Steamships and their story

by E. Keble Chatterton

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.

CHAPTER V
THE LINER IN HER TRANSITION STATE

The period which follows after about the year 1862 is notable as witnessing not only the gradual universal adoption of the screw in steamships, but the more general appreciation of iron as the material from which to construct a vessel’s hull. After the prejudices which already we have seen arising at different stages of the steamship’s history, it was scarcely to be wondered at that iron should come in for its full share of virulent criticism and opposition. The obvious remark made on all sides was that to expect iron to float was to suppose that man could act exactly contrary to the laws of Nature, and this notwithstanding that already, besides barges, a few ships thus built had somehow not only managed to keep afloat, but to traverse channels and oceans in perfect safety, carrying such heavy weights as their own machinery, to say nothing of their cargoes and human freights. But slowly the public prejudice began to wane. Already the Cunard Company had given way to iron in 1856, and in 1860 the Admiralty were at last convinced that the new method was just and sound. Within the limited scope at our command we have not space here to enter into the elaborate discussion of matters which have to be taken for granted before the building of the steamship begins. But the plain answer to the natural inquiry, as to how and why a vessel made out of iron does not immediately sink to the bottom as soon as ever she is launched, is this: whereas iron in itself is far heavier than water, yet the iron ship has not the same specific gravity as the iron from which it is made. Therefore, the ship of this material will be supported by the water in which it is placed.

In actual displacement, an iron ship is proportionately lighter than a ship built of wood, and by “displacement” is meant the amount of water which a vessel displaces through being allowed to float. Of course, the quantity of water which a ship displaces (or pushes to one side) depends entirely on the weight of the vessel, and is exactly equal to the weight of the ship. Thus, suppose we were to fill a dock with water up to the level of the quay and then lower down into it by means of gigantic cranes a Mauretania or Lusitania, the water would, of course, flow over on to the quays. Now the amount of water thus driven out would be the exact equivalent of the liner’s displacement. When we say, for instance, that the displacement of the Mauretania is 40,000 tons, when loaded, we mean that her total weight when loaded is this number of tons, and her hull when afloat puts on one side (or “displaces”) just that amount of water.

Now, as compared with wooden ships, the use of iron meant a saving in displacement of about one-third, taking the wooden and the iron ships to be of the same dimensions. From this followed the fact that the iron ship could carry a greater amount of cargo with consequent greater profit to her owners. And, as I have already indicated in another chapter, before it was possible to build ships of great length iron had to be introduced to enable them to endure such longitudinal strains. Again, a wooden ship must have her skin and ribs made of a thickness far greater than an iron ship, for the clear reason that one inch of iron is much stronger than one inch of wood; in other words, to obtain a given strength the iron will take up less room in the ship. Thus in an iron steamer there will be more space available for cargo than in a wooden ship of the same design. We could go on enumerating the advantages of iron, and quote instances of iron ships, whose cargo had got on fire, arriving safely in port and coming into dock where the assistance of the local fire-brigade had enabled the vessel’s own pumps to get the conflagration under. It is only as recently as December of 1909 that the Celtic, the well-known White Star liner, during a voyage between New York and Liverpool, had the misfortune to get on fire while at sea. By means of tarpaulins and injections of steam it was possible to control the burning until the Mersey was reached, when it was intended to flood her holds. Had she been a wooden ship instead of steel, or even iron, the Celtic would undoubtedly have ended her days in the Atlantic.

The first Atlantic company to build all its steamers of iron was the Inman Line, which had been founded in 1850, and until 1892 was one of the foremost competitors for the coveted “blue ribbon” of the Atlantic. Their first ships had been the City of Glasgow and the City of Manchester, and these, inasmuch as they were built of iron, and were propelled by a screw at a time when prejudice had not yet died down, were entirely different from the prevailing type of steamer; and this, it should be remembered, at a period six years before the Cunard had built their iron Persia. This City of Glasgow was built by a Glasgow firm of shipbuilders, and Mr. Inman had sufficient confidence in her to purchase her and form a company. Barque-rigged, with a single funnel, she was of only 1,610 tons and 350 horse-power. Under the command of Captain B. E. Matthews, who had been on the famous Great Western, she had already crossed from Glasgow to New York and back in 1850, and on December 11th of that year began her regular sailings between England and America. The City of Glasgow—all the ships of this line were named after cities—was fitted up in a manner which at that time called forth the greatest admiration. “One room,” wrote a correspondent in the Glasgow Courier, about that date, “is being fitted up as an apothecary’s shop, from which the surgeon will dispense his medicines.” She was provided with five water-tight bulkheads, and had a propeller whose diameter was 13 feet, with an 18 feet pitch. It was in connection with the Inman ships that the custom was inaugurated of carrying steerage passengers on the best Atlantic liners, although hitherto they had been taken across solely on board sailing ships.