Exploding Coal: An Invention by American Civil War Spies

There have always been underhand tactics in the arena of war. During the American Civil War, there was the invention of coal torpedoes, which were exploding pieces of fake coal. These were invented by a Dublin born man, Thomas Edgeworth Courtenay. His invention went on to have a revival during the Second World War. How and why exactly did this form of ‘coal’ happen to be originally invented in 1863?

The place to start is with the background to Thomas Courtenay. Whilst being born in Dublin in 1822, he moved to America to seek a better life, arriving in 1842. His career started in marine and fire insurance, with a particular focus on the steamboats sailing the Mississippi River. When Civil War loomed, he sided with the Confederacy. He entered into the secret services as a volunteer and found a way to bring his existing knowledge on steamboats to this role. He first suggested his idea for a bomb disguised as a piece of fake coal in 1863. They would be perfect for hiding in coal stores, as well as destroying steamboats and steam engines used for the Union war effort.

Thomas Courtenay in the uniform of a Confederate Army Captain, family photo, Wikimedia Commons

The devices went into production at Richmond, Virginia, in early 1864. Each device was a piece of iron with a hole in to place around 3 or 4 ounces of gunpowder, was around 4 inches across and weighed 3 or 4 pounds. Courtney was allowed 25 volunteers to make and distribute these devices, which would then only be allowed to destroy Union property. Courtenay himself was never officially paid for this work, instead he received a reimbursement of up to 50 percent of the value of the property that was destroyed.

Newspaper reports started to mention these new devices and called them either the ‘infernal machine’ or the ‘coal torpedo’.  For that reason, they became known as coal torpedoes. The term ‘torpedo’ during this period was used to describe many different explosive devices, not necessarily the marine ones we understand today.

It is now not possible to discuss how successful these coal torpedoes were as any Confederate documentation related to this was destroyed. These devices were also explicitly designed to leave as little trace behind as possible. However, there are some examples of ships that were targeted, supposedly by these coal torpedoes. These included the USS Chenago, a paddle steamer called Greyhound and a riverboat called SS Sultana.

Photograph of Bermuda Hundred, Virginia, General Benjamin Butler’s headquarters (1864), Library of Congress

The Greyhound was the floating command post of the Union General, Benjamin Butler. On the 27^th November 1864, it was sailing the James River in Virginia close to the Bermuda Hundred. On board were several Union troops and officers. Rear Admiral David Dixon Porter was one of them. He was extremely nervous about sailing through enemy territory, especially on an unarmed vessel. Porter’s concerns were proved to be entirely accurate. There was a large explosion in the engine room, blamed on ‘suspicious’ men who had brought coal on board the steamer. Luckily, the engineer closed the throttle valve, stopped the ship and opened the safety valve, meaning that the explosion didn’t cause as much damage as it could have done. No men were killed in the incident, despite some landing in the water, or jumping overboard, because of the explosion. Sadly Butler’s horses did die in the subsequent sinking, after all the men were transferred to other ships.

On 27^th April 1865, the SS Sultana was also targeted and suffered a much larger boiler explosion than was seen on the Greyhound. The Sultana was a steamer returning released Union prisoners to their freedom and around 1,700 people were killed in this explosion. In the aftermath, a Confederate agent, Robert Loudon, took responsibility for this, saying he had used the coal torpedoes. This was widely disputed, even at the time, so again, there is no definitive answer on whether sabotage really was used, even in this instance.

The ill-fated Sultana the day before her boilers exploded and she sank (1865). Library of National Congress, via Wikimedia Commons

Probably the most audacious plan involving the coal torpedoes was in December 1864. A group of Confederate agents secreted themselves over the Canadian border, armed with the devices. Their aim was to use them to destroy the U.S. Arsenal at Springfield, Massachusetts. They had managed to successfully infiltrate the site and hid a coal torpedo, including a timer, under the main staircase. Unfortunately for the agents, a watchman discovered it before it was ignited.

Photograph of The Arsenal, U.S. Armory, Springfield, Massachusetts (c.1910-1920), Library of Congress

Towards the end of the Civil War, the use of these devices seems to have slowed down. This is probably because Thomas Courtenay escaped to England to avoid charges of war crimes. He didn’t remain idle in his exile though. He still kept abreast of his American based activities via partners still in America. Courteney was incredibly confident in his product and tried to sell his exploding coal to various European governments, with no success. When he was allowed to return to America after the war, he still tried to make a living from these devices, but technology had already developed past these fairly rudimentary devices, meaning Courtenay died from poor health, and in poverty, in 1875.

Despite it being an unsuccessful venture, ultimately, for the inventor of the coal torpedoes, they had the capability of being a dangerous weapon at the time of its original incarnation. The fact that the concept was revived in the Second World War also shows its possible effectiveness. However, at the end of the American Civil War, there were others with similar or better expertise than Courtenay, including those with better technology. In 1866, Britain fired the first automatic torpedo from a moving ship, proving just how much in a short space of time technology had moved on, making the coal torpedoes pretty much obsolete, even if a fascinating and quirky device.

Spencer C. Tucker (ed), American Civil War: The Definitive Encyclopaedia and Document Collection (Bloomsbury, 2013), p. 447

Chris McNab, ‘Born Out of Desperation? The Coal Torpedo’, HistoryNet,  https://historynet.com/born-out-of-desperation-the-coal-torpedo/

Spencer C. Tucker (ed), American Civil War

Chris McNab, ‘Born Out of Desperation? The Coal Torpedo’

John Grady, ‘Mine Warfare in the Civil War’, The Army Historical Foundation, https://armyhistory.org/mine-warfare-in-the-civil-war/

Ibid

Ibid

Spencer C. Tucker (ed), American Civil War, p. 391

Ibid

Ibid

Ibid, p. 448

Chris McNab, ‘Born Out of Desperation? The Coal Torpedo’