Turtle: David Bushnell's Revolutionary Vessel

by Roy R. Manstan, Frederic J. Frese

“Built at the dawn of the American Revolution, the one-man wooden submersible, its creation, and its attacks on the Royal Navy in New York harbor is a story still surrounded in mystery. In this much anticipated book, Roy Manstan and Frederic Frese bring the story of Bushnell’s revolutionary underwater machine to life.” - JERRY ROBERTS, Director, Connecticut River Museum

At the onset of the American Revolution, the British expected to quell the rebellion quickly with a show of overwhelming force. In an experiment in asymmetric warfare, David Bushnell created the first submarine vessel designed specifically “for the destruction of vessels of war.” On a quiet September night in 1776, sergeant Ezra Lee maneuvered Bushnell’s strange little craft out from Manhattan and into the midst of the greatest naval fleet ever assembled in the Americas. Lee’s goal was to sink the British flagship HMS Eagle by attaching a powerful explosive to its hull. Although the mission was unsuccessful, Bushnell’s concept of submarine warfare was considered by George Washington to have been “an effort of genius.”

David Bushnell was raised in the town of Saybrook at the mouth of the Connecticut River. More than two centuries later, another Turtle would be launched into the same river within sight of Bushnell’s first forays with his vessel during the summer of 1775. Under the direction of technical arts teacher Frederic J. Frese, students at Old Saybrook High School created a working replica of Bushnell’s submarine, facilitated through an education partnership with the Naval Undersea Warfare Center in Newport, Rhode Island, where Roy R. Manstan was a mechanical engineer and Navy trained diver. With twenty-first century submariners at the helm, the Turtle replica was subjected to a series of operational tests at the Mystic Seaport Museum in Mystic, Connecticut.

In Turtle: David Bushnell’s Revolutionary Vessel, the authors provide new insight into Bushnell’s “engine of devastation,” tracing the history of undersea warfare before Bushnell and the origin of the many innovations Bushnell understood would be necessary for conducting a covert submarine attack. The knowledge gained from testing the Turtle replica enabled the authors to speculate as to what America’s first submariner Ezra Lee experienced that September night and what may have caused the attack to fail.

Genres: History, American History

372 pages, Hardcover

First published May 1, 2010

Reviews

[Tom Sterling · Rating 5 out of 5]

In 1776, Saybrook, Connecticut resident David Bushnell created The Turtle; the first one-man submarine designed to destroy a British warship that was blockading New York Harbor. The mission failed.

In 2007, supported by technical arts director Frederic J. Frese, and Navy Diver and Mechanical Engineer Roy R. Manstan, students at Old Saybrook High School reverse-engineered, built, and tested a working, full-scale replica of The Turtle to see if it could be done, and to try and determine why the mission failed.

Authors Manstan and Frese do a wonderful job of telling this fun, interesting, and true story about ingenuity and perseverance that spans across two centuries.

Five stars!

[Joe White · Rating 4 out of 5]

review Turtle: David Bushnell's Revolutionary Vessel
2/16/15 9:00 pm

The focus of this book is on the operational capabilities of a replication vessel built to measure the effectiveness of David Bushnell's designed and built prototype human powered submarine as used near the date of Sept. 6-9 of 1776 in New York Harbor against the British navy.

This book contains as much literary reference material as is probably available with regard to this historical incident. There are references to written contents regarding the designer, operators, Continental Army disposition, British Warship disposition, some of the ships in action in various harbors, army ranks, probable building and testing sites, treatment of prisoners, costs, maps, geographical measurements of locations and mileage involved for travel, harbor depths, and water measurement salinity.

There are photocopies of actual letters to individuals, and many quotes of snippets of text recorded over several years from primary participants to document surmised estimates of the vessel's operational design, effectiveness, logistics, and costs.

As a rough estimate, 60 % or more of the text is historically oriented documentation.

Approximately 40 % or less of the text is presented as a project planning document consisting of:
1. testing goals.
2. design decisions made in the replication with the supporting logic for those decisions included:
hull design, dimensions, ballasting, propulsion, on-board instruments and illumination, logistical transport weight and methods, seating position, and arrangement of mechanical devices.
3. physiological measurements regarding the size and capabilities of the operators, operating time-lines versus physical stamina, vo2 rates, pulse rates, physical positioning for operating measurements with regard to leg, hip, arm, and wrist joints and strengths.

This was not an attempt at a recreation of the attempt to sink a British ship.

There was a very limited testing time window, of apparently only 3 days using the physical replication.

The actionable account is strictly a series of tests against design build considerations, each made as an individual measurable test. For example, the decision to use a type of propellor for both horizontal and vertical thrust, the closest prop shape estimated based on historical evidence, and the ability to test various blade attack angles was stated. The actual efficiency of the assembled propulsive blades in the water was done in a constrained manner to get data measurements with regard to thrust power and the exertion required for that thrust. The hull drag resistance in the water was measured with drag tests. Propulsion power was measured statically in the water under constraint, so that the force could be measured as power versus rpm. The vertical propulsion capability was measured independently from the horizontal capability. Test were done in the day time within a constrained lift area of a shipyard.

There was no discussion of the actual construction of the boat. (ie no sailor sagas of steam bending, plank on frame attachments, iron banding hammering, etc.) Those steps were just the outcome of the design decisions presented.

The book is sizeable for such a limited focus due to the documentation surrounding decisions and the historical material presented. The actual testing decisions and design paradigm is written in a very brief business-like format.