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Revolution in a Half Shell

By (July 1, 2010) No Comment

Turtle: David Bushnell’s Revolutionary Vessel

By Roy R. Manstan and Frederic J. Frese
Westholme Press, 2010

On the night of September 6, 1776, the HMS Eagle sat docked in New York Harbor, one of the many ships his majesty’s government had sent to help squash the colonial rebellion that had broken out a little under a year before. As the crew of the ship gathered below and a few soldiers paced the deck looking out onto the lush, green island of Manhattan, a small. strange vessel made its silent approach. As the sun rose, a huge explosion near the Eagle sent water gushing into the air, and an alarm sounded throughout the harbor. The mine had missed its target (the hull of the ship), but history saw the beginning of a new age of weaponry. The stealthy little vessel would be called the Turtle, and it would be the herald of submarine warfare.

Just in time for the 4th of July, Roy Manstan and Frederick J Frese have brought us a new history of a forgotten chapter in the American Revolution. Turtle: David Bushnell’s Revolutionary Vessel tells the story of Connecticut inventor who is considered by many to be one of the founding fathers of the submarine:

David Bushnell was reserved but strong willed. Secure in the quality and efficacy of his designs, he was able to convince a small group of individuals to support his vision. Persistence, confidence, and sheer willpower led to the creation of a submarine with the capability to undertake a combat mission.

But this is more than just a history of an 18th-century invention; both the authors have been involved in creating their own Turtles and have tested their subs in the Connecticut River. Manstan helped in the construction and sailing of a replica in 1976 during the bicentennial celebrations, and, along with Frese, a high school teacher in Old Saybrook, CT (Bushnell’s hometown), oversaw a student-lead construction of their own submarine as part of an afterschool project. So the authors’ expertise extends well beyond the library, and The Turtle is the better for it.

David Bushnell was born and raised in a rural Connecticut farming family in the 1740s and attended Yale in the years right before the Revolution. During his time at Yale he befriended several people who would take part in the uprising (most notably Nathan Hale), as well as friends who would help fund his invention. At a time when war with one of the world’s greatest superpowers seemed inevitable, the young inventor wanted to put his mind to use serving the cause of independence. But in doing so, Bushnell knew that he was putting himself at great personal risk. Submarines were not part of conventional warfare; his actions would be considered those of an insurgent, not an honorable combatant:

The colonies were about to face the world’s superpower, and his vision of a method to counter the British navy had to be kept secret in order to be effective. There was also concern that anyone who became actively involved with this form of clandestine warfare would be considered a traitor and terrorist by the British military courts. Hanging, the primary method for discouraging treason against the Crown, was a likely consequence.

Bushnell envisioned a small craft, carrying explosives, that could be piloted towards an enemy warship. His ship would submerge and then escape detection by using a wooden screw to attach a mine to the hull of the unsuspecting boat. But very little is known about the Turtle itself. The source material consists of only a few notes, letters, and personal accounts – all of which fit neatly in the appendix of this book. Manstan and Frese can’t say for certain what the sub actually looked like. There were no drawings, and what the authors had to go on is the first hand accounts of those who were around or who piloted the machine. What they have gathered can at times be a problematic hodgepodge of conflicting statements, and some of this confusion results from the fact that the Turtle became something of a legend even in its own time. The story of a mysterious underwater boat sailing off the Connecticut coast was something that was passed down from those who had fought in the Revolution:

The voices of veterans from 1776 swapping sea stories in the comfort of Beers Tavern on the New Haven Green are long gone. Memories of a strange vessel that could maneuver under water were passed along to children and grandchildren, inevitably evolving and “improving” with time. It becomes difficult to extract the facts from what has become “once upon a time”.

From what we can gather, the device was oval-shaped and was propelled by a hand crank. The pilots had to be in a physically fit condition, making sure to pace themselves so as not to tire themselves out before they reached their objective. Being able to provide air was a huge challenge in the early design process:

Bushnell’s mission plan was to require that his vessel make its approach to the target “low on the surface of the water “only submerging to attach his mine or “magazine.” When submerged, the pilot would have to rely on air contained in the hull. Bushnell concluded that “the inside was capable of containing the operator, and air, sufficient to support him thirty minutes without receiving fresh air.”

The book starts with the history of the submarine itself. The benefit of Bushnell being a Yale student was that he had access to the vast university library, which had articles dedicated to the subject of making an underwater vessel. To the novice of things nautical there should be a word of caution: a great deal of space in the book is devoted to this history and to Bushnell’s predecessors and their intellectual environments. Another long section of the book covers the actual mechanics of how the Turtle worked (which is important, but necessarily guesswork); we hear about the authors’ tests with replicas and how Manstan did while piloting the sub in the Connecticut River.

The authors’ background makes their authority unimpeachable, but it carries a drawback: they can be laborious. It’s always when we dive back into actual hands-on history that the book picks up steam. Don’t get me wrong: it’s amazing and impressive that they were dedicated enough to create their replica and test it in the Connecticut River, but what should have been one two chapters on such adventures eventually swallows a third of the book. And of course there are pictures of the high school students and their project – further distracting us from Bushnell himself and his project (the book is over-illustrated in general, especially considering its subject is one for which we have no original sketches or blueprints).

Given the formidable reputation of the British navy on the open seas, the prospect of clandestinely blowing up British ships greatly appealed to the leaders of the Continental Army. The original attacks were to be launched from Boston Harbor where the British were occupying the city. But while construction of the weapon was delayed, the warships withdrew from the harbor and New York became the new target. Bushnell’s work did not go unnoticed within the British high command; word spread about a secret weapon that the colonists were making which would be able to attack any ship at anchor:

…“News of Bushnell’s secret weapon had found its way to someone in the network of spies New York Governor Tryon had established…it was only a week later that Tyron dispatched a note to Vice Admiral Molyneux Shuldham. “The great news of the day with us, is now to destroy the navy. A certain Mr. Bushnell has completed his Machine, and had been missing four weeks.

This information almost proved life-threatening. After the failure of the Turtle mission Bushnell was captured with others during a raid along the Connecticut coast .Though he was under false name at the time, his comrades in the army hurried to get him swapped in a prisoner exchange, fearful that the British would learn his true identity and with it his past work.

Most of the Turtle was constructed in and around the Bushnell family farm, and for the most part it was a family affair. Bushnell’s brother Ezra was to be the pilot of the sub, and the design was no doubt tailored to his size. There were several unique challenges that Bushnell had to overcome. How to keep it watertight, how to manage a pressure gage? What would be the life support, should anything go wrong? But perhaps the most troublesome: how would you provide yourself with light, once you were submerged? Bushnell answer was ingenious.

Foxfire (decaying wood, mixed with fungus) would provide enough light for the pilot to see the pressure gage and the target hull in the dark depths. It has been rumored that Benjamin Franklin, who was corresponding with Bushnell at the time, gave him the idea to use foxfire; in an era before electric light, it was the perfect solution:

Bushnell was never specific about the material he used for illumination, only mentioning that he applied “phosphorus” to his compass and depth gauge. Ezra Lee added that both instruments were illuminated with “light wood,” while Gale refers to “fox-fire” and “fox-wood” in his correspondence.

A material that glowed with no flame or heat and could sustain its illumination without any apparent consumption of air was a mystery that begged for an answer. It had been a curiosity among scientific minds throughout history.

With most of the technical problems solved, Bushnell then moved into the testing phase. For this the Turtle was moved to the house of Lt. Richard Sill (whose youngest son was a Yale classmate of Bushnell), which was close to the Long Island Sound and was far enough away from any passing ships to attract attention. But their plan hit a snag: David’s brother Ezra fell ill and a new pilot had to be found. Bushnell turned to Sgt. Ezra Lee, who would pilot the sub on its first operations and become almost as closely associated with it as Bushnell himself.

Ezra Lee was a commanding officer in the 10th Continental Regiment. He had signed up for another mission that was equally dangerous: to destroy British ships (the mission required him slamming a small flaming boat into the British warships with the hope that the fire would spread) – basically, a suicide mission. Lee seemed to be the perfect fit, and he was close in the size and stamina to Bushnell’s brother.

Lee got a crash course of almost ten days on how to pilot the ship, and he was soon headed out to New York harbor. General Washington was debating whether or not he should abandon Manhattan, so there was a sense of urgency about deploying the Turtle in time to make a difference. In the first attack, Lee, inside the Turtle, was towed half way by a whale boat and then set adrift to make his way towards his target. When the moment came, Lee submerged and attempted to attach his bomb. However the screw wouldn’t penetrate the hull:

Once in position, he immediately ran into a problem: “…up with the screw against the bottom but found that it would not enter.” Lee could not secure the wood screw to the hull. He had to think quickly. There was only a half hour of air in the Turtle, but he was determined to try again…It was probably twilight, 5:00 A.M., When Lee surfaced. He had depleted the air inside the turtle…He undoubtedly rested and caught his breath while on the surface alongside the Eagle, pondering his next move.

With all hope being lost for the mission, Lee attempted to make his retreat. When he was spotted and chased by a neighboring ship, he released his bomb to create a diversion, and as everyone watched as the resultant large gush of water exploded into the air, he quickly made his getaway.

Over the next month the Turtle made a handful of attempts to strike at the British fleet. Each one was a failure. The main problem with the operations was that they required large amounts of gunpowder for the mines, at a time when every pinch of powder was needed for less speculative efforts to win the war. Bushnell went on to help in other ways throughout the Revolution, trying to invent other types of explosive weapons. But ironically, he will always be remembered for his failure.

In a letter to Jefferson, George Washington said he thought the invention was “a work of genius.” Perhaps if Bushnell had had a little more time and a little more funding – or just a bigger supply of gunpowder – he and his underwater weapon would have graduated from the footnotes of history.

Kevin Mullins is a playwright based in Boston.