Tinkerer, Sailor, Soldier, Surgeon

A Connecticut Yankee

So many of our first patriots were accomplished men of letters—lawyers, judges, planters, and merchants—but relatively few were men of science and technology. David Bushnell falls into the latter category. Bushnell was born in Saybrook, Connecticut, on August 30, 1742, the son of a farmer. He was the first of five children and grew up working on the family farm near Westbrook. After the death of his father in 1769, he sold his half interest in the farm to his brother Ezra and entered Yale College in 1771.

David Bushnell

Bombs to Boats

While at Yale, he became fascinated by the possibility of underwater explosions. An inventive tinkerer by nature, Bushnell successfully combined a black powder charge with a clockwork timing device, thereby creating the first naval mine. He applied this knowledge not only to the construction of the underwater mine but also later in creating floating torpedoes that exploded on contact. He collaborated with the wealthy New Haven inventor and manufacturer Isaac Doolittle to develop the first mechanically triggered time bomb as well as the first screw propeller. As he set about conceiving a practical delivery system for this unique weapon, the onset of the American War for Independence created a new sense of urgency to his efforts.  By the fall of that year, he had designed and engineered the American Turtle (better known as Turtle), a primitive submarine. He named it Turtle because it looked like two turtle shells lashed together. Not a thing of beauty, but it worked.

Turtle Design Sketch

Test and Evaluation

Gen Israel Putnam

This primitive submarine was operated by a single operator, who powered it using two hand-cranked screw propellers. A system of water pumps took in and expelled water to control the craft's climb or descent, which could reach a depth of approximately 15 feet. To see, the pilot had a small conning tower with several windows. The tower contained a depth gauge and a compass lit by phosphorus. The Turtle’s punch was Bushnell’s original clock/mine combination connected to a metal drill engineered to bore through the copper sheathing coating the hulls of British warships.  Once the mine was attached and released, the timing mechanism engaged, leaving the Turtle one hour to escape before a 150-pound charge exploded, detonated by a flintlock trigger device. Bushnell arranged a successful demonstration, essentially a “demval” in today’s acquisition parlance. On hand for the event on the Thames River was Connecticut General Israel Putnam, who urged the American government to continue funding for its “full operational capability.”

Turtle Replica

Run Silent, Run Deep - Sorta

History was made in the summer of 1776 when the Turtle attacked the British fleet anchored in New York harbor under the command of Admiral Richard Howe. Unfortunately, Bushnell fell ill and a sergeant named Ezra Lee volunteered in his place. On the night of September 6, a pair of whaleboats towed the Turtle offshore, where it began its assault. Pumping feverishly, Lee slowly guided the Turtle toward the British fleet. Despite challenging tides, Lee managed to approach the primary target, Lord Howe’s flagship, the 64-gun ship of the line, HMS Eagle. The Turtle’s drill failed to penetrate the hull because it was obstructed by an iron bar. With air running low, Lee abandoned the effort and released the mine, which floated free. The mine ultimately erupted in a tremendous explosion that shot a plume of water into the night air. The unexpected iron bar prevented what could have been a catastrophic blow to a major target, potentially altering British naval tactics for the remainder of the war. See my Yankee Doodle Spies post on "The Boat" for a more detailed discussion of this attack.

Bushnell's Turtle takes on HMS Eagle
and initiates submarine warfare

Torpedoes are Running

Bushnell was undaunted. Confident in his development, he continued improving the Turtle. He launched several small attacks against individual British ships, but inexperienced pilots and unfavorable tides thwarted each effort. The Turtle was lost the following October when a transport carrying it was sunk by British cannon fire on the North (Hudson) River. Undaunted by all the failure, Bushnell continued tinkering with naval mines and explosives. On August 13, 1777, he released another mine that floated toward the HMS Cerebus, anchored in Black Point Bay. This time, the tides were favorable, but the device got snagged on a small schooner. It detonated, killing three British sailors.

 Turtle needed to be towed  into attack position by rowboats

Battle of the Kegs

A Bushnell mine exploding
unnerved the British

He tried again in January 1778, this time releasing 20 large kegs filled with explosives off Bordentown, New Jersey. The kegs were meant to float down the Delaware River and destroy the British fleet at Philadelphia. One mine exploded near a British rowboat, killing several sailors. The attack so unnerved the British fleet that it spent the rest of the day shooting at the floating kegs as well as nearly anything else that floated. This event was satirized in the poem, “Battle of Kegs,” by Francis Hopkinson. Rebel propaganda depicted this as an embarrassment for the hapless Royal Navy. However, Bushnell's career as an undersea weapons developer was over.

Captain David Bushnell's sappers and miners
fought during the siege at Yorktown

The Sapper

Bushnell returned to Saybrook in the spring of 1778. Local Loyalists had once detained him, but he managed to secure his release. Later that year, Bushnell left the world of maritime warfare and joined the Continental Army after General George Washington appointed him commander of the first company of sappers and miners at West Point, NY. Captain Bushnell served competently for the remainder of the conflict and led the sappers during the siege of Yorktown, the battle that effectively ended the war. After his discharge from the Continental Army, he briefly returned to Connecticut and later spent some time in France before coming back to the United States to settle in Warrenton, Georgia, where he practiced medicine. He died there in 1824.

David Bushnell Memorial in Georgia

Seminal Submariner

In the long run, David Bushnell’s efforts were foundational for the later spread of underwater mines, torpedoes, and, of course, the submarine. His basic use of water for ballast continues even today, as does the utilization of the propeller. While his impact on the course of the American War for Independence was limited, he nonetheless influenced the long-term trajectory of naval warfare. No small achievement for a Connecticut Yankee farm boy.

Today's submarines are descendants of Bushnell's
Turtle and still share its basic design, albeit on steroids