In the Cross­hairs:
Allied Shipping

image icon - click to for more details about the image U.S. Army soldiers guarding Boston piers; Chemist in a lab; Bomb maker Dr. Walter Scheele; The USS Huron

plots were
percolating in the United States in 1915. As opposing forces on the European continent remained mostly deadlocked and settled into prolonged trench warfare on the Western Front, the Germans ramped up their efforts to deny their battlefield adversaries with needed munitions from America. They zeroed in on Allied shipping in the Atlantic, determined to disrupt the vital lifeline between America and the Allied Powers on both the Western and Eastern Fronts.

It was a daunting task, requiring Germany’s New York-based spymaster Franz von Rintelen to employ the services of Walter Scheele, a skilled chemist who moved to the United States from Germany in 1890 and became a sleeper agent awaiting orders. He wouldn’t have to wait very long. In 1893, Scheele began working as an industrial spy for the German Army Attaché in Washington and, at the start of World War I, he was the only German agent in the United States. With approval and financing from von Rintelen, Scheele developed a novel, game-changing invention known as a Cigar Bomb for its unique cylindrical shape. The bomb was a simple time-delay incendiary device, comprised of a lead pipe filled with two forms of acid. When mixed, the chemicals produced an intense flame, melting the pipe and destroying the evidence.

image icon - click to for more details about the image Cigar Bomb sketch; Dr. Scheele’s incendiary device patent; German bomb maker Captain Charles von Kleist
artifact icon - click to for more details about the image Uncle Sam takes aim at German rats

To avoid detection, the casings of the Cigar Bombs were manufactured aboard the SS Friedrich der Grosse, an interned German ship held in New York Harbor. Dr. Scheele and his assistant, Charles von Kleist, then added the acids to the devices at a laboratory in Hoboken, New Jersey. Planted aboard merchant ships crossing the Atlantic – many by Irish stevedores who loathed the British Empire – Scheele’s inventions proved highly effective.

artifact icon - click to for more details about the image Uncle Sam takes aim at German rats

In May 1915, the SS Phoebus – a British merchant ship carrying artillery shells from New York to Russia – was the first sabotage target to catch fire at sea, its cargo destroyed as a result. Over the succeeding months, von Rintelen expanded his operations to other East Coast ports, and dozens more munitions and cargo ships leaving the United States for Europe fell victim to Scheele’s ingenious incendiary device. It became one of the most effective and innovative weapons of World War I. German saboteurs destroyed explosives and munitions in more than an estimated thirty-five ships, with an approximate value in the tens of millions of dollars. If the fire from the incendiary devices didn’t destroy the munitions, water from the ship’s firehoses would finish the job by neutralizing the explosive material.

Aware that he was under observation by U.S. law enforcement, Scheele fled the United States in 1916. But law enforcement had the goods on him, and he was tried and convicted in absentia. Scheele was ultimately found in Cuba in 1918 by U.S. authorities and extradited back to the United States. Facing prison, Scheele began cooperating with U.S. military officials and scientists on weapon designs; his famous Cigar Bomb design was later patented by the U.S. Navy. He died of pneumonia in 1922.