Chapter XII

. hereafter;[81] but the propeller seems to have been very primitive. The screw propeller was also proposed in 1752 by the mathematician Daniel Bernoulli. A patent was granted in 1794 to William Lyttleton for a screw propeller which was caused to revolve by an endless rope passing round a wheel at the end of the axle. It was a distinct attempt to solve the problem and nearly succeeded, but it failed because there was too much of it. Had he been contented to use one pair of blades he would have obtained better results than by using two pairs of wide blades and two odd blades, arranged with three blades on either side of the axle so that his propeller became really a long spiral wheel. He also failed from the lack of sufficient power to drive the wheel, as manual labour only was used. Still, a boat fitted with this screw was tried at the Greenwich Dock, London, and a speed of two miles an hour was stated to have been obtained.

[81] See p. 376.

In 1800 Mr. Shorter, master of the transport _Doncaster_, brought out two plans of propulsion. One was in the form of two duck-foot paddles with an alternate movement; the other was a two-bladed screw propeller. The latter was attached to an inclined shaft carried by a universal joint to the deck of the vessel. One of these methods was said to have moved the _Doncaster_ at a speed of about a mile and a half an hour, the contrivance being driven by eight men running round a capstan. It is difficult to believe from the picture which accompanies his plan, dated 1800, that a transport of the size depicted could have been moved at half that speed with the apparatus shown, although the fact that it was mechanically propelled is attested by credible witnesses.

The first really successful screw-propelled boats were those of Colonel John Stevens, which were in operation on the Hudson River from the years 1802 to 1806, and were the first to be used for the effective navigation of the waters of any country. References have already been made to Stevens’ experiment with paddle propulsion in 1796. When he, Chancellor Livingston, Nicholas J. Roosevelt, and Isambard Brunel were making experiments in steam propulsion on the Passaic River, New Jersey, they tried a horizontal centrifugal wheel in a boat of 30 tons, drawing water from the bottom of the boat and discharging it at the stern. This is in its general principles similar to the plan that Mr. Ruthven tried in England on the _Waterwitch_ more than half a century afterwards. They also, unsuccessfully, attempted to use elliptical paddle-wheels.

Probably the best description of Colonel Stevens’ propeller is that which he himself contributed to the _Medical and Philosophical Journal_ of New York in January 1812. He refers to the “mischievous effects necessarily resulting from the alternating stroke of the engine of the ordinary construction” which induced him to turn his attention to the rotary principle of steam-engine construction. “For simplicity, lightness, and compactness the engine far exceeded any I have yet seen. A cylinder of brass, about eight inches in diameter and four inches long, was placed horizontally on the bottom of the boat: and by the alternate pressure of the steam on two sliding wings, an axis passing through its centre was made to revolve. On one end of this axis, which passed through the stern of the boat, wings like those on the arms of a windmill were fixed, adjusted to the most advantageous angle for operating on the water. This constituted the whole of the machinery. Working with the elasticity of the steam merely, no condenser, no air-pump was necessary; and as there were no valves, no apparatus was required for opening and shutting them. This simple little steam-engine was, in the summer of 1802, placed on board a flat-bottomed boat I had built for the purpose. This boat was 25 feet long, and about 5 or 6 feet wide. She was occasionally kept going until the cold weather stopped us. When the engine was in the best order, her velocity was about four miles an hour. I found it, however, impracticable, on so contracted a scale, to preserve due tightness in the packing of the wings in the cylinder for any length of time. This defect determined me to revert again to the reciprocating engine.”

[Illustration: STEVENS’ 1804 ENGINE, FITTED INTO OPEN BOAT WITH TWIN-SCREW PROPELLERS.]

Stevens and his son were crossing the Hudson in this boat on one occasion when the boiler, which was constructed of small tubes, gave way, and the next boiler was constructed with the tubes placed vertically. The engine was kept going for a fortnight or three weeks in the latter part of the summer of 1804, the boat making excursions for two or three miles up and down the river, and for a short distance he could get a speed out of it of seven or eight miles an hour.

Stevens’ early experiments with the screw propeller taught him that a vessel driven by only one screw has a tendency to move in a circle. This tendency is displayed in single-screw vessels to the present day. As is well known, a vessel driven by a right-handed screw will deflect slightly to the left, and a vessel driven by a left-handed screw will have a tendency to turn to the right. The explanation given of this peculiarity in the Stevens’ boat by Dr. P. Jones, who was superintendent of the United States Patent Office up to the date of its reorganisation under the law of 1836, in the _Journal of the Franklin Institute_ for 1838, is that this tendency was due to the lessened resistance, as the vanes of the propeller rose towards the surface, in consequence of the greater ease with which the water was removed out of the way. Consequently Stevens overcame this difficulty by using two such wheels placed side by side and revolving in reverse directions.

The original screw-engine is still in existence in the Museum of the Stevens Institute at Hoboken, New Jersey. The original boat, of course, has long since disappeared. A replica of it was tried with the old engine on the Hudson in October 1844, and attained a speed of eight miles an hour.

One great difficulty which early steamers had to contend with was that of boiler pressure. It should be remembered that the five distinct means Stevens proposed in connection with his screw propeller were:

1. The short four-bladed screw propeller.

2. The use of steam of high pressure.

3. The multitubular boiler.

4. The quick-moving engine connected directly to the propeller shaft.

5. Twin screws.

Not one of these means was applied to steam-ships until about forty years later, but all have contributed since their adoption to the success of the ocean navigation of the present day.

Stevens’ plan for working twin screws by a single cylinder is the most simple that could be devised. When the screw propeller came into use this plan was revived both in America and in Europe, and was known in France as the “Etoile” engine.

The principal reason for Stevens’ failure with the screw propeller was that there were no tools or competent workmen in America to construct properly the steam-engines that he planned between 1800 and 1806, and success was therefore impossible. He therefore reverted to the paddle-wheel with its slow-moving engine and the boilers then in use, carrying steam at a pressure of two or three pounds above the atmosphere. Stevens was not disposed to abandon the screw entirely, for he presented a plan in 1816 to the United States Government for a warship propelled by that means, but nothing came of it.

In the spring of 1825 an advertisement appeared in the _Times_ offering a hundred guineas for a means of propelling vessels without paddles, and in that year a company was formed for applying the gas vacuum engine to canal navigation.

[Illustration: THE “Q.E.D.”]

Some of the earlier steam-engine-propelled iron vessels were strange craft. Designers and builders felt that they were entering upon new ground, and being less trammelled by tradition allowed their fancy free play. Their plans were occasionally daring in their originality and came astonishingly near to achieving success.

A freakish-looking vessel was launched on July 15, 1844, from the yard of her owner and builder, Mr. Cootes, at Walker-on-Tyne. She was a collier, built of iron, and carried a screw propeller driven by a small engine. On this account she is said to have been the first iron screw collier, antedating by some years the _John Bowes_, to which the honour is usually given. This ship was confessedly an experiment and was named the _Q.E.D._, and as her name was not changed during her career she no doubt gave satisfaction. The sea-borne coal trade was largely confined to wooden brigs of comparatively small tonnage. The _Q.E.D._ was barque-rigged, “with taut masts and square yards, the masts raking aft in a manner that is seldom seen except in the waters of the United States. She was provided with a 20-horse-power engine by Hawthorn, which turned a propeller (screw), a compound of several inventions, having four flies or flaps at right angles with each other, the bend of each flap at an angle of 45 degrees from the centre.”

On her first voyage to London,[82] when she had about twenty keels of coal on board, she grounded on the Gunfleet Sands, but was refloated undamaged after some of her cargo had been thrown overboard.

[82] Mr. Charles Mitchell, afterwards head of the shipbuilding firm which amalgamated with Sir W. G. Armstrong and Co. under the style of Armstrong, Mitchell and Co., Ltd., went to sea in this vessel for one or two voyages, to watch the behaviour of her engines.--“The Making of the River Tyne,” by L. W. Johnson.

Constructionally she presented several very novel features, which embodied the iron shipbuilding science of the time. Her over-all length was 150 feet, beam 27 feet 6 inches, and with the 340 tons of coal on board she was constructed to carry, she drew 11 feet 9 inches aft and 10 feet 3 inches forward. She is said to have been the first water-ballast vessel, for her hold was divided into separate chambers and each chamber had a false floor, between which and the hull was the space for water-ballast. The water, which was her only ballast, was admitted through taps and was pumped out by her engine. This was just a small steam auxiliary, capable of giving her a speed of four knots in a calm. Her mizzen-mast was of iron and hollow and was used as a funnel for the engine fires, so that when her furnace was going her mizzen rigging appeared to be on fire. Her bows had a sharp wedge-shape with considerable sheer, her stern overhung to an unusual degree, and her counters were very flat so as to lift her stern to the sea. The stern bore an armorial bearing with the motto “Spes mea Christus,” and “_Q.E.D_ of Newcastle.” The cabin was commodious, with a raised roof surrounded with window lights, and had four sleeping compartments, with a stateroom for the captain. A swinging compass was suspended, having a magnet on each side, and one before it, to counteract the attraction of the iron. Her shrouds were of wire rope served over with a strong double screw to each, a method in use to the present time. The main-mast from step to cap was 65 feet, the main yard 52 feet, and the mast, from the keel to the royal truck, was 130 feet.

As she steered with ease, sailed well, and exceeded expectations with the screw propeller, confidence was expressed “that the time is not far distant when our ships of the line will be fitted with engines and screws in a somewhat similar manner.” Four years after her launch her engines were removed and she was rigged as a barquentine. She ultimately went to the bottom of the English Channel in 1856.

As a steam collier the _Q.E.D._ can scarcely have been a success or her engines would not have been taken out of her. Probably the first real steamer to which the title can be applied was the _John Bowes_, built at Messrs. Palmer’s yard, formerly in the possession of Mr. Cootes. Messrs. Palmer Brothers and Co. established the fifth yard on the Tyne for iron shipbuilding purposes and the _John Bowes_ was their first vessel. Two steam colliers of a sort had already been built on the Mersey, but they were little better than steam barges. This, the first seagoing steam collier with a screw propeller, was 167 feet over all, 25 feet 7 inches beam, 15 feet 6 inches depth, and of 270 tons register. The firm started in 1851, and about this period the working of the new Midland coalfields began seriously to affect the sale of north country coal, which had hitherto been conveyed to London in small collier brigs. It now became imperative in the interests of colliery owners to devise some means by which the staple produce of the district could be conveyed to the metropolis expeditiously and regularly. Sir (then Mr.) Charles Palmer, who was connected with several large collieries in Northumberland and Durham, therefore designed the _John Bowes_ with a carrying capacity of 650 tons, and capable of steaming nine miles an hour. She was launched on June 30, 1852. The experiment proved a complete success, and to it may be attributed the important development of iron shipbuilding on the north-east coast which afterwards took place. The _John Bowes_ was the forerunner of a long list of screw colliers, and was speedily followed by the _William Hutt_, the _Countess of Strathmore_, and numerous vessels of a similar type.

Captain Blackett, R.N., speaking at the launch of the _John Bowes_, expressed the opinion that paddle-wheel ships were doomed altogether. The chairman, Mr. Charles M. Palmer, referred to the superiority of the vessel over the sailing brigs, and added: “The application of iron to shipbuilding, especially to colliers, gives great advantages. There being much more space than is required for cargo, the surplus in the _John Bowes_ is available for water-ballast, by placing an inner bottom, with compartments, thus saving much detention and expense, the water being pumped out by the engine used for the screw propeller. When this description of collier is brought into general use, and the coal merchants can be supplied with regularity, and, moreover, cannot take advantage of the fleets, they will no doubt purchase from the coalowners at a price on board in the north, and thus obviate the ruinous speculations now existing, and present the most effectual mode of regulating the trade. I am aware that in substituting iron screw steamers for wooden sailing vessels we are running counter to the wishes of many shipowners, but I am satisfied we are taking the right course; we have the public with us: and I am confident of success.” His confidence is justified by the history of the Tyne.

[Illustration: THE “JOHN BOWES.” LAUNCHED 1852.]

[Illustration: THE “JOHN BOWES,” 1906

(PASSING PALMER’S SHIPYARD, WHERE SHE WAS LAUNCHED, 1852.)]

Numerous attempts were made to solve the problem of the proper application of the screw propeller. Most of them were fantastic and a few were even absurd. The difficulties that inventors had to surmount were so great that it is no wonder many gave up the struggle in despair, notwithstanding the obvious advantages of this method. They had to decide where the propeller should be placed so as to give the best results, without interfering with the steering powers of the rudder. They had to ascertain the best material for the bearings of the propeller shaft in order to avoid the wearing away or the overheating of the shaft and bearings through the friction caused by its revolutions; for worn bearings meant leakage and excessive vibration, and the latter meant an ever-increasing strain on the structure of the ship, this being particularly the case with wooden vessels.

By degrees these obstacles were overcome, but the questions of the number, size, and shape of the blades, their pitch, or theoretical forward movement in making a complete turn, their degree of immersion and their most efficacious speed, are taxing the brains of the most skilled naval engineers and architects of the present day. Obviously, these questions are of the highest importance to all students of marine engineering no less than to steam-ship owners. As the power of the engines increased other considerations had to receive attention, including the best material for the construction of the propeller and the best methods of building or casting it to stand the enormous strains imposed upon it by the work it had to perform.

Almost simultaneously John Ericsson, the famous Swedish inventor, and Francis Pettit Smith, a Middlesex farmer, were engaged in experiments. Mr. (afterwards Sir) F. P. Smith made, in 1836, a clockwork model of a boat with a screw propeller, and it was so successful that he built a steam launch in order to try the experiment on a larger scale. This boat, the _F. P. Smith_, was about 29 feet long and 5 feet 9 inches beam, and was tried in the Paddington Canal in 1837; its power was derived from a steam-engine with a cylinder having a diameter of 6 inches and a stroke of 15 inches. The propeller was of wood with two full turns, and was placed some distance in front of the sternpost, where it was driven by a system of bevel wheels from the engine to the shaft. The propeller lost a blade on one of its trips, thereby adding to the speed of the vessel, and this led Mr. Smith to instal another screw with one turn only, or a half-turn on each blade. A metal propeller was afterwards substituted, and the boat went from London to Folkestone and other places on the coast at an average speed of five to five and a half knots.

It is stated Mr. Smith built a vessel of 60 tons[83] which, with a screw propeller, attained a speed of seven or eight miles an hour and went from Blackwall to Margate in eight and a half hours, and that she also towed the _British Queen_ steamer into the West India Dock. This probably refers to the _F. P. Smith_, the assertion that she was of 60 tons being erroneous. The results of the experiment were so satisfactory that a syndicate was formed which took the matter up and brought out the Ship Propeller Company, to whose capital Messrs. Rennie, the shipbuilders, subscribed £2000.

[83] _Historic Times_, March 1849.

This syndicate built the steam-ship _Archimedes_, the first seagoing vessel driven by a screw propeller. She was of 232 tons, and had engines of 80 horse-power. The cylinders were 37 inches in diameter and of 3 feet stroke, and the screw, being geared in the proportion of a fraction over five to one, made 140 revolutions per minute to about 27 revolutions of the engine shaft. The screw was formed of plates of iron fastened to arms of wrought iron, keyed upon a wrought-iron shaft. The boiler was suited to the shape of the vessel. The engines, chimney, boiler, coal-boxes, driving machinery, and propeller weighed altogether rather more than 64 tons. The propeller was fitted in such a way that it could be brought on deck for repair or when not required for use. The ship was 125 feet over all and 22¹⁄₂ feet beam. Various types of propeller blades were tried with her, and she was also sent on a voyage round the ports of Great Britain to demonstrate the effectiveness of this method of propulsion. On this trip she called at Bristol, where the _Great Britain_ was under construction, and was thus the cause of the screw propeller being adopted for that ship.

One of the tests to which the _Archimedes_ was subjected was a voyage between Dover and Calais in the company of two of the Post Office packets, which she beat handsomely. She went from London to Portsmouth in 1839, and continuing her voyage round the ports of the British Islands, to provide ocular proof to all interested, put in at Plymouth, where she was boarded by Admiral Sir Grayham Moore and the Commander-in-Chief, who were then convinced of the usefulness of the screw.

The next year the _Novelty_ was built for the owners of the _Archimedes_ by Mr. Wimshurst at Blackwall, to demonstrate still further the seagoing merits of a screw-propelled vessel. Her two-bladed screw was placed as near the sternpost as possible, and one of its features was that it had only a quarter of a turn to the blade. Her boilers worked at a steam pressure of sixty pounds above that of the atmosphere, the highest then attempted, and up to then regarded as impossible for a steamer. She took a general cargo to Constantinople, to which port she was the first screw cargo boat to go; but as on her return objections were raised that the pressure was too high, other engines were substituted working at only a quarter of the pressure. She was one of the few vessels in which the mast was used as a funnel, her mizzen-mast being made hollow and of iron for the purpose: she is also said to have been the first vessel to be fitted with an iron mast.

John Ericsson in 1836 patented a propeller consisting of two drums from which projected seven helical blades connected by an external hoop. The blades were inclined in opposite directions, thus forming a double screw propeller, the propellers being placed immediately behind the rudder, which had the usual “shark’s mouth” to allow of steering. The shafts were made so that one passed through the other, the outer one being tubular. The drums revolved in opposite directions, that nearer the sternpost moving at a slightly faster rate than the after drum. This method of arranging the propellers was adopted with a view to avoiding the loss caused by the motion imparted to the water by the single screw, but it was found that the trouble caused by the contrivance was not worth the results obtained. Another drawback was that the extra friction induced by one shaft operating within the other was so great that the contrivance was practically useless where a high speed was desired. The steamer _Francis B. Ogden_ was tried with this type of propeller in 1837, and towed the American sailing ship _Toronto_, of 630 tons burden, on the Thames at the rate of five miles an hour. The _Francis B. Ogden_ was about double the tonnage and power of Smith’s boat, being 45 feet long and having a high-pressure two-cylinder engine giving the propellers about 30 revolutions per minute. Ericsson’s next experiment was with the _Robert F. Stockton_, which was built by Laird at Birkenhead in 1838. She was 63 feet long and of 33 tons, and had engines of 30 horse-power. Prior to this his screw boat towed the Admiralty barge with my Lords of the Admiralty on board on the Thames, but the effort to convince them of the practicability of the method was doomed to failure, since they had previously decided that as the power was applied at the stern the vessel would not steer.

[Illustration: MODEL OF THE “NOVELTY.” BUILT 1839.]

The _Robert F. Stockton_ crossed the Atlantic under canvas in 1839, and after one of the screws had been removed as useless, she was employed for a quarter of a century as a single-screw tugboat on the Delaware, under the name of the _New Jersey_. Commodore Robert F. Stockton in that year induced Ericsson to resign his office in London as superintending engineer of the Eastern Counties Railway and go to the United States. Several vessels were fitted with his propellers for river and inland waters navigation in America.

Mr. Ogden, who was American Consul at Liverpool from 1829 to 1840, and at Bristol from 1840 to 1857, “is credited with having first applied the important principles of the expansive power of steam and with the employment of right-angular cranks in marine engines. In 1813 he received a patent for low-pressure engines with two cylinders, working expansively, and the cranks being adjusted at right angles, and in 1817 the first engine ever constructed on this principle was built by him in Leeds, Yorkshire. He submitted his plan to James Watt, at Soho, who declared at once that it was a beautiful engine and that the combination was certainly original.”[84]

[84] Appleton’s “Cyclopædia of American Biography.”

The definite adoption of the screw propeller, both for the Royal Navy and the Mercantile Marine, may be said to have taken place in 1840-41. For some years no bearings of brass or other metal could be got to stand the strain of the stern shaft, “and at one moment it seemed as if the screw must be abandoned and the paddle-wheel reverted to. Mr. Penn solved the problem by using lignum-vitæ wood bearings, which, lubricated by water, were found to act without any appreciable wear, and in this simple way the screw has already been able to reach a point of development from which we can now calmly look back upon the financial risks and terrors which beset the early days of steam navigation.”[85]

[85] _The Times._

The difficulty of steering screw-propelled vessels was considerable, principally owing to the method of placing the screw in an aperture in the deadwood, while at the same time retaining the full underbody aft. The full power of the screw could not thus be exerted, and the attendant churning of the water interfered with the steering power of the rudder. A system of double rudders was brought out in an attempt to solve the difficulty, but the disadvantages it possessed were against its general adoption. These rudders were hung respectively one on each side of the forepart of a somewhat extended sternpost, against which they lay when amidships, moving out as required to steer the ship, or both could be moved outwards to help to stop her. The sternpost was really a vertical hollow box through which the screw framing passed, the screw working behind it and beyond the rudders. Later improvements in shipbuilding rendered this device unnecessary.

The difficulty was solved by the simple expedient of placing the sternpost farther aft so as to give room for a greater space in the deadwood in which the propeller was to act.

The superiority of the screw to paddles was now being gradually admitted, and the number of small vessels fitted with screws increased. But no one had as yet dared to launch a large screw steamer for ocean voyages.

The honour of being the first to do this was gained by the Great Western Steamship Company. The _Great Western_, which has been mentioned in