One would think that this immense yearly addition of steamships represented in the foregoing tables would soon go beyond the world’s needs, but the almost incredible losses from wrecks, casualties, and other reasons for disappearance from the register, must be considered. There were lost or abandoned, in the fiscal year ending June 1890, 238 steamers and 588 sailing vessels of our fleet, a total of 165,508 tons; 311,220 tons disappearing in the same period from the British Register, going to swell the gigantic total of 6,795 vessels, representing 2,349,034 tons of British shipping totally lost at sea in the ten years 1880-89 inclusive.
In the face of these tremendous figures the ship-builder need not despair—he need only wait; a few slack years and the gaps in the ranks become so great that building of necessity must re-begin. The lives of ships are indeed more precarious than those of us mortals. They perish at the annual rate of about 30 in the 1,000, whereas our general chances are one-third better. But these losses of ships carry with them the lives of many brave men; with the wrecks above enumerated more than 20,000 persons perished. In this bald statement what vistas of suffering, incapacity, carelessness, negligence, misfortune, and heroism are opened up!
Despite the danger of prophecy it would seem safe to say that we shall not go, in the next five years, far beyond the changes which had taken pretty complete shape by 1887. For a while at least the startling transitions of the last decade are not to be looked for, and we can only expect greater power in greater ships on the lines already established. It is well these great transitions should not come too frequently; the ship-owner should be allowed a little breathing time, and should not be continually oppressed by a nightmare of obsolete ships. We may safely say, too, that our own country will have a greater share in shipbuilding than in past years. Our output since 1885 has been steadily increasing, and though the amount has not been great, the change wrought in our shipyards has been revolutionary. The demands of the navy have enabled them to extend and reorganize their plant and staff until they are now on a plane with the best of the world. Coincident with the transformation of the shipyards, and for the same reason, has been that of our steel industry, whereby we now have establishments which it is not Chauvinistic to say are more perfectly equipped than elsewhere.[9] If the rebuilding of the navy had served no other purpose, it had been money well spent.
Having reached this stage our builders can now take large orders much more cheaply than a few years since, and which in 1887 they could not have taken at all had it been required to supply all parts from our own industrial establishments. This fact, taken with the dawn of a new era in our commercial relations, wherein the ship-owner will have a fair chance of carrying both ways, gives good prospect of an early rehabilitation of our ancient power upon the sea.
SPEED IN OCEAN STEAMERS.
By A. E. SEATON.
The Viking’s Craft and the Modern “Greyhound”—Problems of Inertia and Resistance—Primary Condition for High Speed—What is Meant by “Coefficient of Fineness” and “Indicated Horse-Power”—Advance in Economical Engines—What the Compound Engine Effected—A Comparison of Fast Steamers from 1836 to 1890—Prejudice Against Propellers and High Pressures—Advantages of more than One Screw Propeller—Attempts at Propulsion by Turbine Wheels, Ejections, and Pumps—The Introduction of Siemens-Martin Steel in 1875 the Chief Factor in the Success of Modern Fast Steamers—Decrease in Coal Consumption—Importance of Forced Draughts—The Problem of Mechanical Stoking—Possibilities of Liquid Fuel—Is the Present Speed Likely to be Increased?
FROM the earliest days the question of the speed of ships has been one of interest to those associated with nautical matters, both from its commercial value, its value in times of emergency, and its forming the chief attraction of a pastime common to all maritime nations. There is no doubt that the emulation excited by the yacht-race of to-day does not exceed that of the ancients in their galley races. The skill of the naval architect is always more or less directed to getting the best possible speed permitted by the other conditions imposed upon him in the designing of ships of all classes, and his reputation has been, and is to-day, perhaps, more dependent on this than on any other subject connected with his profession. To-day he is faced with a competition that did not exist in the past, and his ears are constantly assailed by the cry for higher speed; and whereas a few years ago it was a common impression that the maximum limit had been reached, we have witnessed, during the past three or four years, performances by ships, both large and small, of speeds then undreamed of. It is quite true that there has existed in the minds of visionaries, whose chief occupation is to add to the receipts of the patent offices, speeds even beyond those now attained, and although it is possible that some of their predictions may be verified, it is at the same time certain that success will not be achieved by the means suggested by these gentlemen. It is common experience with shipowners and shipbuilders to have propounded to them means whereby even thirty knots per hour may be realized, and these backed up by very elaborate calculations as proof, but which, when investigated, are found, like those of a well-known writer of scientific romance, to be wanting in some little detail, insignificant at first sight, but absolutely essential to complete the proof. So far no great departure from the existing form of ship, nor from the method of propulsion, has resulted in obtaining a higher speed than is common with ordinary ships of the same dimensions; and in nearly every case such departures have mortified the inventors as well as disappointed the public by turning out absolute failures; and there is no good reason to suppose that further successes than have already been attained will be achieved in any other way than by improving the conditions that now obtain, both as regards form of ship and method of propulsion, inasmuch as the physical causes which combine to retard the motion of a vessel, and the physical forces which are employed in overcoming that resistance, remain to-day as they ever were, and are—in fact, Nature’s immutable laws. The commercial question is also one that presses very hardly at all times and must continue to do so more and more, as will be seen later on. The Atlantic greyhound of to-day is, in immersed form, substantially that of the viking’s craft of more than a thousand years ago. And if we look to Nature for our study we shall find that the swiftest fish are not unlike in general form to the submerged part of a ship; and the comparison is the more easily accepted when it is remembered that the fish is wholly submerged while the ship is only partially so. The one has to contend with waves and other surface disturbances, and must perforce keep above the water, while the other is free from such disturbing elements and conditions, and pursues its course in practically smooth water. H. B. M. S. Polyphemus is the nearest approach to the fish conditions in a sea-going ship that has proved successful.