Chapter 3

Next we must attack the extravagant furnace, and increase its area and reduce the depth of the bed of coal. The difficulty of making this change seemed to me to be removed, on examining an engine on the Providence & Bristol Railroad, the other day. The machine was made at the Mason Works, of Taunton. It was an engine and tender combined, the truck being at the rear end of the tender, and the driver placed well in advance of the fire-box, so that the maximum weight of both engine and tender rested upon the drivers. In thus removing the drivers from the proximity of the fire-box, abundant facility is afforded for widening the fire-box, so as to obtain a grate area as large as that of the Wootten engine or of a stationary boiler. It seems to me the increase of grate area can be obtained only by widening; for a length of more than six or seven feet is very hard upon the fireman. You certainly cannot get more power by deepening present fire-boxes, except by an enormously increased waste of fuel, which all will concede is already sufficiently extravagant.

In arriving at the conclusion of these hasty and I fear somewhat incoherent remarks, I would say that the object aimed at for the improvement of the locomotive would be reached, first, by making steam economically, by employing such increased grate area as will permit running thin fires and moderate or comparatively slow draught; and, secondly, in economically using the steam which has been economically made by compounding the engine.

I have given you merely the views of an "outsider," who has had a somewhat extensive experience in stationary engineering, and who has observed locomotive practice in many parts of the world. These views are offered for what they are worth, as suggestions for future thought in designing engines, and as a sort of refresher upon rudimentary points which long familiarity with every-day phenomena causes us at times to overlook. I trust that your deliberations may aid in the speedy reduction of the expenses of transporting freight and passengers, for the benefit of the railroad companies and, in their turn, the advantage of the people at large.

* * * * *

ATLANTIC STEAMERS.[1]

[Footnote 1: A paper recently read before the Institution of Naval Architects.]

By W. JOHN.

The author said that he hoped to bring before the meeting impartially certain facts which might be of interest, and which, when recorded in the pages of the "Transactions," might be found of some use as data for future reference. In dealing with passenger steamers, he would do so principally from a shipbuilder's point of view; but the moment he commenced to think over Atlantic passenger ships as a shipbuilder, he was met by the question whether the present tendency toward divorcing the passenger and cargo trade from each other is likely to continue or not. If the answer is yes, then it seems to become an important question, for the present at least, how to build, on moderately small dimensions, the fastest, safest, and most economical passenger steamer, using all the most modern improvements to make her commodious and luxurious, and an easy sea boat into the bargain. If cargo is still to be carried in the passenger ships of the future, a moderate speed only will be aimed at in the immediate future, and every effort will be devoted to economy of fuel, comfort, and safety, with a fair carrying capacity. This latter policy is one which may possibly prevail at least for a time, as it has powerful supporters in Liverpool; but he could not help thinking that very high speeds--higher than we have yet attained--must eventually gain the day. He also thought that they were on the eve of important movements, which will indicate what the next step in the passenger trade is to be; for it must be remembered, among other things, that none of our present English transatlantic liners, even the latest, have yet been fitted with the latest modern improvements for economy of fuel or quick combustion, such as triple expansion engines or forced draught. They must, therefore, be at some disadvantage, other things being equal, compared with the ships of the future possessing them. The Great Eastern steaming up Milford Haven about twenty-five years ago between two lines of the channel fleet of old--two and three decked wooden line-of-battle ships--the whole fleet saluting with yards manned, was a sight to be remembered. More than this, that ship, with all her mournful career, has been a useful lesson and a useful warning to all naval architects who seriously study their profession--a lesson of what can be done in the safe construction of huge floating structures, and a warning that the highest flights of constructive genius may prove abortive if not strictly subordinated to the practical conditions and commercial requirements of the times. The Sirius and Great Western crossed the Atlantic in 1838, and in 1840 the first ship of the since celebrated Cunard Company made her first voyage. This was the Britannia, which, with her sister ships, the Arcadia, Caledonia, and Columbia, kept up the mail service regularly at a speed of about 8½ knots an hour. The Britannia was 207 ft. in length between perpendiculars, and 34 ft. 4 in. extreme breadth, 22 ft. 6 in. depth of hold, 423 horse power--nominal--and 1,153 tons burden, built of wood, and propelled by paddles. In 1860 the Collins Line started in opposition to the Cunard, and, after a series of disasters, collapsed in 1858. This was three years after the Persia, the first Cunarder built of iron, had been completed. In 1850, also, the Inman Line was started with the City of Glasgow, of 1,600 tons builders' measurement, and 350 horse power. She was built of iron, and was the first screw steamer sent across the Atlantic from Liverpool with passengers, and was the pioneer of the great emigrant trade which Mr. Inman, above all others, did so much to develop and make cheap and comfortable for the emigrants themselves, as well as profitable to his company. That the builders of the celebrated old Great Britain, in 1843, and Mr. Inman, in 1850, should have pronounced so decisively in favor of the screw propeller in preference to the paddle for ocean steaming is a proof of their true practical judgment, which time and practical experience have made abundantly clear. While the Cunard Company went on developing its fleet from the early wood paddle steamer Britannia of 1,130 tons in 1840 to the iron paddle steamers Persia, etc., in 1858, the iron screw steamer China of 1862, to the still more important screw steamers Bothnia and Scythia, vessels of 4,335 tons, in 1874, the Inman and other lines were as rapidly developing in speed and size, if not in numbers. The year 1874 is memorable, for it saw the White Star steamers Britannic and Germanic put into the water, as well as the Inman steamer City of Berlin and the two before mentioned Cunard steamers, Bothnia and Scythia. By the addition of these two ships to their fleet the White Star Line, although started only in 1870, reached a front rank position in the New York passenger trade. The author gave in separate tables the logs of several of these ships, some from published documents and some kindly furnished by the owners. The Great Western had crossed the Atlantic from Bristol to New York in 15 days as early as 1838. The first Cunard steamer, the Britannic, was about the same speed, from 8¼ to 8½ knots an hour. The average duration of the Cunard voyages in the year 1856 was 12.67 days from Liverpool to New York, and 11.03 days from New York to Liverpool. The Bothnia, in 1874, reduced the passage to about nine days. The White Star Britannic, in 1876, averaged 7 days 18 hours 26 minutes outward from Queenstown to New York, and 9 days 6 hours 44 minutes homeward, and has averaged for the last ten years 8 days 9 hours 36 minutes outward, and 8 days 1 hour 48 minutes homeward. The City of Berlin, of the Inman Line, also built in 1874, 8 days 10 hours 56 minutes, and homeward 8 days 2 hours 37 minutes; and for the nine years from 1875 to 1883 inclusive, averaged outward 8 days 19 hours 56 seconds, and inward 8 days 8 hours 34 seconds; or, putting it into rounder figures, the Britannic had reduced the average passage between the two points to 8¼ days, and the City of Berlin to 8½ days. From the year 1874 on to 1879 no further advance was made in Atlantic steaming, but in that year the Arizona was added to the Guion Line, and it soon became evident that another important stride had been made in the Atlantic passenger trade, which would lead to most important results. The results, as we all know, have been sufficiently startling. The Guion Line, which had started in 1866 with the Manhattan, had now the fastest passenger ship on the Atlantic. In spite of burning some fifty per cent. more coal than the Britannic, the ship was an obvious commercial success. The spirited policy which brought her into existence was appreciated by the public, and the other lines had to move forward. Then followed a period of rivalry, the Cunard Company building the Gallia and Servia, the Inman Company the City of Rome, and the Guion Line the Alaska, all of which were completed in 1881, and afterward the Oregon for the Guion Line--1883--the Aurania the same year for the Cunard Company, and, later still, the America for the National Line, and the Umbria and Etruria for the Cunard Company in 1885.

Since the completion of the Etruria, for various reasons there has been a pause in the tremendous strides made since 1879, and we may briefly review the results. Taking the Britannic as a standard with her ten years' average of 8¼ days across, and her quickest passage of 7 days 10 hours 53 seconds, we have now the following steamers of higher speeds. Taking them in the order of their absolutely fastest passage out or home, they stand thus:

TABLE I.

---+-------------------------+------+-------+------ | | Days.| Hours.| Mins. | +------+-------+------ 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 ---+-------------------------+------+-------+------

It will thus be seen that from the 15 days' passage or thereabout, of the earliest Atlantic steamers, we had got down in the days of the Scotia to about 9 days; in the Britannic to 8¼ days, and, at the present time, we have got to 6¼ days, with seven ships afloat that have done the passage under seven days, and capable of making their average passages range between 6½ and 7¼ days.

Ranged in order of gross tonnage, these eight vessels stand as follows:

TABLE II.

1. City of Rome. 8,144 2. Oregon. 7,375 3. Aurania. 7,269 4. Servia. 7,212 5. Umbria. 7,129 6. Etruria. 7,100 7. Alaska. 6,586 8. America. 5,528

Here the America shows to advantage, for while being eighth in size she is fourth in point of speed, and from what the author can learn, although he had no authenticated details on the subject, he believed she is economical in coal consumption. He might perhaps be permitted to say that one of the most difficult subjects in connection with the propulsion of ships on which to get absolutely accurate data is that of coal consumption. The records of six to eight hours' trials for the purpose of ascertaining the coal consumption are absolutely worthless, as all shipbuilders and engineers know, and so far as English ships are concerned they are never attempted. Foreign owners frequently stipulate for such trials in their contracts with English shipbuilders, and get wonderfully economical results on paper, but the fact that the trials only extend over a few hours renders them valueless, however carefully the coal may be weighed during that period. An authentic record of the absolute quantity of coal consumed, say by each of the eight fastest Atlantic liners, together with their average indicated horse power on the voyage, for a series of voyages, would be extremely valuable.

He gave, in Table III., the consumption per indicated horse power per hour for a number of ships. This table affords valuable data, for it gives, in addition to the dimensions, the moulded draught of water, the midship area, the displacement, the indicated horse power, the speed on trial, the coefficients for the lines both from the block or parallelopipedon, and also from the midship section prism, together with the length and angle of entrance obtained by Kirk's rule, the Admiralty displacement coefficient, together with the coal consumption per day and per indicated horse power per hour.

This table, as will be seen, contains some of the most important of the Atlantic liners, and also a number of other typical ships, which will add a variety to its interest and a value to it. The coefficient, which is contained in the thirteenth column of the table, viz.:

Dis 2/3 × speed³ ------------------------- I.H.P. × sqrt(entrance.) --------------- 10

generally comes out for ships of similar type more nearly a constant in the true sense of the word than the corresponding Admiralty constant. As an example, we have the curves of resistance and horse power for the City of Rome and the Normandie, a large vessel of 6,000 tons, which the Barrow Company built for the Compagnie Generale Transatlantique, in which the coefficient of fineness and the form of the lines pretty closely resemble each other below water; and if we take from the curves the corresponding speeds and horse powers, and work out the constants by the two systems, we have at 14 knots the Admiralty constant for the City of Rome 322.2, and for the Normandie 304.8; and taking for a modified form of constant, the City of Rome gives 253.7 and the Normandie 251.9, which, as will be seen, are much closer together. Similarly, at 15 knots the Admiralty constant for the City of Rome is 310, and for the Normandie 295.2, while a modified constant comes out for the former at 245, and for the latter 244, again agreeing almost identically. The same at 16 knots, for the City of Rome the Admiralty constant comes out 297.6, and for the Normandie 282.8, while a modified constant comes out for the two ships 234.4 and 233.7 respectively, again showing marked agreement. It may be mentioned that in these two ships the engines are of a similar type, being three-crank tandem engines, and the propellers have in both pitch and surface practically the same proportions to the power and speed. The value of these modified constants will probably be found to increase as the speeds increase up to the limit and beyond that point at which wave resistance becomes an important factor.

TABLE III

+--------+---------+---------+-------+-------------+ Name. |Length. | Breadth.| Moulded |Midship|Displacement.| | | | draught.| area. | | | | | | | | | | | | | | | | | | | | ----------------+--------+---------+---------+-------+-------------+ |ft. in. | ft. in. | ft. in. | | | | | | | | | City of Rome | 542 6 | 52 0 | 21 5½ | 1031 | 11,230 | | | | | | | | | | | | | Normandie | 459 4 | 49 11 | 19 9¾ | 892 | 7,975 | | | | | | | Furnessia | 445 0 | 44 6 | 22 2½ | 893 | 8,578 | | | | | | | | | | | | | Arizona | 450 0 | 45 1½ | 18 9 | 758 | 6,415 | | | | | | | | | | | | | Orient | 445 0 | 46 0 | 21 4½ | 904 | 7,770 | | | | | | | | | | | | | Stirling Castle | 420 0 | 50 0 | 22 3 | 990 | 7,600 | | | | | | | | | | | | | Elbe | 420 0 | 44 9 | 20 0 | 807 | 6,350 | | | | | | | Pembroke Castle | 400 0 | 42 0 | 17 0 | 648 | 5,130 | | | | | | | Umbria and | | | | | | Etruria | 500 0 | 57 0 | 22 6 | 1090 | 9,860 | | | | | | | | | | | | | Aurania | 470 0 | 57 0 | 20 0 | 1020 | 8,800 | | | | | | | | | | | | | America | 441 8 | 51 3 | ----- | --- | 6,500 | | | | | | | | | | | | | Oregon | 501 0 | 54 2 | 23 8 | 1150 | 11,000 | | | | | | | | | | | | | Servia | 515 0 | 52 0 | 23 3½ | 1046 | 10,960 | | | | | | | Scotia, P.S. | 369 0 | 47 6 | 19 9 | 867 | 6,000 | | | | | | | | | | | | | Alaska | 500 0 | 50 0 | 21 0 | 949 | 9,210 | | | | | | | | | | | | | Aller | 438 0 | 48 0 | 21 0 | 907 | 7,447 | | | | | | | | | | | | | | | | | | | Ems | 430 0 | 46 10 | 20 7½ | 877 | 7,030 | ----------------+--------+---------+---------+-------+-------------+