Meet the Turtle: The First Submarine Ever (developed by the Americans to fight Britain)
Key point: Risks lead to innovations.
The world’s first combat submarine was an afterthought from its creator. The revolutionary craft, known as the Turtle for its odd profile, was the offspring of David Bushnell, born in 1742 in West Saybrook, Connecticut. Bushnell didn’t start his career as an inventor, engineer, or even sailor. In fact, he was a farmer for most of his youth. Bushnell’s father passed away at the age of 29 and he ultimately decided to sell the family farm. At the relatively advanced age of 31, Bushnell chose to pursue higher education and entered neighboring Yale College to study mathematics.
Bushnell graduated from Yale in 1775, on the eve of the American Revolution. He was a devout patriot who firmly believed that technology would be the key to winning the war, so he and fellow inventor and Yale scholar Phineas Pratt got to work. The powerful British Navy would have to be treated for the Revolution to be successful, and it was evident that America’s fledgling navy would find it difficult to use conventional tactics. One of the pair’s earliest concepts was an underwater bomb with a time-flintlock detonator, a precursor to modern naval mines. The idea met with considerable skepticism as to whether gunpowder could explode underwater, but Bushnell has successfully proven that it can. The only dilemma the inventors faced was how to deliver the mines, or “time bombs”, to their target. To this end, Bushnell and Pratt developed a one-man hand-propelled submersible vehicle to transport their bombs to an enemy ship. The Turtle is born.
During the turtle’s first trials in the relative safety of Connecticut rivers, another famous colonial inventor, Ben Franklin, was admired from the awkward-looking ship, watching from the shore as the turtle was tested. Bushnell lacked the physical strength and stamina to operate the ship himself, so his brother Ezra volunteered for the job. The Turtle hardly resembled the modern concept of a submarine. It looked more like a beer keg, with an oversized screw protruding from the top, and its propellers and rudder oddly positioned on three different sides of the craft. The ship’s hull looked like two halves of a turtle shell pressed together, hence its nickname. The Tortoise was built of oak, covered with pine tar for waterproofing and held in place by iron bands. Measuring barely 7 1/2 feet tall and six feet wide at its center, it was barely tall enough for its lone operator to squeeze inside. The operator entered through a sealed hatch on top of the submarine, sat on a cross beam mounted inside the vessel, and drove the submersible with cranked propellers, a large one up front and a smaller one above. He maneuvered by means of a rudder at the stern of the ship.
The operator determined where he was going on the surface by looking through a set of glass windows surrounding the hatch. Immersed, he used a phosphorus-lit compass. The turtle could float to the surface and pump cool air through a tight inlet valve, but once underwater, the operator could only keep the vessel below until the air runs out. The vessel dived and surfaced using brass pumps that sucked in or expelled seawater as ballast, as well as using 700 pounds of lead weight, the increments of which could be played over a 50-foot line. and retracted as needed. A decidedly uncomfortable feature of the seawater ballast system was the fact that the Turtle did not have actual ballasts; the incoming seawater simply flooded the floor of the boat, leaving the operator in knee-deep water until it was removed with the pumps as it came to the surface.
Testing the turtle
Once the Turtle headed for its target, the job was only half done – the operator then had to deliver the artillery. The Turtle crank operated an external screw system whose controls were located in the upper chamber of the vessel. Attached to the screw was a waterproof fuse which led to the explosive charge. The load, consisting of 150 pounds of black powder, was designed to float and secured to the outer hull of the enemy ship by means of a removable screw device. Bushnell’s idea was for the operator to sail under an enemy ship, drill the screw into the hull, detach the assembly while adjusting the fuse – a timepiece device with up to 12 hours delay – and s’ fled. The mine would hopefully stay in place while the fuse burned to the charge and exploded, leaving the enemy ship with a hole in its hull. It was a lot to hope for – in the end, maybe too much.
After the British withdrawal from Boston to Halifax, Nova Scotia, in March 1776 following a prolonged siege, General George Washington decided to move most of the Continental Army to New York, which he did in April. Washington realized that New York would be difficult to defend, but its strategic and symbolic importance at least dictated that the effort be made. Fortifications were erected around the city, which was then confined to the southern tip of Manhattan, as well as the Brooklyn Heights neighborhood of Long Island, to the east of the city. The Continentals built Fort Washington in what is now upper Manhattan and built the Battery, an artillery line near New York Harbor. Washington distributed its troops on both sides of the East River and along Manhattan Island. The Americans didn’t know where the British would choose to strike first, but they knew the enemy was regrouping. The Continentals have prepared for the coming assault.
In the late summer of 1776, the British began to arrive in force under the command of Generals William Howe, Henry Clinton and Lord Charles Cornwallis. Their fleet controlled New York Harbor with a vast array of gunships. Daniel McCurtain, an eyewitness, wrote: “The whole bay was full of ships as it could be. I thought all of London was floating. In fact, the force preparing to attack Washington was the largest expeditionary force ever assembled by Britain. Over a period of several weeks, the British army had amassed nearly 32,000 men, including more than 8,000 German mercenaries. Wrongly known as the Hessians – Hesse-Cassel was one of many German principalities at the time – German soldiers actually came from a number of city-states whose rulers sent them to fight in America in return bonus from King George III. Eventually, troop transports began to arrive to transport the Crown Soldiers from their ships from Staten Island to Long Island via Gravesend Bay. Meanwhile, in the waters off New York, Admiral Lord Richard Howe, William Howe’s brother, exchanged fire with US batteries over Manhattan.
The combined British Army and Navy threatened to push Washington and its Continental Army to the Hudson River and take control of the entire Hudson River Valley. This would effectively split the colonies in half, which was Howe’s grand strategy to suddenly end the Revolution. As his plan became clear, it also became clear that the Americans desperately needed to break through the British naval blockade. During this untenable situation, the Turtle entered service for the first time, with the monumental task of breaking the blockade by attacking the British fleet while at anchor.
After a year of training, Ezra Bushnell was ready to pilot the Turtle, but the night before the mission he fell seriously ill with a fever. The mission had to be cleaned up and a new pilot had to be trained in a considerably shortened timeframe. Bushnell retreated with the turtle to Long Island Strait and quickly sought a new volunteer. An Army sergeant named Ezra Lee, from Old Lyme, Connecticut, was chosen to maneuver the submarine and deploy the mine. It was then at the end of August and the situation for the American forces had become even more serious. Much of Washington’s army had been lured into a trap, and the British invaded Long Island on August 26, brutalizing Washington’s troops and forcing them to withdraw to New York. Bushnell knew time was running out. He cut Lee’s workout short and returned to New York.
With hesitant preparations at best and Continental General Israel Putnam’s staff watching, the Turtle embarked on its historic mission at 11 p.m. on the night of September 6, 1776, with meager hopes of success weighing heavily on the craft, its inventor and its pilot. . After several grueling hours of start-up, Lee and the Turtle finally reached HMS Eagle, Howe’s flagship, which was anchored at the approximate current location of the Statue of Liberty. Before dawn, Lee managed to submerge himself under the keel of the ship undetected. Bushnell and his team knew that fixing the mine would be a difficult task under any circumstances. British warships of the day protected their hulls with a process called “etching,” coating the hull with a thick compound of tallow, sulfur and resin. This process repelled boatworms, barnacles, and other destructive sea creatures, but did not prevent weeds from growing through the hull or other unwanted growths from attaching to it. Unfortunately for Bushnell and his team, the British had discovered that the “copper,” covering the hull with a thick plate of copper, protected their ships from all forms of maritime threats. Most of the fleet was being coppered during the War of Independence, and the Admiral’s flagship would surely have been one of the first to receive such an upgrade. This unfortunate development most likely explains Lee’s inability to reattach the mine to the Eagle. It made two strenuous attempts, but struck the metal each time and failed to penetrate the hull with the manual screw. Exhausted, unable to attach explosives and short of breathable air, Lee had no choice but to abandon his mission.