Steamships and their story

by E. Keble Chatterton

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.

PADDLE ENGINES OF THE “GREAT EASTERN.”

From the Model in the Victoria and Albert Museum.

SCREW ENGINES OF THE “GREAT EASTERN.”

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.