Horizontal paddle wheels and the Germ
The use of early steam engines for powering ships, after a few limited experiments, became reality with Fulton's North River Steamboat (the "Clermont") on the Hudson River in 1807. She carried sails on two masts, yet under power from a nominal 19 horsepower engine could achieve between four and five miles per hour (6-8 k/h.) Her commercial success led to rapid commercial expansion in the USA and Europe. Navies as well as commercial shipping became interested. While several ships experimented with "screw" or "propeller" designs, most used paddle wheels, predominantly side-wheels, some stern-wheels. Trials and developmental experiments took place in salt water, coastal and trans-oceanic, as well as on rivers, canals and lakes; these ships were nearly all equipped as sailing vessels, with steam as auxiliary power.
For side-wheels, two major difficulties were proven to be a limiting factor: firstly, if the ship rolled or heeled, one paddlewheel would be too deep, while the other would barely be in the water or could even totally emerge, leading to great inefficiency, if not damage to the mechanical components; and secondly, for naval vessels, not only were the wheels and steam engine exposed to potential enemy fire, but also the decks amidships could not be used to mount guns. It was also often noted that canal banks could erode due to the wash from the wheels.
By the late 1830s competition amongst designers to utilize steam power more effectively and efficiently, in line with the rapid development of the steam engine itself and the propeller, led to many novel concepts.
The Germ Experiment [1]
US Navy Lieutenant William W. Hunter, stationed in Norfolk, and fellow inventor and partner Benjamin Harris had worked on correcting these flaws for some time prior to being granted U.S. Patent no. 2004 dated March 12, 1841, antedated November 2 the previous year. Hunter and Harris devised a gearing system that allowed the paddlewheel to be mounted horizontally under water, rather than vertically alongside the ship. The paddlewheel was enclosed in a casing with only that portion of the blades exposed which was needed to propel the vessel. Note that in the patent drawing shown here that "AAA is the water-line; BBBB, the shield deck faced with iron ... joined and secured entirely round the vessel at a given distance below the water line, out of the reach of shot." This left the above-water portion of hull clear to mount guns as usual, while simultaneously protecting the propulsion system from gunfire. The arrangement also promised to cut down on the size of the wake of steamboats used in canals. It was a simple but adequate solution to a number of known problems with paddlewheel steamships. Following the death of Harris in late 1840, Hunter sought financial backing to turn his idea into reality.
Myer Myers, third son of early Norfolk merchant Moses Myers, proved to have the money Hunter sought. Fortunately for historians, much of the correspondence between the two men is held by the Chrysler Museum of Art. On December 22, 1840, Myers signed a contract with Hunter and the heirs of Benjamin Harris. In return for $3,200, to be used to build a small steamer capable of showing the efficacy of horizontal wheels, Myers would receive one-third of any returns from the U.S. patent. Under Hunter's direction, construction began quickly at the Gosport Navy Yard. The result, launched in early Spring 1841, was the Germ. Although Hunter and Myers retained ownership, the steam boat was taken into Federal service. She was what today would be referred to as a technology demonstrator. Germ was small, "believed to be the smallest steam vessel ever sent to sea." She is normally given as 60' in length, 9' beam and 2' draft, but references to 50' and 52' in length, 11' and 12' beam (perhaps including the protruding parts of the wheels) and a draft of 28 inches can be found. Whichever set is true, she was, as Philadelphia's United States Gazette described her, "not much larger than the launch of one of our vessels of war." A six [eight? - see below] horse-power steam engine "like those used in locomotives" provided power.
Her name, in those pre-Pasteur days, meant "that from which anything springs or starts" and Hunter planned to sow that seed with a series of demonstrations along the Atlantic Coast. Beginning in March 1841, a number of trips around Norfolk harbor were followed by two excursions through the Dismal Swamp Canal. In June, Secretary of the Navy George Badger ordered Hunter to bring Germ to Washington. The tiny vessel arrived on June 18 after a trip lasting 32 hours. She had made an average speed of nine miles per hour. As The Madisonian reported; "This is but a germ, it is believed, of what she can do." After two days of demonstrations, Germ returned to Hampton Roads. The return trip took just 30 hours. Secretary Badger discharged the vessel from the service of the government, but assured Hunter that "the only reason for the order ... was that as the Germ had already been used under a sufficient variety of circumstances for testing, so far as that vessel would admit, the value of your plan, I did not feel at liberty to retain her ... for a purpose that had already been accomplished." With Germ back under their control, Hunter and Myers began serious efforts to make a profit from the technology. Myers used his network of European trading partners to acquire patents on "Hunter's submerged propellers" in France and England. Overseas, however, Myers did "not think [Harris'] widow's name should be used as she is not entitled to any interest, contributing not a cent. She has no means to aid in furtherance of the object there." Hunter decided it was time to stress the variety of uses for which the system could be employed. On July 3, Germ was used to tow a warship from Gosport to the anchorage off Hospital Point. The vessel made another trip through the Dismal Swamp Canal to Elizabeth City and back. In late July, Hunter sent Germ north. In July, she arrived in Philadelphia where Hunter demonstrated her capabilities to the directors of the Delaware and Chesapeake Canal. Commodore Charles Stewart also took an excursion aboard her as did members of the Franklin Institute, "the scientifics" as Hunter called them. The real focus of the trip, however, was New York. The stop at Philadelphia, Hunter wrote Myers, had been made so that "impressions made here will strengthen our interests in New York."
In July 1841 [2], it was reported: "Steamboat Germ – On Monday morning last, 26th inst., the newly invented steamboat Germ, arrived at the Navy Yard, Philadelphia, having come from North Carolina through the Dismal Swamp and Chesapeake and Delaware Canals. This boat was built by Lieut. Hunter, of the Navy, on a plan of his own invention: She is not much larger than the launch of one of our vessels of war, being but sixty feet long, with twelve feet beam, and sharp at both stem and stern. The great improvement is in her paddles, which are below the surface of the water, and are in a horizontal position, the paddle projecting about a foot from the side of the vessel. From the centre of the paddle wheel a bar rises, perpendicularly, connecting at right angles with another bar attached to the engine, and lying parallel with the wheel. The force of the engine is of about eight borse power, and the boiler in use is similar to that used in locomotives. With this engine which is a very imperfect one, the boat has been driven, in very bad weather, at the rate of nine knots an hour. The invention seems admirably calculated to promote the safety of vessels of war during an engagement; the wheels being so far under the water, as to be in a great measure protected from the shot, and it likewise seems well adapted to canal navigation, in as much as little or no surf is made by the motion of the wheels, the vessel gliding along easily and smoothly, without creating waves. She is on her way to N. York, Lieut. Hunter being desirous of introducing the invention into the packed ships at that city."
The New York visit proved to be a public relations success. Bennett's Herald (the New York Herald) wrote on August 7, 1841 : "The working of the Germ in our harbor yesterday was admirable. Crowds flocked to the Battery, to see her, and all were delighted with her graceful and noiseless movement through the waters. She came close to the Battery wall, Capt. Hosken and ourselves jumped on board; she went round and round the North Carolina, like a snake, swift and still, and the officers on board were puzzled to make her out. At last their band struck up 'Hail Columbia,' and cheered her. The Germ then returned to the Battery, landed her two passengers, with Lieut. Hunter, and proceeded to the Navy Yard." More important than newspaper editors, however, were the passengers Hunter had taken out earlier that day: Commodore Vanderbilt and the other directors of the Erie Canal. They were sufficiently impressed to offer Hunter and Myers $10 per ton for the patent rights to construct canal boats with submerged propellers of Hunter's design. Other offers came in: for vessels to run out Boston, for a vessel to work between New York and Albany. The Boston and Albany ships, both at 250 tons, would bring in $2,500 each in patent rights. As Hunter wrote "Our affair is determined to yield an immense profit, almost incalculable."
Hunter felt yet more money could be made in Great Lakes navigation. "The Lakes offer a vast field & I leave here on Monday to reap it," he wrote Myers on August 14. Germ proceeded up the Hudson to Troy and the Erie Canal. The Baltimore Sun wrote on Saturday, Aug. 21, 1841: "THE GERM – The Troy Whig says that Lieutenant Hunter's experimental boat, the Germ passed through the canal at the rate of about five miles per hour, and the wave she created was no greater than that produced by an ordinary canal packet. The Germ is on her way to Oswego, whence it is intended to proceed across Lake Ontraio to Kingston" thus confirming the usefulness of Hunter's design for canal travel.
The New York Tribune reported on Friday, Aug. 20, 1841 that "Lieut. Hunter’s steamboat Germ, left Albany on Wednesday for Syracuse and Oswego, via the Erie Canal."
After returning to Norfolk, she became the first steam vessel to have gone from North Carolina to the Great Lakes via the Erie Canal and back. The Navy had been sufficiently impressed with Hunter's work to authorize construction of a larger vessel, Union of 900 tons. Work began at Gosport shortly after his return. This left Myer Myers with question of what to do with Germ. In the summer of 1842, Myers decided to employ the vessel as a packet in the North Carolina Sounds. For a while, it appeared he would be able to obtain a subsidy to run mail between Windsor and Edenton. The project fell through because of his unfortunate choice for Germ's master. Myers wrote a friend in Elizabeth City on November 14, 1842, "Captain [Edmund] Chaytor was recommended to me as a capable, correct & sober man. Was ever a person more imposed upon? 'Tis much to be regretted some friend of mine seeing his drunken habits in North Carolina had not favored me with a hint. Such an act of friendship would have served the owners of the Germ money and an infinity of trouble. As yet I have had no settlement with him. In fact, I have not seen him for three weeks. Nothing can be got from him. I am not bound for his debts & fear the assistance of money from yourself and others tended to encourage the grog shops in their designs upon him. Myers dispatched another captain to bring Germ back to Norfolk warning him "to stop as little as possible at the towns as it is probable that Chaytor has contracted debts at each ... If it is necessary to stop for wood, I presume it can be had at the villages."
Once Germ returned to Norfolk, there is no firm record of how she was employed. That did not mean, however, that Hunter slowed his efforts to turn a profit on her. In August 1842, he approached the Secretary of the Navy Abel P. Upshur with a plan to have the Navy buy the vessel to continue experiments with larger engines. Upshur, a college classmate and close friend of Myers' older brother Samuel, was in favor of doing so. Regretfully he told Hunter that "Congress had so hampered him as to render it impossible for him to do as he desires." Next in 1843, Hunter unsuccessfully approached the Coast Survey Board in an effort to get them to suggest Germ's purchase to Congress. In October of that year, he tried a different rationale. He approached the new Navy Secretary David Henshaw with the idea that Germ should be bought to be used as a test bed for the radical concept of developing a steam-powered cannon. Henshaw again pleaded Congress-induced poverty. In March of 1844, Hunter succeeded in getting a bill introduced in both houses of Congress for the expenditure of $13,000 to purchase Germ and her equipment. The bill failed.
In 1845, Hunter was in New Orleans. There, he tried to interest friends in purchasing Germ as a school ship to train steamshipmen. In the meanwhile Germ's idleness led to a deteriorating material condition. Hunter had asked fellow officers at the Gosport Navy Yard to use sailors from the receiving ship Pennsylvania to maintain Germ. Their efforts were disappointing. On February I, 1845, he wrote Myers "I was also shaken to learn from you that Porter and Farragut whom I had written to take charge of the Germ had permitted her to be sunk." In all probability, the vessel's watertight cofferdam around her paddles had leaked. One assumes this was not a true reflection of the abilities of two officers who were destined to become the U.S. Navy's first admirals. The ship was raised, and Hunter recommended Myers maintain her by his wharf to keep a closer eye on her. In 1848, Myer Myers closed the vessel's account with Hunter after receiving a last payment of $163.39 for Germ's expenses. The final end of the tiny vessel is not known.
The end of Germ did not mean the end of Hunter's technology. On August 5, 1845, Myers had written to the London lawyers who handled the English patent application:
"Our Government built on our plan the War Steamer Union at [900] tons. She was found to move with all her armament etc. on board upwards of 10 knots per hour. All the other advantages of the submerged horizontal paddles were so obvious that our Government immediately ordered 5 iron steamers built with our propellers for Revenue Cutters each [400] tons. Three of them have been launched [Bibb, McLane and Spencer [3]], two are not yet completed [Dallas was finished in 1846, the other not finished]. The Government has also in the course of construction with our propellers a naval iron steamer of 1100 tons [Allegheny] that will be launched in about 6 months [actually completed in 1847 with $10,320 going to Hunter personally for his patent rights]. The boilers of the Steamer Union after a little service were found ineffective & that vessel performed but little service & was laid up. They contemplate giving her soon a new boiler, etc.
All the Revenue Cutters were modeled upon the same plan & it was found very defective, those vessels not having sufficient beam. There was another miscalculation & all these vessels being alike not one has been able to establish our propellers. The 1100 ton ship that will be launched in about 6 months is all right & she is relied on to establish the propellers and get them permanently adopted in our Navy. This vessel it is contemplated Will be exhibited in England & other parts of Europe under the command of one of the patenters - a naval officer [Hunter]. If this vessel proves as we confidently believe she will, proves our propellers to be far superior to all others & they become permanently adopted, she will greatly enhance the value of our patent."
The reality was less sanguine than Myers' description. Before the experiment ended, the Government had taken possession of, at one time or another, nine vessels equipped with the Hunter wheel. Three went to the Navy, three went to the Revenue Service, two to the Coast Survey, and one to the Topographical Engineer Corps in the Great Lakes.
Conclusion
However, none of the government vessels constructed with Hunter's submerged propellers was successful with the exception of a small prefabricated survey vessel built for the Army Corps of Engineers and assembled in Buffalo. Colonel Abert [later renamed Surveyor in 1849] conducted her work until 1875 when she was sold out to become a St. Clair River ferry. By 1849, all others had been converted to side-wheels or screw propellers or were out of service. Even the Margaret Kimble, a 100 ton iron freighter and passenger steamer built in 1844 for Myer Myers was switched to paddlewheels in 1846. The reason for this failure is found in the problem of mechanical efficiency. Too much power was lost in the slip of the paddle (the difference between the theoretical distance moved by the paddle and actual movement of the ship). In reality, Hunter's horizontal wheels were moving not only the ship but also the water contained in the paddle casings. According to early steam historian Donald Canney, for Hunter's design, the slip figured to be 50- 70%. By comparison, Ericsson's screw propeller used on Princeton was only 23 - 46%. This resulted in higher comparative fuel consumption. Allegheny's consumption of coal was seven times that of the side-wheel frigate Mississippi. Another factor was the effect of the unusual hull shape required by Hunter's wheels on sailing properties. Despite all this research on steam propulsion, sail were still considered to be the primary form of propulsion. The Navy eventually built most of its ships using Swedish-American inventor John Ericsson's propeller. This invention probably had a bigger impact on naval history than Ericsson's more famous ironclad project.
Why then did the Navy seemingly waste so many scarce resources on an idea that seems ludicrous in retrospect? The answer lies in the nature of technology at a time of rapid change. In the absence of a clearly correct choice, many alternatives will be tried until one proves dominant. The Navy in the late 1830's and early 1840's was unhappy with the conventional answer to steam propulsion, side-wheelers. Such ships were vulnerable to enemy shot and had exceedingly bad sailing characteristics when not under power. It was not obvious that the screw propeller would become dominant. Indeed, when Union first went to sea, it was felt by many observers that she could run circles around the screw propeller-driven Princeton. From New York in August 1841, Hunter had written Myers "Everyone here says we beat Ericsson's propeller." Nor were Hunter's and Ericsson's designs the only alternatives put forward. Canney's fine work, "The Old Steam Navy", lists at least six other variations on steam propulsion that were considered by the Navy in this era. But, as always, partisans for each alternative voiced their support until external circumstances clearly identified the "right" choice.