Tinkerer, Sailor, Soldier, Surgeon

A Connecticut Yankee

So many of our first patriots were accomplished men of letters, lawyers, judges, planters, merchants but relatively few were men of science and technology.  David Bushnell falls into the latter category.
Bushnell was born in Saybrook, Connecticut on 30 August 1742, the son of a farmer. He was the first of five children and grew up and worked the family farm near Westbrook. Following 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 used this knowledge not only in the construction of the underwater mine but 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 manned by a single operator who powered it by two hand-cranked screw propellers. A system of water pumps took in and expelled water to control the climb or descent of the craft, which could reach a depth of about 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 phosphorous. 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 made an attack on the British fleet anchored in New York harbor under the command of Admiral Richard Howe. Unfortunately, Bushnell became ill and a Sergeant named Erza Lee volunteered in his place. On the night of 6 September, a pair of whaleboats towed the Turtle offshore where it began its attack. Pumping feverishly, Lee slowly guided the Turtle towards the British fleet. Despite unfair tides, Lee managed to pull up to the mother of all targets, Lord Howe’s own flagship, the 64-gun ship of the line, HMS Eagle. The Turtle’s drill failed to penetrate the hull because it was blocked by an iron bar. With air dwindling, Lee abandoned the efforts and released the mine, which floated free.  The mine finally erupted with a tremendous explosion that shot a plume of water into the night air.  The unexpected iron bar prevented what could have been a catastrophic kill on a major target, possibly changing British naval tactics for the duration 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 13 August 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 up with a small schooner. It detonated the explosion 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 loaded with explosives off Bordentown, New Jersey. The kegs were intended 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 up the floating kegs as well as pretty much anything else that floated.. This event was satirized in the poem, “Battle of Kegs,” by Francis Hopkinson. Rebel propaganda painted this as an embarrassment for the hapless Royal Navy. But Bushnell's life 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 once detained him but he managed to get released.  Later that year Bushnell left the world of maritime warfare and joined the Continental Army when General George Washington named him commander of the first company of sappers and miners at West Point, NY. Captain Bushnell served with competence, for the remainder of the conflict and led the sappers in the siege of Yorktown, the battle that effectively ended the war. After his discharge from the Continental Army, he returned briefly to Connecticut and later spent a brief period in France but returned 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 seminal in the later proliferation of underwater mines, torpedoes, and of course, the submarine. His basic use of water for ballast continues to this day, as does the use of the propeller. Although his impact on the course of the American War for Independence was marginal, he did have an impact on the long term trajectory of naval warfare. No small feat for a Connecticut Yankee farm boy.

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