Chapter IV: The Inauguration of the Liner (2)

It was in this ship that a type of engine was fitted to which, so far, we have not referred. This was the oscillating kind, and was destined to become pretty well universal in paddle-ships, though not without serious opposition at one time. This type had been patented as far back as 1827, by Joseph Maudslay, and in the _Aaron Manby_, already mentioned, the machinery was of an oscillating nature, for which Manby had obtained a patent in 1821, but even farther back still--in 1785--William Murdoch had proposed the use of oscillating cylinders. It is only fair to Maudslay to say that he had independently worked out this arrangement, and so afforded yet another instance of the possibility, which I have enunciated before, of different inventors working at the same set of problems and bringing about a similar method of solution. In the accompanying illustration is shown Maudslay’s original oscillating engine. In this type the cylinders, instead of being fixed, oscillate, and the necessity of the connecting rod is dispensed with, for the cylinder is placed immediately underneath the crank shaft, as a reference to the illustration will show. Each cylinder is mounted on trunnions in the same manner as a cannon, being placed at a point about the middle of the cylinder’s length, so that it can swing, or oscillate, in such a way as to correspond with the arc which the crank makes in its movement. Thus there are both weight and valuable space saved. In the instance before us the condenser is placed between the two cylinders; the central trunnions communicate with the condenser, and the outside trunnions with the steam pipe. But Maudslay’s engines did not at that time find the appreciation which had been hoped for, and it was not until 1838, when they were re-introduced by John Penn, that they received their full favour. We shall return to the oscillating type when we come to consider the _Great Eastern_. But we may remark that the interesting steamship illustrated opposite page 130 was also provided with the oscillating pattern. This is the packet steamer _Pacific_, which was built in 1853 for the Mediterranean service, and is another example of a vessel constructed on the wave-line system. She was built of iron, and had nine water-tight compartments.

The _Pacific_ was interesting in another feature, in that she generated her steam in four tubular boilers, each of which had five furnaces. Briefly the evolution of the boiler had been on this wise: As originally fitted in the _Clermont_ and _Comet_ it was simply a water-tank set in brickwork, and was nearly full of water, with the fire outside, or, to use the expression generally employed, “externally fired.” In those days the pressure of the steam was not greater than the pressure of the air, which we saw to be 15 lb. to the square inch. Then came a modification of this in which the furnace was placed inside the boiler, the advantage being that, with the water all round, the latter could be the more readily heated. This developed into the marine “box” boiler, with internal flat-sided flues and furnaces. This type continued to be fairly universal until about 1845, but the utmost pressure of steam which these were capable of enduring was not above 35 lb. or thereabouts. But tubes instead of the flat flues began to be introduced about the year 1850, owing to the suggestion of the Earl of Dundonald, and these were to be of about double the diameter of those which had been common to locomotives for the previous twenty years. The pressure was soon raised considerably, but there was a strong prejudice against using high pressures at sea, and the idea was not encouraged.

_From the Model in the Victoria and Albert Museum._]

_From the Model in the Victoria and Albert Museum._]

_From the Model in the Victoria and Albert Museum._]

In the same year that the _Pacific_ took the water was launched the _Himalaya_, of which a beautiful little model is here illustrated. She was built for the P. and O. Line. This fine ship-rigged steamship was constructed of iron at Blackwall in 1853, and in the following year was bought by the British Government and steamed away from Plymouth with soldiers for the Crimea. She was of 4,690 tons displacement, and in that year made a record run from Gibraltar at an average speed of 13½ knots. Originally she had been built for carrying both cargo and passengers, but now she is, or was, ending her sphere of usefulness as a coal hulk at Devonport. Her coal “endurance”--she could carry 1,200 tons--made her a valuable asset, and her six water-tight bulkheads rendered her still more efficient. As will be seen from the illustration, she had a single propeller, and this was driven by yet another type of engine, which we have now to consider. We refer to the vertical trunk engine. We shall be able to understand this better if we examine the illustration facing page 132, which reproduces a drawing of a similar type of engines installed in the P. and O. _Candia_, built a year later than the _Himalaya_. In the trunk engine the piston-rod was done away with, so that the connecting rod is attached directly to the piston within a trunk or tube. This trunk passes through a steam-tight stuffing-box in the cylinder cover, and is made wide enough to allow of the lateral vibrations of the connecting rod inside. As long as steam pressures did not exceed 35 lb. this proved to be satisfactory; but the friction of the stuffing-boxes when they became of large dimensions was a serious drawback. The _Candia_, for which these engines were made, was a screw ship, and the cylinders were placed in a fore-and-aft position. By means of this type of engine, employing trunks, the height required was greatly lessened, and it was not necessary, as will have been noticed was essential in the case of the _Great Britain’s_ engines, that part of them should come up through the deck. Thus, the trunk type meant a saving of valuable space. Between the cylinders were arranged the condensers, which were of the jet type. We may stop to remind the reader that the condenser had been the invention of Watt, who had improved on the Newcomen engine not merely by covering over the top of the cylinder, but by condensing the exhausted steam in a separate vessel, called a condenser. This condensation he brought about by means of a jet of cold water, and the same principle was still employed in the _Candia_. Condensation having taken place, the water thus formed, together with any air which has got in, is then drawn off by the air-pumps, which will be seen in the illustration to be worked from an intermediate crank. It will be remarked on glancing at the left of the picture that the _Candia’s_ crank shaft was connected with the propeller shaft by means of spur gearing, which doubled the speed of the screw, and so of the ship, but yet allowed the actual engines to run comparatively slowly. This toothed wheel idea was a better method than that employed in the _Great Britain’s_ engines, though it was only just one stage better. There was a rooted objection in the early days of the screw to running the engines at a great speed, and thus it was only by some such means of gearing that the propeller was made to revolve quickly. In the course of time, when a wider experience and knowledge of engineering matters had been obtained, the gearing was done away with and the engines became direct-acting, and so there ensued far less friction, an absence of complication, and less expense caused by gearing. At the same time the power obtained by the newer method became more direct.

A customary apparatus nowadays adopted for steamships is the surface condenser, and in the effort to increase the steam pressures this has been a potent factor. But it had already been tried by Watt, by David Napier, and re-introduced by Samuel Hall in 1831. The surface condenser consists of a number of brass tubes about three quarters of an inch in diameter, through which a stream of cold water circulates. This necessarily keeps the pipes cool, and thus condenses the exhaust steam which is thrown on to them from the cylinder; it is practically a kind of tubular boiler. Instead of the jet, as in the older form of condenser, it is the outside of the pipes which performs the office, and the air-pump does its work as before. The condensed steam is now available for feeding the boiler, and after being filtered the feed pump draws it into a heater and thence it is led into the boiler once more. If the reader will now turn to the illustration facing page 132 once more, he will see in the right hand of the picture that in the _Candia_ the feed and bilge pumps were worked by small beams from an eccentric.

By being able to use this water for the boilers a great economy was effected, but in some of the P. and O. liners the boilers suffered rather badly, since an injurious chemical action was set up owing to the continuous return of the same water backwards and forwards from the condenser. Nowadays the problems connected with the condenser have been fully mastered, and the advantage of being able to use distilled water is obvious; for one of the surest and quickest methods of bringing about ruin is to use sea-water for the boiler, over which it will lay a thick crust of salt.

The third illustration facing page 134 is interesting as representative of a type of coasting steamer introduced about the year 1855. She shows very well the simplest form of an iron ship propelled with a screw, and evinces sufficient resemblance to the dying sailing ship before the steamer had taken on a distinctive character of her own. In a word, here is the steamship not in her crudity, as in the case of the _Clermont_, but certainly in her elementary form without any of those extra decks and houses which were still to come, and which to-day give such distinct personality to the steamship. It will be seen that she is just a flush-decked vessel, with a central protection amidships for her engines and boilers. There is no forecastle, no poop, and in the development of type she stands at the beginning. She was built for the North Sea trade, and in bad weather must have been a singularly wet boat. She was only of 677 tons gross register, and the absence of any shelter would, when steaming to windward in a bad sea, cause her to be swept from end to end. Similarly, her stern being equally unprotected by either poop or quarter deck, she would be at the mercy of a bad following sea. It was not surprising that this elementary type soon gave way to those modifications that we shall see hereafter. In design of her body this present model illustrates again Scott Russell’s system of obtaining a capacious ship combined with the qualities of slipping through the water with the minimum of resistance. This will be especially noticeable by regarding the long straight middle body. She was propelled by oscillating engines, and a two-bladed screw, having also sails on her three masts.

And so we come to that famous monstrosity and wonder of her decade the _Great Eastern_, some idea of whose appearance will be obtainable from a model of her, illustrated herewith. Here again will be found a repetition of a curious rig with the half-dozen masts, of which the second and third carried yards and square-sails, and the others the usual fore-and-aft sails set on the gaffs here seen. Although she carried one triangular headsail, yet this was a staysail, and it is significant that in this notable ship we find the disappearance of the bowsprit, a change that is so characteristic of the modern liner. Much more than either the _Great Western_ or the _Great Britain_ this epoch-making monster stands for something altogether distinctive in the evolution of the steamship. Frankly, in spite of her virtues, she was a creature born out of due time. Historically, she exhibits in no uncertain manner the extraordinary and almost incredible speed at which the development of the steamship had progressed in fifty years, during which period designers, ship-builders, and engineers had to feel their way in the most cautious manner. No ship was built with such a length as hers until the White Star _Oceanic_ in 1899; no vessel ever had such a beam until the coming of the _Mauretania_ and _Lusitania_, and even they only exceed the _Great Eastern’s_ extreme width by a mere five feet. But it is half a century since the latter was built, when all the experience that we possess now was not yet obtained.

_From the Model in the Victoria and Albert Museum._]

Originally she had been named the _Leviathan_, and her beginning happened as follows: Already the fact had come to be appreciated that there was a superior advantage in a large steamer compared with a ship of smaller size when voyages of considerable distances were contemplated, and that, as already pointed out on a previous page, length of hull, other things being equal, makes for speed. In designing the _Great Eastern_ with an extreme length of 692 feet she spanned over so large a number of wave-lengths that the possibility of pitching was very decidedly reduced. But even in smooth water length still means speed, and to take the case of a rowing “eight” and compare it with a single “sculler,” we find that this law is well exemplified. Without pursuing so interesting a point beyond our limitations of subject, we might remark that quite recently an expert took the trouble to work out data obtained from the performances respectively of a Leander “eight” and a “sculler” as observed at a Henley Regatta. Although the displacement of the eight-oared craft works out at about 240 pounds per rowing man, or including the coxswain at about 217 pounds, whilst the sculler only displaces 208 lb., yet for all that the speed of the longer boat was found to be greater in the proportion as 9.75 knots are to 8.12 knots, and this, bear in mind, while the eight is carrying a ninth man who contributes nothing to the speed of the craft. We mention this as a simple example of that important fact of the superiority of length in ship-making, an importance that is now exhibited so clearly in the enormous lengths of the latest liners.

Brunel, who had already broken steamship records by his previous daring essays, suggested to the Eastern Navigation Company the building of such a ship as would be able to carry an unheard-of number of passengers, a very large amount of cargo, and at the same time be capable of steaming all the way to Australia without having to coal on the voyage. These virtues, together with her speed of fifteen knots, would, it was thought, enable her to attract such a large amount of business that she would handsomely repay her owners. The contract was eventually given to Scott Russell’s firm, who were entrusted with the building of the ship, together with the paddle-wheel engines. The screw engines were made by Messrs. James Watt and Co., so that three of the names most prominently connected with the history of the steamship were especially associated with the construction of this leviathan. Brunel was assisted in the designing by Scott Russell, and the latter’s wave-line principle was followed. The building of the ship began on the 1st of May, 1854, and on the last day of January, 1858, she was sent into the water at Millwall. But this was not done without some difficulty. The first attempt to launch this enormous mass of 12,000 tons was unsuccessful. Her weight was resting on a couple of gigantic cradles which were to slide down an incline to the water; but they only moved a few feet and then stopped. Finally, three months after the first effort, she was slowly persuaded into the water, side-ways, by hydraulic machinery. Instead of running her on the route for which she had been built, where her exceptional abilities might have been utilised, she was put to compete with the steamships already running on the Atlantic, for which short voyage she was not specially suitable, and financially she spelt ruin all round. First, the attempts to launch her, and the ensuing delay cost £120,000 and the company, unable to bear the expense, was wound up. Then the new company which bought her for £160,000 were ill-advised to employ her in the American trade, for neither as a passenger ship nor as a cargo carrier could she be made to pay her way. Subsequently she was used in laying the Atlantic cable, and was handed over to the ship-breakers in 1888, who brought her career to an end during the next couple of years.

_From the Model in the Victoria and Albert Museum._]

_From the Model in the Victoria and Albert Museum._]

The _Great Eastern_ was, in accordance with Brunel’s idea, propelled by both paddle-wheels and a screw. An illustration is here given of a model of her paddle-engines, which were of the oscillating type. It will be borne in mind that the leading advantages of this type lay in the fact of their comparative lightness in weight, and their economy as regards space. If the reader will just glance at the illustration which faces page 138 of the _Great Eastern’s_ longitudinal section, he will be able to see what little room these engines actually needed. It will be noticed in her paddle-engines that each of two cylinders drove a crank, the cylinders being placed vertically but at an inclined angle. Each paddle-wheel could, if desired, be driven separately. The condensers were of the jet type, and there were two air-pumps, which were driven by a single crank in the middle of the paddle shaft. The paddle-wheels were tremendous, weighing ninety tons each, and measuring fifty-six feet in diameter. But the _Great Eastern_ amply proved how unsuitable the paddle-wheel was for ocean work. Every time the big monster rolled in a bad sea a great strain was put on the machinery; these vast projections, too, offered not merely increased windage and accentuated the ship’s general unwieldiness, but afforded a fine target for the Atlantic waves to smash against. Once the _Great Eastern_, during a gale in the year 1861, suffered pretty badly in this respect, when the paddle-wheels were destroyed. She was afterwards fitted with wheels five feet smaller in diameter, and of greater strength.

In the next illustration will be seen a model of her screw engines, whose position in the ship will be found on referring again to the longitudinal section. These were, it will be noticed, no longer of that early type which needed gearing, but worked directly, the cylinders being placed horizontally. The number of cylinders was four, each of which had two piston-rods, and steam was supplied by half a dozen double-ended tubular boilers of the rectangular or “box” type. For the benefit of the non-technical reader we may explain that the object seen in the foreground of the picture, extending from the centre to the right-hand side, is what is commonly called the “link motion gear,” which is employed for reversing the engines when it is required to send the ship astern. This controls the slide valves which allow the steam to enter the cylinders. The principle of the link motion is just this: two eccentrics are placed side by side on the shaft, but opposite to each other. Each of them is connected by a rod to one end of the “link,” which is curved in shape. In this illustration it will be easily recognised at the right-hand side in the front. Now, as the link is moved up or down, so it controls the eccentric. If it is lowered, for instance, then one eccentric only is working the valve, but if the link is raised the other eccentric will control the valve, and so the latter will work in the opposite direction to which it did before. Thus, by using one eccentric, steam enters the cylinder at one end first, while if the other eccentric is employed steam will enter first at the other. Thus it becomes possible to make the engine turn in whichever direction is desired by regulating the end of the cylinder by which the steam shall first enter.

The _Great Eastern’s_ propeller had four blades, and an interesting arrangement was adopted so that when the ship was proceeding by means of her paddles, sails, or both, the screw propeller was kept revolving by means of two auxiliary engines in order that the speed of the ship through the water might not be diminished by the drag of the screw. Actual results showed that this ship could do her fifteen knots with screw and paddles, but her average speed was one knot less. Under screw alone she could do nine; under paddle power alone she did seven and a quarter. It will thus be noticed that when using both paddles and screw she ought to have done better, and this failing is explained by asserting that the paddle-wheels and the screw caused a resistance too great for their respective engines.

The construction of this ship calls for more space than we can here devote thereto, but some of the important features may be enumerated. She was of great strength longitudinally, and from the keel to the water-line her hull was double. The longitudinal bulkheads extended to the topmost deck, and materially added to her strength, while the inner skin just mentioned not merely gave added strength, but was an extension of the double-bottom idea, and so increased her chances in case of collision. Furthermore, the space between the two skins was available for water ballast, so as to preserve the trim of the ship as she neared the end of her voyage, and her coal bunkers were becoming lightened. Transversely, also, the ship was divided by iron bulkheads into water-tight compartments in addition to the longitudinal ones. The iron plates out of which the ship’s skin was made varied from a half to three-quarters of an inch thick. The _Great Eastern_ was able to give the world a very convincing proof of the utility of the double bottom, for she had the bad luck to run on a rock, and although more than a hundred feet of her outer hull was afterwards found to be damaged, yet she was able to complete her voyage without the water getting through into her hull proper.

For steering so large a vessel as the _Great Eastern_ the usual type of steering-wheel would clearly have entailed the expenditure of very considerable physical effort; so, for the first time, was introduced in this ship a steam steering gear, an example that is nowadays followed by almost all steamers of any size, including even excursion boats. This arrangement necessitates the use of a miniature steam engine, the two cylinders working cranks, and the shaft causing the drum containing the steering chain to revolve. Any movement of the steering wheel admits steam, and as soon as the steersman ceases to turn his wheel so quickly does the little engine cease to work.

We have no desire to try the patience of the reader by presenting a mass of statistics, but those who delight in comparisons may be interested to learn how the _Great Eastern_ would appear if put alongside the _Mauretania_. The latter displaces 40,000 tons, the _Great Eastern_ displaced 32,000. The big Cunarder is 790 feet long, between perpendiculars, while the _Great Eastern_ was 680 feet. The latter possessed a combined horse-power--paddle and screw engines--of 11,600, while the Cunarder has 70,000. And so we could continue. But now that we have seen to what unheard-of limits the steamship had shown herself capable of reaching by the end of the sixth decade in the nineteenth century--how she had, step by step, grown from moderation to exaggeration--let us now examine her progress during the next twenty years, in which she passed through her transition period.