The first Turtle was named for the marine reptile; the second for Turtle Town, a small unincorporated town in Polk County, Tenn.
(Submarine: t. 1 (approx.); 1. 7'6"; dhp. 6'; s. 2 to 3 k.; cpl. 1; a. 1 "torpedo")
The first Turtle was designed in 1771 by David Bushnell, a Yale student, and built with the help of his brother, Ezra Bushnell, in 1775 at Saybrook, Conn. The submersible was named Turtle because Bushnell thought that this unique craft bore some resemblance to "two upper tortoise shells of equal size, joined together."
Conceived as a means of breaking the British blockade of Boston harbor, the submersible embodied four basic requirements for a successful military submarine: the ability to (1) submerge, (2) to maneuver under water, (3) to maintain an adequate air supply to support the operator of the craft, and (4) to carry out effective offensive action against an enemy surface ship.
Turtle could be made to submerge by simply flooding her bilges with sea water. To surface, the man operating the submarine would pump out the bilges. A crude conning tower, fitted with round, glass ports projected some six or seven inches above the surface of the water. This arrangement allowed the operator to see where he was going and permitted light to illuminate the equipment necessary to operate the submarine. When submerged, Turtle was illuminated by instruments made of a phosphorescent wood known as "fox fire."
Maneuverability in the horizontal plane was achieved by a hand- or foot-cranked propeller fitted at the bow. Ascent or descent was made possible by a second propeller fitted just ahead of the low conning tower arrangement. It was possible for Turtle's operator to propel the craft forward by utilizing the foot-treadle to operate the bow propeller while simultaneously using the hand-operated second propeller to move the craft up or down. Steering was accomplished by a tiller. The combination of the craft's shape and the ballast load—700 pounds (500 fixed and 200 detachable)—gave Turtle a low center of gravity and made her quite stable.
Air was supplied by a pair of tubes fitted through the conning tower hatch. Valves in these pipes would automatically shut them while the vessel was submerged. The tubes themselves actually resembled a crude snorkel arrangement.
As to the craft's offensive capability, Bushnell invented a "torpedo" which would be carried into action and then jettisoned to be secured against an enemy ship's hull. The "torpedo" was an egg-shaped casing filled with 150 pounds of gunpowder and fitted with a rudimentary clock-work detonator. Fitted piggy-back style abaft the conning tower, the "torpedo" was to be fastened to a bolt screwed into the enemy's hull. The clock-work mechanism—set for about an hour's time —would then set off the charge, hopefully after the submarine had cleared the area. Apparently, during Turtle's trials, Bushnell tested this aparatus against a hulk in the Conecticut River.
Bushnell attempted to keep his strange work a secret and completed Turtle in late October or early November of 1775. However, word leaked out, due probably to the Tory sympathies of a local postmaster who would periodically read letters written by one of Bushnell's friends, who knew of the invention. To the British, the craft seemed potentially dangerous.
Encouraged in his endeavors by men like George Washington, Thomas Jefferson, and Benjamin Franklin, among others, Bushnell continued to perfect his device —almost entirely with his own dwindling funds. Although Bushnell planned to deploy Turtle to Boston, that operation was obviated when General Howe evacuated the city on 17 March 1776 despite his successes at Breed's and Bunker hills and withdrew north to Nova Scotia.
After reinforcements arrived, Howe set sail from Halifax on 10 June and began landing his troops at Staten Island, N.Y., on 5 July. Bushnell accordingly offered the services of his submarine to General Washington who provided the young inventor with funds and "other aids to carry his plan to execution."
Bushnell had planned to use his brother Ezra as the operator of the submarine when she went into action against the British. However, Ezra fell ill shortly before Bushnell had planned to launch his invention's combat career. With Ezra's illness, there was no one who knew enough to operate the craft outside of Bushnell himself. Bushnell accordingly approached General Parsons of the Connecticut militia to call for three volunteers to undergo an accelerated training program. The one volunteer who apparently distinguished himself by his abilities was Sergeant Ezra Lee.
Meanwhile, as Turtle underwent minor alterations over a 10-day period, the military situation in the New York area changed dramatically. Late in August, Washington's army retreated from Long Island, as Howe occupied Governor's Island. The time to prove the submarine's effectiveness had come.
Bushnell picked out the imposing 64-gun HMS Eagle—the flagship of Admiral "Black Dick" Howe (General Howe's brother)—as his choice for a target. This vessel, under the command of Capt. Henry Duncan, lay moored with the rest of the large British squadron to the north of Staten Island.
Sergeant Lee clambered down the narrow conning tower hatch late in the evening of 6 September 1776 and, at 2230, set out on his mission. Towed downstream "as nigh the fleet they dared," Turtle was cast off, undetected. Lee hove about and rowed for nearly two and one-half hours before the tide slackened. He rowed under the stern of his target and, as he neared Eagle's imposing bulk, he could see men on deck. The sound of their voices wafted down to his ears in the muggy pre-dawn darkness. Once this close, Lee shut all doors and prepared to descend beneath the royal man-of-war's hull.
Turtle sank deeper and came up under the hull. However, his efforts to attach the "torpedo" to the ship's hull were frustrated by copper-sheathing, or marine growth, or perhaps merely a hard spot in the hull which prevented the drill from boring into the ship bottom. Lee tried again after failing in the first attempt but apparently lost control of the craft. Turtle "immediately rose with great velocity" and broached two or three feet from Eagle's side. Fortunately, the sergeant's craft "sunk like a porpoise" and submerged before a chance glance from British sailors on deck revealed his presence.
Lee initially thought to try again but decided against it. Daybreak might bring the chance of his being discovered. Deeming it "the best generalship" to clear the area, he retreated as fast as he could, traveling mostly submerged but surfacing every few minutes to get his bearings. The tide, however, made the passage difficult. Soon, some 300 or 400 British soldiers clambered atop the parapet on the fort on the English-held Governor's Island and saw the little craft steering a "crooked and zig-zag" course past the island. Presently, curiosity spawned the desire to take action, and a 12-oared cutter put out from shore with six men in it.
Lee eyed them cautiously and waited until they closed to within 50 and 60 yards. He then "let loose the magazine (torpedo) in hopes that if they should take me they would likewise pick up the magazine, and then we would all be blown up together." As Lee later recorded, however, "But as kind Providence would have it, they (the British) took fright," and returned to the island, to the sergeant's "infinite delight."
Turtle and her intrepid operator were eventually towed to safety by American boats which spotted the submarine. The "torpedo" soon drifted with the tide past Governor's Island, directly toward the anchored mass of British ships—both warships and transports. Suddenly, the "torpedo" blew up "with a tremendous explosion, throwing up bodies of water to a great height." This succeeded in alarming the British enough to cut their cables and slip downstream to the southward of Staten Island.
Two subsequent attempts to blow up British ships followed. Each, conducted from Fort Lee "(Manhattan having fallen later that summer), was unsuccessful. On 9 October 1776, two British frigates, HMS Phoenix and HMS Roebuck, accompanied by the 20-gun HMS Tartar and three tenders, stood up the lower Hudson. They ignored the futile cannonade from Forts Washington and Constitution and quickly disposed of a small Continental squadron. Among the American ships lost was the small sloop carrying Turtle. Lee and Bushnell both escaped injury and reached shore. The first American submarine, however, sank to the bottom of the Hudson.
Although soon recovered, Turtle saw no further service. Her eventual fate remains a mystery.