10 Surprising Facts About the Father of Submarine Warfare

From 1775 to 1783, the Revolutionary War pitted an underdog army against a global power. The Americans had fewer weapons and fewer men, but they beat the odds by welcoming new tactics and weapons. They even took seriously the work of a shy farmboy-turned-inventor by the name of David Bushnell.

After spending his spare time reading, he went to study at Yale. There, he worked on projects that he realized could aid the war effort. The American generals called his work “an effort of genius.” He is now known as the father of submarine warfare. Here are ten fascinating facts about Bushnell—a genius who showed the American spirit before the United States formally existed—and his inventions.

Related: 10 Often Forgotten Battles That Helped Shape the Modern World

10 His Student Work Was Scary

When most students have a project to do at university, it often involves late nights in the library and lots of writing. And most will not choose a project widely considered impossible—one that scares their fellow students. David Bushnell did both.

At Yale, he studied topics he thought would help him as an inventor. These included religion, geometry, natural philosophy, and mathematics, which he was said to have excelled in. However, his most significant academic achievements were his experiments with gunpowder.

Although it was thought impossible, Bushnell believed he could make gunpowder explode underwater using ideas he had read about in European textbooks. His experiments were said to have terrified onlookers, but Bushnell succeeded—first with two ounces and later with two pounds of gunpowder. He became the first person to set it off underwater and was also the first to detonate it using a timer.^[1]

9 He Caused One of the Revolutionary War’s Strangest Battles

After he showed that gunpowder could go off in water, Bushnell started testing different water-based ways to deliver explosives to their target. Later in the Revolutionary War, one of these played a role in a bizarre battle that became the subject of a song popular with George Washington’s soldiers—”The Battle of the Kegs.”

Although the name of the song sounds harmless, these kegs were dangerous weapons; the British called them “infernals.” Bushnell had made the bombs out of kegs because they could float down rivers toward British ships. They were spring-loaded and would explode on impact.

The kegs were launched in the Delaware River at the end of 1777, and by early January 1778 they were approaching British ships in Philadelphia. But since the river was frozen, the kegs struck a couple of small boats instead, alerting the British, who opened fire on all the bombs. The British then celebrated their victory over their inanimate enemies—much to the amusement of Francis Hopkinson, who composed the sarcastic song to mock them.^[2]

8 He Invented Sea Mines

Before he invented his infernals—essentially early torpedoes—Bushnell’s idea was to make mines that had to be manually attached to the hulls of ships. He had already exceeded the 2 pounds (0.9 kg) of gunpowder he exploded underwater at Yale; by the time he joined the Revolutionary War, his mines were around 2.5 feet (76 cm) long and held up to 150 pounds (68 kg) of powder.

They also needed a delay before detonation so the person placing them could escape. Bushnell rose to the challenge with the help of two clockmakers. They created a clockwork timing device that triggered a flintlock—the same mechanism used to fire muskets at the time. The flint and steel inside produced the spark needed to ignite the charge. The mine could be screwed into the side of an enemy ship, and the operator simply started the timer and swam to safety.^[3]

7 He Invented the First Combat Submarine, the “Turtle”

David Bushnell is best known for inventing the first submarine ever used in combat, earning him the reputation as the father of submarine warfare. His sub was called Turtle because it looked like two turtle shells facing each other, but it was an extremely impressive example of early technology.

Built from oak and held together by iron, it could submerge and rise, move forward and backward, and support an operator underwater for a short time. It had a chamber that could be flooded or emptied to adjust depth, and Bushnell turned to his clockmaking friends for the mechanical parts.

Internal and external ballast kept the sub upright during operation. A hand-cranked propeller in front provided forward motion, and another propeller on top helped with vertical movement. Bushnell is thought to have begun work on the submarine with his brother in 1775, testing it every step of the way until its first combat deployment in September 1776.^[4]

6 But It Was Not the First Submarine

Bushnell’s submarine was the first to be used in combat, but it wasn’t the first ever built. That title goes to Dutch inventor Cornelius Drebbel, who also worked on floating bombs. Both Drebbel and Bushnell used water for submersion.

Drebbel’s designs used pigskin bladders under the seats, which could be filled or emptied by loosening a rope or squeezing them. His final version could hold a crew of 16. But while Drebbel relied on oars for movement, Bushnell pioneered the use of propellers—an innovation still used in submarines today. It’s Bushnell’s mechanical solutions, not Drebbel’s manual ones that had the more lasting legacy.^[5]

5 He Caught the Attention of the Founding Fathers

Bushnell’s creativity did not go unnoticed by the Founding Fathers. They learned about him partly through the ingenuity of his inventions and partly through Yale connections. In 1775, shortly before graduating, he built the Turtle with his brother and tested it with fellow Yale graduate Benjamin Gale. Gale was so impressed he invited Benjamin Franklin to see it on his way to George Washington’s camp.

Franklin did, and soon after, Bushnell received funding from the governor of Connecticut and was visited by George Washington in 1776. Washington gave the go-ahead to deploy the Turtle, and after the war, it was Thomas Jefferson who publicly shared Bushnell’s accomplishments during a lecture to the American Philosophical Society in 1798.^[6]

4 He Never Piloted the Turtle in Combat

The Turtle’s first mission was a bold one—try to sink the HMS Eagle, the flagship of British Admiral Howe. But Bushnell didn’t pilot his own creation. None of the designs could be operated without exceeding his own physical limitations, so he trained his brother Ezra instead.

However, Ezra came down with a fever just before the mission, and Bushnell quickly trained a volunteer, Ezra Lee, to take his place. Lee had only basic instruction and struggled during the mission. After spending two and a half hours just getting to the ship against the tide, he was too tired to attach the mine. When the British noticed him, they sent a ship in pursuit. Lee released the mine, which exploded and frightened them off—allowing him to escape.^[7]

3 His Submarine Design Principles Are Still Used Today

Ezra Lee and another operator, Phineas Pratt, each made another attempt to attack British ships with the Turtle. Both failed, not because of the design, but because the British were now on high alert. A few days later, the Turtle was lost when the boat carrying it was sunk.

Still, Bushnell’s legacy endured—not only because he was the first to weaponize submarines but also because he introduced design principles that are still used today. His use of screw propellers rather than oars, and his flood valve ballast system, both directly influenced the development of modern submarines. The latter even resembles the Kingston valves still in use.^[8]

2 He Saw Action in the Revolutionary War

Bushnell’s main contributions to the war were his inventions, but he also saw action. Captured in May 1779, he was released in a prisoner swap—apparently because the British didn’t know who he was. Afterward, he joined the Continental Army’s Corps of Sappers and Miners.

These engineers primarily built roads and batteries but occasionally fought. In one instance, they fired on Benedict Arnold as he fled West Point to the HMS Vulture. Bushnell’s unit also reencountered Arnold in 1781 during Lafayette’s efforts to capture him and helped Alexander Hamilton take Redoubt 10 at Yorktown.^[9]

1 People Still Make Replicas of His Most Famous Invention

They say imitation is the sincerest form of flattery. If true, David Bushnell has been flattered centuries after his death—not just by modern submarines inspired by his ideas, but by literal replicas.

In 2007, artist Duke Riley and two friends—including one coincidentally named Bushnell—were arrested for trying to sail their wooden sub near the Queen Mary 2 in New York. In 2003, a team from the Massachusetts College of Art and the Timber Framers Guild built a historically accurate replica. Tests showed it was seaworthy and could have succeeded in its original mission, confirming that David Bushnell was a man ahead of his time.^[10]