging 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. 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.

Fortunately for the crew the device had failed and the ship made it safely to Britain. It is also fortunate for us, almost 100 years later, as it means we have the opportunity to see one of these devices first hand.

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 would start 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.

There were many reports throughout the war of objects like these, sometimes dubbed “infernal machines”. The best known version was the so called “pencil bomb” designed by Doctor Walter T Scheele, a former German military officer. Dr Scheele was the president of the New Jersey Agricultural Chemical Company and he arranged the making of hundreds of these devices in America. He was later indicted for assisting the Germans and fled to Cuba.

His device, which was manufactured as early as 1915 (well before the Americans were actively involved in the war) was a cigar shaped lead tube with a metal divider (either copper, or zinc-tin) separating two chemicals, either sulfuric acid and picric acid, or sulfuric acid and potassium carbonate. The chemicals would gradually corrode through the divider and mix, creating combustion. The thickness of the divider influenced the length of time before combustion occurred so it could take days after the ship’s departure before its cargo caught fire or exploded.

The device held by the Memorial is similar in some ways to Dr Scheele’s invention but relies upon a spring release to create the fire rather than the mixing of two chemicals to create the combustion. Regardless of technique, this aspect of economic warfare is an interesting one and is a small part of the larger story of German agents and sympathisers in America during the First World War. We are very fortunate to have the item in our collection.