Читать книгу Ocean Steamships - J. D. Jerrold Kelley - Страница 5
ОглавлениеModel of the Persia and Scotia.
Diagram showing Decrease in Expediture of Coal per indicated Horse-power per hour based on Good Average Practice
Diagram showing increase in Steam-pressures based on good average Practice
How great an advantage she was upon their first ship will be seen by the following comparison:
| Britannia. | Persia. | |
|---|---|---|
| Coal necessary to steam to New York | 570 tons | 1,400 tons |
| Cargo carried | 224 „ | 750 „ |
| Passengers | 90 | 250 |
| Indicated power | 710 | 3,600 |
| Pressure per square inch | 9 lbs. | 33 lbs. |
| Coal per indicated horse-power per hour | 5.1 „ | 3.8 „ |
| Speed | 8.5 knots | 13.1 knots |
Thus, for two and a half times the quantity of coal nearly three and a half times the cargo was carried, and nearly three times the number of passengers. This result was due partially to increased engine efficiency, and partially to increased size of ship; and thus to a relative reduction of the power necessary to drive a given amount of displacement.
The Scotia was almost a sister ship to the Persia, slightly exceeding her in size, but with no radical differences which would mark her as an advance upon the latter. She was the last of the old régime in the Atlantic trade, and the same year in which she was built saw the complete acceptance by the Cunard company of the newer order of things, in the building of the iron screw steamer China, of 4,000 tons displacement, with oscillating geared screw engines of 2,200 indicated horse-power, with an average speed of 12.9 knots on a daily expenditure of 82 tons of coal. She was the first of their ships to be fitted with a surface condenser. The Scotia had been built as a paddle steamer rather in deference to the prejudices of passengers than in conformity to the judgment of the company, which had put afloat iron screw ships for their Mediterranean trade as early as 1852 and 1853.
The introduction of surface condensation and of higher pressures were the two necessary elements in a radical advance in marine engineering. Neither of these was a new proposal;3 several patents had been taken out for the former at a very early date, both in America and in England; and in 1838 the Wilberforce, a boat running between London and Hull, was so fitted. Very high pressures, from almost the very beginning, had been carried in the steamers on our Western waters; and in 1811 Oliver Evans published, in Philadelphia, a pamphlet dealing with the subject, in which he advocated pressures of at least 100 to 120 pounds per square inch, and patented a boiler which was the parent of the long, cylindrical type which came into such general use in our river navigation. The sea-going public resolutely resisted the change to high pressures for nearly forty years, there being a very slow and gradual advance from 1 and 2 pounds to the 8 and 9 carried by the Great Britain and Britannia. In 1850 the Arctic carried 18 and in 1856 25 was not uncommon. Some of the foremost early engineers favored cast-iron boilers (see evidence before parliamentary committee, 1817); and the boiler in general use in England up to 1850 was a great rectangular box, usually with three furnaces and flues, all the faces of which were planes.4
Longitudinal Section of the Warship Duilio.
Larger image (157 kB)
Though tubular boilers did not displace the flue boiler in British practice to any great degree before 1850, many examples were in use in America at that date, but chiefly in other than sea-going steamers. Robert L. Stevens, of Hoboken, built as early as 1832 “the now standard form of return tubular boilers for moderate pressures” (Professor R. H. Thurston). But it worked its way into sea practice very slowly; and the multitubular boiler, in any of its several forms, cannot be said to have been fairly adopted in either American or British sea-going ships before the date first mentioned, though employed in the Hudson River and Long Island Sound steamers, in one of the former of which, the Thomas Powell, built in 1850, a steam pressure of 50 pounds was used.
The Britannic.
Larger image (112 kB)
There had been this slow and gradual advance in ocean steam pressures, with a consequent reduction in coal expenditure, when in 1856 came a movement in the direction of economy by the introduction of the compound engine, by Messrs. Randolph Elder & Co. (later John Elder & Co.), which was soon to develop into a revolution in marine steam enginery. The Pacific Steam Navigation Company has the credit of first accepting this change in applying it to their ships, the Valparaiso and Inca. The original pressure used was 25 pounds to the inch: the cylinders were 50 and 90 inches in diameter, and the piston speed from 230 to 250 feet per minute. The idea of using steam expansively by this means was of course not new, as it dates back to Hornblower (1781), but with the low pressures which had been used at sea there was no reason for its adoption afloat. Difficulties were experienced by the Pacific company with their earlier engines, but the line adhered to their change, and for nearly fourteen years were almost alone in their practice.
These changes made the use of a cylindrical boiler necessary, as the form best able to withstand the increased pressure. The old box-like shape has disappeared; and if the shade of Oliver Evans is ever able to visit us, it must be with an intense feeling of satisfaction to find his ideas of eighty years since now accepted by all the world.
The date 1870 marks the advent of a new type of ship, in those of the Oceanic Company, better known as the White Star line, built of iron by Harland & Wolff, of Belfast—engined with compound engines, and of extreme length as compared with their breadth. They established a new form, style, and interior arrangement, which has largely been followed by other lines, though the extreme disproportion of length and beam is now disappearing. The Britannic and Germanic, the two largest of the earlier of this line, are 468 feet in length and 45 feet 3 inches in beam, carrying 220 cabin passengers and 1,100 in the steerage, besides 150 crew. They develop 5,000 indicated horse-power, and make their passage, with remarkable regularity, in about 8 days 10 hours to Queenstown. The earlier ships of this line, when first built, had a means of dropping their propeller-shaft so as to immerse more deeply the screw; so many inconveniences, however, were associated with this that it was given up. Their general arrangement was a most marked advance upon that of their predecessors—an excellent move was placing the saloon forward instead of in the stern, a change almost universally followed.
In the same year with the Britannic came out the City of Berlin, of the Inman line, for some years the largest steamer afloat (after the Great Eastern), being 520 feet in length by 44 feet beam, of 5,000 indicated power, and in every way a magnificent ship.
The Bothnia and Scythia were also built in 1874, by the Cunard company, as representatives of the new type, but were smaller than the ships of the same period built by the Inman and White Star lines. They were of 6,080 tons displacement and 2,780 indicated horse-power, with a speed of 13 knots. The pressure carried was 60 pounds. These ships had by far the largest cargo-carrying capacity (3,000 tons measurement) and passenger accommodation (340 first-cabin) of any yet built by the company. With the addition of this great number of steamers, change was not to be expected for some years; and it was not until 1879, when the Guion company put afloat the Arizona, that a beginning was made of the tremendous rivalry which has resulted in putting upon the seas, not only the wonderful ships which are now running upon the Atlantic, but in extending greatly the size and speed of those employed in other service.
Several things had combined in the latter part of this decade to bring about this advance. The great change between 1860 and 1872, from the causes already noted, which had reduced coal consumption by one-half, was followed by the introduction of corrugated flues and steel as a material for both boilers and hull. With this came still higher pressures, which were carried from 60 to 80 and 90 pounds. In August, 1881, a very interesting paper was read by Mr. F. C. Marshall, of Newcastle, before the Institution of Mechanical Engineers, in which he showed that a saving of 13.37 per cent. in fuel had been arrived at since 1872. The general type of engine and boiler had remained the same in these nine years, but the increased saving had been due chiefly to increased pressures. It is curious that at the reading of both the paper by Sir Frederick Bramwell, in 1872, and that of Mr. Marshall, in 1881, there should have been pretty generally expressed a feeling that something like a finality had been reached. So little was this opinion true that, though over thirteen per cent. saving had been effected between these two dates, a percentage of gain more than double this was to be recorded between the latter date and 1886. In these matters it is dangerous to prophesy; it is safer to believe all things possible. Certainly the wildest dreamer of 1872 did not look forward to crossing the Atlantic at 20 knots as a not unusual speed.
The Etruria
Larger image (178 kB)
In 1874 triple-expansion engines had been designed for the Propontis by Mr. A. C. Kirk, of Napier & Sons, of Glasgow, which, on account of failure in the boilers which were used, did not give at first the results hoped for. In 1881 the Messrs. Napier fitted the Aberdeen with engines of the same kind, steam at 125 pounds pressure per square inch being used. In the next two years the change proceeded slowly, but by 1885 the engineering mind had so largely accepted it that a very large proportion of the engines built in that year were on this principle, and at the present it may be regarded as being fully accepted as was the compound engine ten years since. The saving in fuel is generally reckoned at from twenty to twenty-five per cent., or, to put it more graphically, in the words of Mr. Parker, Chief Engineer Surveyor of Lloyds, in his interesting paper, read in July, 1886, before the Institution of Naval Architects: “Two large passenger steamers, of over 4,500 gross tonnage, having engines of about 6,000 indicated horse-power, built of the same dimensions, from the same lines, with similar propellers, are exactly alike in every respect, except so far as their machinery is concerned. One vessel is fitted with triple-expansion engines, working at a pressure of 145 pounds per square inch; while the other vessel is fitted with ordinary compound engines, working at a pressure of 90 pounds per square inch. Both vessels are engaged in the same trade and steam at the same rate of speed, viz., 12 knots an hour. The latter vessel in a round voyage of 84 days burns 1,200 tons more coal than the former.”
In the epoch 1879 to 1887 the following great ships had been placed upon the Liverpool and New York lines, their best speeds to that date being as shown:
| Days. | Hours. | Minutes. | |
|---|---|---|---|
| 1. Etruria | 6 | 5 | 31 |
| 2. Umbria (sister ship) | slightly longer | ||
| 3. Oregon | 6 | 10 | 35 |
| 4. America | 6 | 13 | 44 |
| 5. City of Rome | 6 | 18 | 0 |
| 6. Alaska | 6 | 18 | 37 |
| 7. Servia | 6 | 23 | 55 |
| 8. Aurania | 7 | 1 | 1 |
The time had thus been shortened much more than half since 1840, and had been lessened forty per cent. since 1860.
In addition to the ships mentioned, there had been placed upon the line from Bremen to New York (between 1879 and 1886) touching at Southampton, England, eight new ships of the North German Lloyd, which form 28 altogether, the most compact and uniform fleet upon the Atlantic. The Trave, Saale, and Aller, were then marvels of splendor and comfort, ranking in speed and power very little short of the fastest of the Liverpool ships. They, as were the others of the company’s eight “express” steamers, were built by the great firm of John Elder & Co., of Glasgow, their machinery being designed by Mr. Bryce-Douglas, to whose genius was also due that of the Etruria and Umbria, the Oregon, Arizona, and Alaska. The engines of the Trave, Saale, and Aller, however, were triple-expansion, as were the Gascogne, Bourgogne, and Champagne (their equals in speed and equipment), of the French Compagnie Transatlantique, which were built in France. All these steamers are of steel, with cellular bottoms carefully subdivided, and fitted with a luxury and comfort quite unknown thirty years ago.
Cross-section of the Oregon.
Cross-section of the Servia.
Triple-expansion Engine of the Aller, Trave, and Saale.
It was difficult, if not almost impossible, to go beyond them without a change to twin screws. If more than the Umbria’s power was to be developed it was safer to use it through two shafts, and the depth of water on the New York bar is a hindrance to the use of a much greater diameter of screw. Mr. Griscom, of Philadelphia, was the bold manager to take the first step by laying down the Inman Company’s ships in 1887, the first of which, the City of New York, was ready for trial in thirteen months after the signing of the contract with Messrs. James & George Thompson, of Clydebank: a wonderful performance. The Teutonic and Majestic quickly after took shape in the yard of Messrs. Harland & Wolff, of Belfast, the place of birth of all of the White Star fleet. These two lines were thus the first to accept the changed conditions, and the City of New York and City of Paris of the former, and the Teutonic and Majestic of the latter, still mark the high-water mark of achievement, both as regards performance as a machine and the comfort and luxury of the passenger. The “Cities,” as they are familiarly termed, are 560 feet in length, by 63 feet broad, displace 13,000 tons, and indicate over 18,000 horse-power. The two White Stars are 582 feet long, by 57 feet 6 inches broad, of 12,000 tons displacement, and of nearly equal horse-power with their two great competitors. In less than twenty years these lines had thus nearly doubled the size of their ships, and more than tripled their power.
Longitudinal Section of the Champagne.
Larger image (143 kB)
It may be of interest to the American public to know that the City of New York and City of Paris are but two of the largest fleet under one management on the North Atlantic. Though under one control it is under three flags—English, Belgian, and American—our own, thanks to the wisdom of Congress, covering but a small contingent, though our law-makers for several years have been besieged to allow them to become American in nationality as well as ownership. It would certainly seem that they were quite as worthy of it as some of our importations of another kind, but we shall probably have to wait for a little more breadth of thought and idea under the dome at Washington before this change can be brought about.
The building of these four ships seems to have given an impetus to the whole of the steamship world: the Hamburg-American lines started into new life with the Columbia, Normannia, Augusta Victoria, and Fuerst Bismarck, twin screws of 9,500 and 10,500 displacement, which have averaged in their best runs from New York to Southampton 19.01, 18.91, 18.31, and 19.78 knots in the order named, the distance being about 3,075 knots.
The French Company has added the twin-screw Touraine of 11,675 tons and 181⁄2 knots sustained speed to their already splendid fleet, and the North German Lloyds have since 1887 built the Lahn, Spree, and Havel, all single screws; and the two last of 7,000 tons with 13,000 horse-power and a speed of 181⁄2 knots. These latter ships would probably have been twin screws had the docks of Bremerhaven afforded sufficient width of entrance; but whether this be the case or not, the probability is that in the future it will be the dock which will yield and not the ship. There is no need to make comparison of these ships in equipment. Luxury has been carried as far as the present human invention and imagination can take it. Suites for families are arranged with private sitting-rooms and private tables, so that, barring the roll so uneasy to the unhappy landsman, one could scarce know the change from the most luxurious apartment of the Brevoort.
Such are the ships of to-day, but displacement from their eminence is already in discussion. The builders of the City of New York are guaranteeing a vessel to cross the Atlantic in 5 days, or at a speed of 231⁄2 knots, the probable elements of this projected vessel being given by Engineering as a length of 630 feet and a beam of 70, with 33,000 indicated horse-power. It is a long step, but one can hardly doubt it will soon be taken.
But that this step will be greatly aided by any material change in the marine steam engine in the very near future is not probable, the difficulty is now not with the engine but with the boiler; forced draught and the higher pressures call imperatively for a new development in the steam producer; leaky tubes and joints and a rapid deterioration through the effort to keep up the high pressures necessary for the successful performance of the new type of engine are the shortcomings which must be successfully combated before we can make another great advance. Unfortunately there is another draw-back, for which the remedy will be even more difficult, the suffering of the firemen induced by the greater heat of the higher pressures. Let us hope that genius will yet invent a mechanical stoker and that we may not of necessity subject our fellow-beings to the 140° too frequently found in our modern fire-rooms.
We may fitly place here a tabulation of the very wonderful achievements of the ships first mentioned, based on official data in Engineering of June 19 and July 10, 1891, and covering, in the case of the Liverpool ships, the season of 1890, except for the City of Paris, which is for 1889. (See table on p. 45.)
The coal consumption is also officially stated by the journal from which the above is compiled as follows: The City of New York, 328 tons: Teutonic, 316 tons: Etruria, 330 tons. This shows an actual expenditure of about 1.6 lb. per hour in the case of the Teutonic: slightly greater for the City of New York, and over 1.9 for the Etruria.
But in the month of August, 1891, both the Teutonic and Majestic won still greater laurels, the latter crossing from Queenstown to New York in 5 days 18 hours and 8 minutes; the former in 5 days 16 hours and 31 minutes, and averaging for the run of 2,778 miles 20.35 knots per hour, the best day’s run being 517 knots.
Fastest Passages of the more Important Steamers between New York and English Ports during the Season of 1890. 5
| Name | Dimensions: Length, Breadth, Depth | Displacement | Piston Stroke | Boiler Heating Surface |
|---|---|---|---|---|
| New York and Queenstown | Tons. | Feet. | Sq. Ft. | |
| City of Paris | 560 × 63 × 43 | 13,000 | 5 | 50,265 |
| City of New York | 560 × 63 × 43 | 13,000 | 5 | 50,040 |
| Majestic | 582 × 571⁄2 × 591⁄8 | 12,000 | 5 | 40,972 |
| Teutonic | 582 × 571⁄2 × 591⁄8 | 12,000 | 5 | 40,972 |
| Etruria | 5011⁄2 × 57.2 × 38.2 | 10,500 | 6 | 38,817 |
| Umbria | 5011⁄2 × 57.2 × 38.2 | 10,500 | 6 | 38,817 |
| City of Rome | 546 × 52 × 583⁄4 | 11,230 | 6 | 29,286 |
| New York and Southampton | Inches | |||
| Columbia | 480 × 56 × 38 | 9,500 | 66 | 34,916 |
| Normannia | 520 × 571⁄4 × 38 | 10,500 | 66 | 46,490 |
| Augusta Victoria | 480 × 56 × 36 | 9,500 | 63 | 36,000 |
| Lahn | 448 × 49 × 361⁄2 | 7,700 | 72 | … |
| Name | Grate Area | Steam Pressure | I.H.P. | Fastest Trip | Direction |
|---|---|---|---|---|---|
| New York and Queenstown | Square Feet | Lbs. | D. H. M. | ||
| City of Paris | was 1,293 now 1,026 | 150 | 18,350 | 5 19 18 | Westward |
| City of New York | was 1,080 now 1,096 | 150 | 18,100 | 5 21 19 | Westward |
| Majestic | 1,154 | 180 | 18,000 | 5 21 20 | Westward |
| Teutonic | 1,154 | 180 | 18,000 | 5 19 5 | Westward |
| Etruria | 1,606 | 110 | 14,300 | 6 6 57 | Westward |
| Umbria | 1,606 | 110 | 14,300 | 6 3 29 | Westward |
| City of Rome | 1,398 | 90 | 11,890 | 6 22 30 | Eastward |
| New York and Southampton | |||||
| Columbia | 1,226 | 150 | 13,680 | 6 15 0 | Eastward |
| Normannia | 1,452 | 160 | 16,352 | 6 17 2 | Westward |
| Augusta Victoria | 1,120 | 150 | 14,110 | 6 22 32 | Eastward |
| Lahn | … | 150 | 9,500 | 7 3 0 | Eastward |
| Name | Month | Distance | Average Speed | Average for Eight Months | Fastest Day’s Run during Season |
|---|---|---|---|---|---|
| New York and Queenstown | Knots | Knots | Knots | Knots | |
| City of Paris | August | 2,788 | 20.01 | 19.02 | 515 |
| City of New York | October | 2,775 | 19.64 | 19.02 | 502 |
| Majestic | September | 2,780 | 19.64 | 19.00 | … |
| Teutonic | August | 2,806 | 20.18 | 18.84 | 512 |
| Etruria | July | 2,845 | 18.80 | 18.29 | 481 |
| Umbria | August | 2,835 | 19.20 | 18.15 | 498 |
| City of Rome | Aug.-Sep. | 2,787 | 16.73 | 16.18 | 424 |
| New York and Southampton | |||||
| Columbia | October | 3,045 | 19.15 | 18.68 | 492 |
| Normannia | August | 3,045 | 18.91 | 18.41 | 486 |
| Augusta Victoria | September | 3,049 | 18.31 | 17.52 | 470 |
| Lahn | October | … | … | 17.29 | … |
Note.—The nautical mile is one-sixtieth of a degree of the Equator, and is usually reckoned 6,080 feet, the statute mile being 5,280; twenty nautical miles are thus about twenty-three statute miles. The shortest distance is the arc of the great circle of the Earth passing through the two ports; any deviation from this by varying the course on account of intervening land or ice increases the distance to be run.
The crown is thus for the moment with the White Star, nor is it likely to be torn away by anything short of the tremendous effort involved in putting afloat a new, a bigger, and a more costly ship. Owners must, of course, count the cost of such rivalry and must put against the gain of say sixteen hours, in order to come to the desired five days and twenty-three knots, the cost of the thousand or twelve hundred tons more of coal which will have to be burned, the doubled number of engine and fire-room force, the larger crew, the interest on the greater investment. It is a large price to pay for a gain of so small a bit of that we generally hold so cheap—but it will be paid.
It has been impossible, of course, in a single chapter to do more than touch upon the vast changes, and their causes, which have had place in this great factor of human progress. Higher pressures and greater expansions: condensation of the exhaust steam, and its return to the boiler without the new admixture of sea-water, and the consequent necessity of frequent blowing off, which comparatively but a few years ago was so common; a better form of screw; the extensive use of steel in machinery, by which parts have been lightened, and by the use of which higher boiler-pressures are made possible—these are the main steps. But in addition to steel, high pressures, and the several other elements named which have gone to make up this progress, there was another cause in the work chiefly done by the late W. Froude, to be specially noticed as being that which has done more than the work of any other man to determine the most suitable forms for ships, and to establish the principles governing resistance. The ship-designer has, by this work, been put upon comparatively firm ground, instead of having a mental footing as unstable, almost, as the element in which his ships are destined to float.
It is not possible to go below the surface of such a subject in a popular paper, and it must suffice to speak of Mr. Froude’s deductions, in which he divided the resistances met by ships into two principal parts: the surface or skin friction, and the wave-making resistance (which latter has no existence in the case of a totally submerged body—only begins to exist when the body is near the surface, and has its full effect when the body is only partially submerged). He showed that the surface friction constitutes almost the whole resistance at moderate speeds, and a very great percentage at all speeds; that the immersed midship section area which formerly weighed so much in the minds of naval architects was of much less importance than was supposed, and that ships must have a length corresponding in a degree to the length of wave produced by the speed at which they are to be driven.
The Chilian Cruiser Esmeralda.
Larger image (159 kB)
He showed that at high speeds waves of two different characters are produced: the one class largest at the bow, which separate from the ship, decreasing in successive undulations without afterward affecting her progress; the other, those in which the wave-crests are at right angles to the ship’s course, and the positions of these crests have a very telling effect upon the resistance.
As the ship’s speed is increased the spaces between the crests of these lengthen in unison with the speed, and it has been shown that when the speed is such that a wave-crest would be at the middle point of the after body (or quarter) the wave-making resistance is least, and that it is greatest when the hollow appears at this point.
A ship must therefore be of a length that depends largely upon the length of wave which at a high speed she will tend to produce in order that she may be driven at such a speed without an expenditure of power disproportionate to the effect produced. This length, if very high speeds are desired, is best wholly taken up in fining the entrance and run, leaving no parallelism of middle body, and broadening and deepening the ship to keep the necessary displacement. The wave-action at several speeds is well shown in the illustrations, which are from instantaneous photographs, showing the Chilian cruiser Esmeralda at her full speed of 18 knots, when on her trial off Newcastle-upon-Tyne, the Giovanni Bausan, of the Italian navy (almost a sister ship to the Esmeralda), at a moderate speed, and H.M.S. Impérieuse, at about 171⁄4 knots. [See illustration, p. 64.] The following are the principal details of the Esmeralda and Impérieuse:
| Displacement. | Length. | Beam. | Draught. | Horse-power. | |
|---|---|---|---|---|---|
| Esmeralda | 3,000 | 270 | 42 | 18.3 | 6,500 |
| Impérieuse | 7,390 | 315 | 62 | 26.0 | 10,180 |
The eddy-making resistance is greater or less, of course, as the form is blunted or finer, and there is less resistance with a blunt bow and finely formed after-body than were the two reversed. Our practical towing friends will be glad to know that Mr. Froude substantiates their oft-reiterated assertion that a log tows more easily butt-end foremost. In the Merkara, a merchant ship built by Mr. Denny, of 3,980 tons, 360 feet length, 37.2 feet breadth, and 16.25 feet draught, this resistance is, at all speeds, about eight per cent. of the surface friction, which at the maximum speed of thirteen knots, at which she was intended to be run, still formed nearly eighty per cent. of the whole resistance.
A very wonderful result of these experiments has been to show (in the words of Mr. Froude) “what an exceedingly small force, after all, is the resistance of a ship compared with the apparent magnitude of the phenomena involved. Scarcely anyone, I imagine, seeing the new frigate Shah (of 6,250 tons displacement) steaming at full speed (from sixteen to seventeen knots) would be inclined, at first sight, to credit what is nevertheless a fact, that the whole propulsive force necessary to produce that apparently tremendous effect is only 27 tons—in fact, less than one two-hundredth part of the weight of the vessel—and of this small propulsive force at least 15 tons, or more than one-half, is employed in overcoming surface friction simply.”
The Giovanni Bausan, of the Italian Navy. (From an instantaneous photograph.)
Larger image (176 kB)
Of course, very small vessels, as torpedo-boats, have been driven at very high speeds, but the power necessary is in enormous disproportion as compared with the above, a development in 135-foot torpedo boats of from 1,000 to 1,500 horse-power and more being not uncommon.
The acceptance of the results of Mr. Froude’s deductions has naturally led to an increase in the beam of fast ocean steamers; we find all the later-built to be much broadened, and there is a still increasing tendency in that direction. It is needless to say how much this means in many ways to the passenger.
The Belted Cruiser Orlando, with Twin Screws.
Larger image (164 kB)
Collision will and must remain the great and really almost the one danger which the North Atlantic traveller need fear. He can rarely hope to cross in the usual steam route without experiencing a run of some hundreds of miles through fog, especially on leaving or approaching our coast. So long as the Gulf Stream and the cold inlying current from the north move in juxtaposition as they do, so long will the fog be almost always present upon the border-land dividing them. How easy it is for a great ship to be sunk was shown in the case of the Oregon. A blow from a pygmy schooner not more than one-tenth her size, and a hole was opened through her side which unfortunate circumstances combined to make fatal, and the great vessel, a triumph of human skill in hull and machinery, is lying in a few hours upon the bottom of the sea, with a million days of skilled labor, as represented by ship and cargo, in this moment made valueless. Who can over estimate the care and responsibility upon the man who commands such a ship? In what other calling are they found as such a constant part of daily life?
The only remedy for such an accident as that which befell the unluckly Oregon seems to be a subdivision such as is carried out in all the greater ships of late years; and that this has been carried to a degree which has made the finer passenger ships practically unsinkable, unless under most exceptional circumstances, would seem quite sure.6
How wonderful has been the scale upon which this great industry of carriage by steam vessels has grown can only be shown by tables of statistics.
The steam tonnage in the United States, Great Britain, France, and Germany, beginning with 1840, was as follows:
