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 Chapter V, had been so successful that her owners felt justified not only in ordering another vessel but in determining that their new steamer should be the largest afloat and illustrate the latest theories of construction. There were already rumours of competition in the North Atlantic trade, and the Great Western directors did not intend to be forestalled. They decided to build an iron ship and it was accordingly announced that the _Great Western_ was to be followed by the _Great Britain_, of iron. This project was roundly condemned by the public. The fact that iron steamers were already in existence on Irish waters did not count for much. These might be good enough for Irish lakes and rivers but would be unfit for the Atlantic Ocean. The _Garry Owen_ was already forgotten. The Great Western Company, however, persisted. The _Great Britain_ was designed by the younger Brunel and launched in 1843. Her length of keel was 289 feet, and length from figure-head to taffrail 320 feet. Her beam was 51 feet. The total depth from the under side of the upper deck to the keel was 31 feet 4 inches. Her tonnage was 3500 tons and her displacement at 16 feet was 2000 tons. Her cargo capacity was 1200 tons measurement, and her coal bunkers held 1000 tons. Since no shipbuilder had the necessary data for the construction of such a vessel, and shipbuilders as a whole were by no means favourably disposed towards iron ships, possibly because they had not the plant necessary for their construction, and as there was also a very widespread belief that a vessel of the size and dimensions of the _Great Britain_ could not be built of iron, the directors were unable to find a contractor who would undertake her construction. They were therefore obliged to instal the plant for building the ship and the engines also. She was built under the supervision of Paterson of Bristol, who was responsible for the _Great Western_. It was at first intended that the _Great Britain_ should be a paddle-steamer and her lines followed in several respects those of the best paddle-steamers of the day; though the _Great Britain_ herself contained so many novel features and was of so experimental a character that it could hardly be said that she followed anything. Little had been done to demonstrate the power of the screw propeller, which for some unfathomable reason was considered to be suitable only for small vessels. However, after the construction of the _Great Britain_ had been commenced, the steamer _Archimedes_, fitted with Smith’s screw propeller, arrived at Bristol during her tour of the ports and demonstrated once and for all that the screw propeller could be used in seagoing vessels, and that, provided engines of sufficient power were installed, the screw propeller was more suitable for large hulls built to make ocean voyages than the best paddle-wheels then designed. But many years were to elapse before the shipping industry generally accepted this view. The advantages of the screw, as proved by the _Archimedes_, were not, however, lost upon the enterprising directors of the Great Western Steamship Company, and they did not hesitate to order the designs of the _Great Britain_ to be altered so that she could be fitted with a screw instead of paddles. She was not built on a slip whence she might have been launched into the river, but in an excavated dock, and when she was afloat in the dock it was found that she was too big to be got out of it. That is to say, that having been fitted with her engines while still in dock, their weight immersed her to such an extent that she could not float out. This was owing to the dock officials’ delay in finishing alterations to the dock entrance, and not to any mistake or negligence on the part of the steamer officials. She was water-borne on July 19, 1843, and was christened by Prince Albert. The floating was attended by vexatious mishaps. The _Great Britain_ was attached by a hawser to the tug _Avon_, which was outside the dock, but at the critical moment the hawser broke. The bottle of wine thrown at the ship by the Prince fell several feet short. He threw another bottle of champagne, which struck the bows, and the wine and broken glass fell upon the men below, who were pushing against her sides to keep her off the dock walls. [Illustration: MODEL OF THE “GREAT BRITAIN.”] Her figure-head consisted of the royal arms, flanked with a beehive, two cog-wheels, a dove, square, and the caduceus of Mercury in bronze on a white ground, with a scroll above and below. Her anchor was on Porter’s newly invented patent, which had been satisfactorily tested in the Navy for three years. Her designer and builder took no chances. She was put together as strongly as possible, and it was well that this was so, for in her eventful career she was altered so frequently and so much that had she not been excellently put together she would very soon have succumbed to ship surgery. Her keel was formed of iron plates varying from three-quarters of an inch thick in the middle to one inch at the ends. The plates of the hull under water were from three-eighths to half an inch at the top, except the upper plate, which was five-eighths of an inch. She was clincker-built and double riveted throughout. Towards the bow and stern and in the upper strakes the thicknesses were reduced gradually to seven-sixteenths. The ribs were of angle iron six inches by three and a half, by half an inch thick at the bottom of the vessel and seven-sixteenths thick at the top. The boiler platform was of plate iron supported upon ten iron keelsons. The hull was divided into five compartments by water-tight iron bulkheads. The decks were of wood and consisted of the cargo deck, two cabin decks, and the upper deck. The beams for the support of the decks were bars of angle iron about three inches across with an additional bar measuring five inches by half an inch riveted on the side. The beams were from 2 feet 4 inches to 3 feet apart. There were also between the angle-iron bars and deck planks a series of diagonal flat tension bars, forming a continuous horizontal truss from end to end in each principal deck; these bars were riveted to the angle irons at the crossings and at the ends in order to prevent horizontal straining. The engine-room was strengthened by adding nine additional double ribs and sixteen additional reverse ribs riveted to the original framing. Her three boilers were each 33 feet in length, 10 feet wide, and 24 feet high; she had 24 fires, 12 fore and 12 aft, with a total surface of fire-box of 288 superficial feet. Her chimney was 8 feet in diameter and about 45 feet high; her four cylinders were 7 feet 4 inches diameter with a piston-stroke of 6 feet. Her two condensers of wrought iron three-quarters of an inch thick were 12 feet in length. The main wrought-iron shaft measured 15 feet 9 inches. The engines were after Sir Mark Brunel’s patent in the position of the cylinders, except that they were disposed at an angle of about 60 degrees. The pitch of the screw was 13 feet 2 inches and its diameter 15 feet. It was six-bladed, and the screw shaft was revolved by four endless chains. The crew numbered one hundred and thirty all told and she could accommodate three hundred and sixty passengers. Her principal promenade saloon was 110 feet in length by 48 feet at the widest part and 7 feet high, and had two staircases at each end. Her first-class dining-room was 100 feet in length by 50 feet wide and 8 feet high, with staircases communicating with those of the promenade saloon. Seeing how far she excelled all other steam-ships, she well merited being called by the newspapers a “stupendous steam-ship” of “unparalleled vastness.” [Illustration: MODEL OF ENGINES OF THE “GREAT BRITAIN.”] Her rig was as unique as her hull. She had six masts, of which only the second carried square sails, all the others being fore and aft rigged, and her one funnel was placed between the second and third masts. Five of her masts were stepped on turntables on deck so that they could be lowered and offer less resistance when going against a head wind. The lines of the ship were very fine, especially about the entrance from the forefoot. There was little of the “cod’s head and mackerel tail” style of build about her. She was admitted to be rather full amidships, for the accommodation of the engine, but was thought to approach as near the figure of least resistance as possible. The hull had a slight sheer and the vessel realised the expectation that she would be what sailors call “a dry ship.” After getting out of the dock at last she left for London, where she arrived in January 1845 after a stormy voyage which tested her thoroughly. She remained five months at Blackwall, being visited by the Queen and Prince Albert, and left in June of that year with about eighty passengers for Liverpool, calling at a number of ports _en route_. She left the Mersey for New York on July 26 with from forty-five to sixty passengers (accounts differ) and about 600 tons of cargo. The voyage lasted 14 days 21 hours, and her average speed was nine and a half knots, but the engines were only worked at about 600 horse-power. New York was disappointed with her, as her six low masts contrasted unfavourably with the tall graceful masts of the American ships. She made the return journey in a day less. On a subsequent voyage she broke one of the blades of her propeller, but as she made between ten and eleven knots, using both propeller and sail, it was decided when she was docked for repairs that her new propeller should have four blades only. In September 1846 she ran on the rocks in Dundrum Bay on the coast of Ireland, and was not refloated until August 1847. Thanks to her strong construction she was able to withstand a winter’s storms and a stranding of eleven months. After being brought to Liverpool, she lay for some time at the North Docks and, as the Great Western Steamship Company thought the repairs would be too costly, she was purchased by Messrs. Gibbs, Bright and Co., formerly agents for the company, and they decided to refit her. The rolling plates attached to the sides of the hull were removed. An oak keel was bolted through upon the iron plates which had done duty for a keel when she was first built, to prevent rolling. Her bottom for about 150 feet had to be entirely renewed. The bows and stern were strengthened by double angle-iron framing secured by three tiers of iron stringers 2 feet 3 inches wide and five-eighths of an inch thick. Ten new keelsons were placed in the ship running her entire length, half as deep again as those formerly used. The various alterations resulted in the cargo capacity being increased by about 1000 tons, partly through the space saved by new boilers and partly through the construction of a deck-house 300 feet long and 7 feet 6 inches high. New bulwarks were erected higher than the previous ones. The number of masts was now reduced to four.[86] Two of the lower masts were iron cylinders and the two centre masts were ship-rigged, carrying royals. The fore and jigger were fore and aft rigged, but whereas the topsail of the foremast was shaped like a lugsail that of the jigger was carried on a gaff, according to a contemporary picture. The old engines were of 1000 nominal horse-power, but it is a question if they ever worked over 600 horse-power; the new engines were nominally 500 horse-power. Her new pair of oscillating engines were by John Penn and Son, engineers, Greenwich, and had cylinders 82¹⁄₂ inches diameter and 6 feet stroke. By the use of cog-wheels the screw shaft made three revolutions to one of the engine. [86] According to a description and picture in the _Illustrated London News_ she had five masts, the first, fourth, and fifth masts being fore and aft rigged, but the fifth mast is probably an incorrect addition to the picture. If she had five masts the number must soon have been reduced. The screw was three-bladed, 15 feet 6 inches diameter, and 19 feet pitch. There were six boilers, and her bunkers held 700 tons, and other accommodation enabled her to stow 510 tons more. To lessen the vibration experienced from the screw and machinery, eight new wrought-iron beams were placed transversely through the vessel, locking her sides together. The bases on which the machinery rested were made stronger, and she was further strengthened by massive iron entablature beams to the engines, buttressed by a framing of teak wood, each piece being 20 inches wide and 3 feet deep, running on either side of the engines transversely and diagonally to the sides of the ship. This solid timber extended 17 feet 6 inches on each side of the engine. The whole of this framing was bolted together and to the sides of the ship by wrought-iron bolts. The new arrangement of the boilers gave her a lessened coal consumption. Little more need be said about this steamer. She made one voyage afterwards to New York and back, and being then acquired by Messrs. Antony Gibbs and Sons was placed in the Australian trade at the time of the gold fever, and continued a regular voyage between England and Australia for many years. She was afterwards patched up afresh and had her engines removed, but was then such a failure that though she got as far as the Falkland Islands, leaking badly, she was abandoned to the underwriters, and is now ingloriously ending her days as a coal hulk.