The early days of propellers
The following article is adapted from an article by Commander H. F. D. Davis, U.S.N. "The Early History Of The Screw Propeller" [1]. The author relies heavily on the writings of John Bourne, a contemporary of the early inventors and builders, and who gained a reputation as a historian of engineering science.
See also The early inventors of propellers and their patents.
In marveling at the progress made in the field of transportation it is of interest to note that the first successful screw propellers for ships were put into use just a little less than one hundred years ago [This was written in 1931. Ed.]. The story of the successful introduction of these propellers, which now make possible the high speeds of modern ships of both water and air, can hardly be told in a more interesting way than by a man who was an eye witness and who made himself a historian of some of the important engineering events of those times; accordingly John Bourne [2] will be quoted at length.
In taking up his story he writes: "The screw propeller is, in all probability, a very ancient contrivance. In China it is said to have been known for ages; but in European countries the idea of a screw propeller appears to have been derived either from the windmill or smokejack, or from the screw of Archimedes — an instrument much used in some countries for raising water. The windmill and smokejack both appear to be ancient contrivances." A smokejack, is "A mechanism for turning a roasting spit: operated by the ascending combustion gases in a chimney."
James Watt's successful steam engines had stimulated the development of means for propelling ships; the earliest thoroughly successful application, using paddle wheels, being that of Robert Fulton in the Clermont which made her epoch-making trip up the Hudson on August 7,1807.
After recounting the probable very early history of the windmill and smokejack, Bourne takes up the more modern developments. Of interest to navigators of today is an invention of Robert Hooke, a prolific inventor of those times:
On November 28, 1683, Hooke showed to the Royal Society an instrument he had contrived and shown to some of the members twenty years before, by which the way of a ship through the water, or the velocity of a river, could be measured. This instrument, of which the most essential part was a screw turned by the water, was designed, not merely to keep account of the distance run, but also of the amount of leeway under all the tackings of the ship. Only the vane or fly of the instrument was shown to the society and it appears to have constituted the original of the patent or Massey's log, now coming into use; but Hooke's instrument was more perfect than the present patent logs, as it took cognizance of the leeway. Hooke had also, it is understood, discovered a method of enabling his log to take cognizance of ocean currents, which no existing instrument can do; and he is also said to have discovered a method of constructing an instrument capable of tracing upon a map or sheet of paper the course of a carriage on a road, whatever windings it might make: but these with many of his other inventions are now lost.
From Hooke's time until 1836 when Francis Pettit Smith on May 31 took out a patent "for an improved propeller for steam and other vessels" and John Ericsson on July 13 took out a patent "for an improved propeller applicable to steam navigation," there were many proposals put forward. Many of the mechanisms were to operate like a duck's foot or the tail of a fish; others consisted of screws and paddles in various arrangements and locations relative to the ship; water jets and air jets were the basic ideals of others.
John Bourne sums up the situation in 1836 as follows:
Many of the early plans I have described were susceptible of beneficial, practical application. Several of them, in fact, were tried. Nevertheless, up to the time at which Smith and Ericsson appeared, no permanent or practical progress had been made in screw propulsion.
In 1836 when their patents were taken out, no vessel was in existence which was propelled by a screw. Experiments, indeed, had been made both in this country, in America, and in France, showing that by means of a screw, a vessel might be propelled through the water. But the recollection of these experiments had, in great measure, died out, and what remained of it operated rather as
a discouragement than a provocative to enterprise, since it carried the presumption that, if the mode of propelling by screw, when tried, had been found satisfactory, it would not subsequently have been relinquished.
After mentioning the names of several men who had met with some success, notably Lyttleton, 1794, Shorter, 1802, Stevens, 1804, Bourdon, 1824, Brown, 1825, and Waddell, he adds in a judicial tone that "these inventors appear to have been deficient in that persistency of effort which is the main requisite of progression, and probably, too, circumstances had not ripened sufficiently, at the time they worked, to enable such a quality to produce its natural results." Finally:
Whatever theory, however, we may form upon this subject, it is at least certain that up to the time at which Smith took up the subject in this country, and Ericsson in America, [3] no practical progress in screw propelling had been made; whereas, since that time, and mainly in consequence of their successes, the progress of the art has been rapid and uninterrupted. I take no account in such a retrospect of small questions of detail. I do not think it necessary to ask whether the particular propellers, by which this revolution in the art of steam navigation was accomplished, were better or worse intrinsically than other propellers, whose existence had been limited to paper or to the sphere of Polytechnic toys or ineffectual experiment. It does not appear to be a reasonable expectation, that the best possible forms of screw should be those which were first practically applied, and it was a fair presumption that better forms than any known in the infancy of the system should afterwards be discovered. But as such a discovery could not diminish the credit due to Messrs. Smith and Ericsson for having practically introduced this new method of propulsion, so neither should it diminish the emoluments properly accruing from their successful exertions.
This pronouncement was evidently an effort to settle, at least to a degree, the controversy which raged for many years throughout the world, over the question as to whom credit was chiefly due in this matter. It is evident from the foregoing that the early history of the screw propeller is bound up in the life histories of the two main personages, Francis Pettit Smith and John Ericsson, and their associates and that the stories of these two men will be somewhat parallel with possible points of contact. The further history will be given in two parts, English, centering around Smith, and American, centering around Ericsson.
Francis Pettit Smith and the Screw Propeller
Francis Pettit Smith was born at Hythe in Kent on February 9, 1808. He was the only son of Mr. Charles Smith, the postmaster of Hythe for upwards of forty years, and when he grew to man's estate he adopted the business of a grazing farmer. He had all his life been addicted to the construction of boats and had contrived and tested various modes of propulsion; but in 1834 a model which he had constructed, and which was propelled by a screw driven by a spring, answered so well that Mr. Smith concluded that a screw would be a better propelling instrument than paddles and he thereupon entered upon the course of experiment and demonstration which ended in the general introduction of the screw as a propeller. During this time I was an attentive observer of Mr. Smith's proceedings, but I only became personally acquainted with him in 1843 when the scepticism of the engineering community had already been shaken by his successes.
Smith in the spring of 1836 obtained the assistance of a banker, Mr. Wright. Even in those days a banker appears to have been very necessary to the success of an enterprise. The model boat, with a wooden screw, was exhibited in operation upon a pond at Smith's home, and "at the Adelaide Gallery in London. At the latter place it was inspected by Sir John Barrow, then secretary of the Admiralty, and an offer was made by Messrs. Harris and Bell, of Alexandria, to purchase the invention for the Pasha of Egypt, but this offer was declined."
Next a boat of "six tons burthen" and six horsepower was built, and exhibited in operation on the Paddington Canal and the Thames after November 1, 1836, and in 1837. The wooden screw at first had two turns, an accident in February, 1837, serving to indicate that the length could be reduced to advantage. Having struck a submerged object which knocked off about one-half the screw, it was noticed that the boat immediately speeded up and gave better results.
In order to demonstrate seagoing qualities, even in a boat so small, a voyage was made in September, 1837, touching at the following places in turn: Blackwall, Gravesend, Ramsgate, Dover, Folkestone, Hythe, Folkestone; returning to London on the twenty-fifth "in weather so stormy and boisterous, that it was accounted dangerous for any vessel of so small a size to put to sea."
The courage of the undertaking and the unexpected efficiency of the propeller, rendered the little vessel during this voyage an object of much interest; and her progress was watched with solicitude from the cliffs by nautical and naval men, who were loud in their praises. These favorable impressions reached the Admiralty and produced a visible effect there. In March, 1838, the Lords of the Admiralty requested Mr. Smith to have the vessel tried under their inspection. Two trials were accordingly made, which were considered satisfactory; and thenceforth the adoption of the propeller for the naval service was deemed a not improbable contingency.
Before finally deciding, however, upon the adoption of the propeller, the Lords of the Admiralty considered it desirable that an experiment should be made with a vessel of at least 200 tons; and Mr. Smith and the gentlemen associated with him in the enterprise, accordingly resolved to build the Archimedes. This vessel, of 237 tons, designed by Mr. Pasco, laid down in the spring of 1838, was launched on the eighteenth of October following, and made her first trip in 1839. She was fitted with a screw of one convolution which was set in the deadwood, and was propelled by two engines [4] of the collective power of eighty horses. Her cost was 10,500 pounds. She was built under the persuasion that her performance would be considered satisfactory if a speed was attained of four or five knots an hour; and that in such an event, the invention would be immediately adopted for the Navy. Nearly twice this speed was actually obtained. After having made various trials on the Thames and at Sheerness, the Archimedes on May 15, 1839 proceeded to sea. She made the trip from Gravesend to Portsmouth, under adverse circumstances of wind and water, in twenty hours. At Portsmouth she was tried against the Vulcan, (paddle wheels), one of the swiftest vessels in Her Majesty's service. The trial took place before Captain Crispin, Admiral Fleming, and other competent authorities who acquired from the result a very high opinion of the efficiency of the screw as a propeller, and this opinion they expressed in writing to Mr. Smith. These successes were achieved by a screw of one complete convolution. . . .
Because of an accident to her boilers the Archimedes soon had to be returned to London for new boilers. Repairs consumed five months, at the end of which time, upon the request of the Dutch government, the Archimedes was ordered to Texel. On the way a crankshaft broke, necessitating a return to England. In the course of the repair work then taken in hand "the form of her screw was altered, by dividing the one whole turn into two half turns, which, being placed on the opposite sides of the axis, gave to the propeller the character of a double-threaded screw of half a turn."
Further tests were made in 1840 in the course of which the Archimedes circumnavigated Great Britain, being shown in the important ports, and then made a voyage to Oporto in sixty-eight and one-half hours. Later she visited Antwerp, Amsterdam, and other places on the continent.
In 1840 and 1841 the first screw-propelled merchant vessels using the Smith system were built. The Princess Royal at Newcastle, the Margaret and the Senator at Hull, and the Great Northern (1,500 tons) at Londonderry.
In 1841 the Rattler (880 tons), first screw-propelled vessel of the British Navy, was laid down. In 1843, 1844, and 1845 extensive trials were carried out with the Rattler in the course of which different forms of propeller were tried, one with the length of the screw equal to about one-sixth convolution being found to give the best results. These experiments thus led to the modern form of screw propeller.
The performance of the vessel, the Rattler, was found to be so satisfactory that the Lords of the Admiralty ordered twenty vessels to be fitted with the screw under Mr. Smith's superintendence. The screws introduced into these vessels were in every case double threaded screws, set in the deadwood, after the fashion adopted in the Archimedes and the Rattler; and the whole of the screw vessels built in this country have been constructed upon this original type.
John Ericsson and the Screw Propeller
John Ericsson was born in the province of Vermland in Sweden, July 31, 1803. His father was a mine proprietor, and at the age of seven his mechanical mind was so far developed that he produced original combinations. At ten years of age he already had made mechanical drawings to his own design and models with* his own hands. This attracted the attention of the celebrated Count Platen, to whose talents and energy, Sweden is indebted for her magnificient Canai of Gotha— by far the greatest engineering work of the North of Europe, 300 miles long. By the influence of Count Platen, Ericsson was made a cadet in the corps of Mechanical Engineers, and was employed by the Count Platen as leveller and draughtsman on the great ship canal, where he soon gave evidence of his remarkable talents.
In 1826 he constructed an air engine, which was worked with the pine fuel which abounded in Sweden and with which the engine gave good results. But considering that England was the proper field for the development of such an invention, he came here [Note: The United States. Ed.] on May 18 in that year to push his fortune. With the coal fuel used in England, however, the air engine was not found to work well; and Ericsson accordingly now found himself alone in a strange country with an unserviceable invention as his only dependence. His energies, however, were stimulated by difficulty. His brain was his mint ...
Before taking up work on the screw propeller he developed a forced draft boiler in which rapid combustion was maintained by means of an exhaust fan; in association with John Braithwaite in seven weeks (1829) he produced a locomotive, the Novelty, which made forty miles an hour . . . "still (in 1866) remembered as a most creditable example of ingenious contrivance, and symmetrical and elegant construction"; then (about 1832) he took up the construction of fire engines.
His propeller patent was taken out in July, 1836, following which time he made experiments with a two-foot long model which was made to sail round a circular vessel of water, the small engine in the boat being driven by steam conveyed through an upright pipe, which revolved at the center of the vessel, and from whence a tubular arm extended to the engine. The results attained in this way were considered satisfactory, and in 1837 a vessel 45 feet in length, 8-feet beam, and 3-feet draught of water, was built on the Thames, in order to test on a larger scale the merits of the invention. This vessel, which was called the Francis B. Ogden, was launched on April 19, 1837, and was tried on April 30 in the same year. Her success was remarkable. She at once attained a speed of ten miles an hour. A schooner of 140 tons was towed by her at the rate of seven miles an hour, and the American packet ship Toronto was towed at the rate of four and one-half miles an hour. These experiments were many times repeated with similar success, and during the summer of the year, Captain Ericsson invited the Lords of the Admiralty to inspect the performance of his little vessel. Accordingly, Sir Charles Adam, then Senior Lord of the Admiralty, Sir William Symonds, then surveyor of the navy, Sir Edward Parry, Admiral Beaufort, and other gentlemen of scientific and naval distinction, embarked at Somerset House on board the Admiralty barge, which was then taken in tow by the Francis B. Ogden, and the screw vessel with the barge in tow proceeded under steam to Limehouse and back, at a speed of about ten miles an hour.
It may well be noted at this point that Captain Ericsson in this demonstration before the Lords of the Admiralty preceded Mr. Smith by three or four months. The account continues:
Notwithstanding this favorable experiment, Captain Ericsson, from some inscrutable reason, received no encouragement from the Admiralty; and he says that he at length discovered the impediment to lie in an idea taken up by the surveyor of the navy that as the propelling power was applied at the stern, the vessel could not be steered in an efficient manner. It is well known that in the case of paddle vessels which have been lengthened considerably by the bow, it is afterwards difficult to keep them head to the wind, from the propensity they acquire to turn round like a weather-cock, being brought so far astern; and the surveyor of the navy probably thought that in the case of a screw vessel with the propelling instrument at the very stem, this fault would be aggravated in a serious degree. Such a presumption was certainly a natural one at the time; nevertheless it is clear that it was still only a presumption, and the question was one to be settled, not by instinct, but by experiment. If any objection of the kind existed it ought to have been stated in a candid manner; but this was not done, and Ericsson appears to have left this country in disgust, carrying his invention to America. The objection alleged to have been raised by the Admiralty authorities against Ericsson's plan, they could not raise against Smith's; for, before Smith put himself in communication with them, he had proved, by numerous conclusive trials, that his vessel would steer when going head to wind, and any hypothetical objection became untenable when it was confuted by facts which were well established and widely known.
Thus while England lost, America gained, the knowledge, experience, and ability of John Ericsson for the development of screw propulsion; and these circumstances forced parallel developments of the screw propeller in the two countries. Thus also, John Ericsson was forced to go to the country, where, more than twenty years later, his Monitor played the leading part in a dramatic and crucial battle in the history of United States, if not of the world. Certainly the battle of the Monitor and Merrimac sounded the death knell of the then old type of war ship.
In the winter of 1837, a canal boat, called the Novelty, was fitted with Ericsson's propellers and was set to ply on the canal between Manchester and London. The propellers were only two feet six inches in diameter, and they were driven by an engine of only ten horsepower; nevertheless the boat realized a speed of eight or nine miles an hour. This is the first example of a screw boat being employed for commercial purposes; but this boat was in a short time laid up owing to the failure of her owners.
At this juncture, Ericsson came into communication with an officer of the United States Navy, Captain Robert F. Stockton, a man of talent, energy, and means. Captain Stockton was so much pleased with the performance of Ericsson's experimental boat, that he ordered an iron vessel seventy feet long, ten feet beam and fifty horsepower, to be constructed and fitted with the new propeller. This vessel, which was called the Robert F. Stockton, was launched at Liverpool in the month of July, 1838, and her first trial took place in the following September. The engines were direct-acting, connected immediately to the propeller.
Later in 1838 and early in 1839 trials of the Robert F. Stockton were held in the Thames. "In April, 1839, the Stockton left England under the command of Captain Crane, and proceeded under sail to America. In the latter part of 1839, Captain Ericsson proceeded to America, where he has remained ever since."
Ericsson used, in his earlier experiments, and his patent covered the use of, two tandem contrary turning propellers, hollow shafting being used, each propeller built up of eight blades (short axially and about one-third diameter radially) attached at their inner and outer edges to rings, the inner ring being supported from the hubs by a spider the arms of which were much like a modern three-bladed propeller. Thus the Ericsson propeller was practically three bladed from the center outward for about two-thirds of the radius and eight bladed for the remaining third of the radius and except for the supporting members necessary to this arrangement of blades, was much like a modern propeller in its proportions.
In pointing out an early modification of Edicsson's arrangement John Bourne states: "But in one of the trials at which Smith happened to be present, he suggested to Ericsson that he would probably obtain a better performance if he removed one of the wheels. This accordingly was tried, and Smith's anticipation turned out to be correct. The Robert F. Stockton was so constructed as to be able to use one wheel or two, as might appear advisable; but Ericsson's general practice since this time has been to use only one wheel."
Upon returning to the United States, Captain Stockton was successful in interesting the U. S. Navy Department in screw propulsion. In 1842 and 1843 the U.S.S. Princeton, first screw-propelled ship of the U. S. Navy was built under the supervision of John Ericsson. The engines, as well as the propeller, were designed by him and so arranged as to be beneath the water line and therefore more out of the reach of gunfire. In this feature these engines were the first of their kind, and this example in engine design was soon followed by the French in the 44-gun frigate Pomone and by the British in the frigate Amphion.
The Princeton later made a visit to Europe where she was inspected by representatives of all the leading nations. The design of her engines and armament was so impressive, and her performance was so successful, that interest in such design was greatly stimulated.
Knowing the rewards which now accrue to inventors of a new toy or a dress fastener, it may be of interest to know how the two men who "put over" the screw propeller fared in this respect.
It has been mentioned that Mr. Smith's services were retained by the British Admiralty in connection with the twenty screw propeller installations which were ordered for the British Navy. John Bourne states:
Mr. Smith, after this initiation had been achieved, retired from the service of the Admiralty, and for some years associated with Mr. Penn, after which he resided for a time in Jersey, and was finally appointed at the instance of Mr. Woodcroft, himself, a screw patentee, to the office of curator of the Museum of Patents at Kensington [Note: now the Science Mueum. Ed.] , which office Mr. Smith still (1866) fills, to the great advantage of the museum and the great satisfaction of the community. Most inadequately, however, up to the present time have his services to the public been requited; and so far his career offers little inducement to others. . . .
Francis Pettit Smith was a farmer whose idea of screw propulsion was apparently an "only child" and when this idea had been "brought up" history records no others. As stated above his invention served to bring him temporary employment and public notice and no other rewards worth mentioning.
John Ericsson, on the other hand, was an engineer, without peer in his time, so absorbed in his engineering studies that he spent twelve to fourteen hours a day, up to the time of his death in 1889, working on the many problems which attracted his attention. As in the case of Smith, the development of the propeller brought few direct rewards to Ericsson. But his propeller, coupled with his other inventions and his outstanding engineering ability, brought him into associations which assured him an income, certainly modest considering his achievements, but which made it possible for him to continue to the end with his work.