Excerpt – Pages 110 – 116
Use of Anthracite Coal in Locomotives.
At the monthly meeting of the Franklin Institute, held June 17th, 1847, the following remarks on the use of Anthracite in Locomotives, were made by Professor W. R. Johnson.
Since the attainment of so complete a success, in using anthracite under the boilers of stationary engines, and on board of all our principal river and sound steam vessels, on the Atlantic coast, it has become a subject of much inquiry, to determine why so little success has attended the efforts to introduce it into general use upon railroads. Various trials, on the Columbia Road, and others on the Reading Road, have, it is understood, been attended with so little promise of advantage, as to cause, at present, the abandonment of that fuel, and an adherence to wood, as the only available material. The cost of wood, alone, to the Reading Railroad, during the last year, is put down, in the late annual report, at $202,061, and, as the total quantity of coal brought to market, over the road, was 1,188,258 gross tons, we have., after deducting the wood required for passenger and freight trains, an expense of $191,569, for the wood required to haul that quantity of coal 94 miles, and to take back the empty cars. It is true, that the whole of this coal did not reach tide-water, but the computation is based upon the fact, stated in the report of the Company, that the cost of wood, “per round trip of 188 miles," to haul 360 tons of coal, the above distance, and “back with empty cars," was 14.92 cords, costing $58.04. It is estimated, by the President of the Railroad Company, that the introduction of anthracite, instead of wood, would save the company $125,000 per annum. Should it save half this sum, it is evident that great outlays, to effect the purpose, would be warranted, and, consequently, the efforts heretofore made would be fully justified. Mr. Nichols, the engineer, and general superintendent of the Reading Road, has been, for some time, engaged in an effort to accomplish this object, by placing the engine and boiler on separate carriages, with a view to an enlargement of the fire surface of the latter. Mr. N. has, in fact, used an ordinary locomotive, to which he has attached, on a separate truck, a boiler, 16 feet long, and 4-1/2 feet wide, with a semi-cylindrical arch running the whole length. This is connected, by jointed pipes, with the engine. The blast is created by a fan, driven by a small engine. The escape steam is thrown into what was the original boiler of the locomotive engine, which is still retained, for the double purpose of serving as a condenser, and of making weight on the driving wheels. If this plan of condensation shall be found available, much time will be saved which is now consumed at water stations, as a large portion of the water will be constantly circulating.
So important to the Reading Railroad, has this item of expenditure of fuel become, that, during the past year efforts have been made by the company to manufacture an artificial fuel, with a basis of anthracite, as a substitute for wood. In this, they are understood to have so far succeeded, as to have made some trips with it. But still the desideratum is the use of anthracite alone.
Having several times, within seven or eight years, witnessed the exclusive use of anthracite, in all the locomotives on the Beaver Meadow, and Hazleton Railroads, making round trips of thirty or forty miles, I have felt much interest in tracing the causes of ill success elsewhere.
From all the inquiries which I have been able to make, the following appear to be regarded as the chief impediments to the use of anthracite in locomotives.
1. The want of rapid ignition, and free, lively combustion.
2. The intense, concentrated, local heat, which is said to destroy the grate bars, to attack the rivets and laps of the fire box, and even to cause blisters to rise in the plates of which it is composed; and, finally, to fuse the ashes into a troublesome clinker.
3. The sharp, angular particles of coal, projected by the violent, fitful blast of the escape-steam, obliquely into the ends of copper tubes, cuts them away within a few inches of the fire end. In the upper range of tubes, it is the upper side which is chiefly attacked, and, as might be anticipated, in the lower ranges, the lower sides are most worn away. The effect of this cutting is usually limited to four or six inches or the length of the tubes.
4. The difficulty of fitting in iron tubes, so as to make perfect joints, and, at the same time, avoid irregularity in the form of the heads, and loosening one tube while another is fastened.
As the first of the above difficulties, the want of proper activity in the fire, has been completely overcome in our steamboats., by the use of a steady fan blast, it seems that an equivalent blast in the locomotive ought to produce the same effect. The irregular, fitful current, generated by the waste steam, is not in all respects an equivalent to the blast of a fan, but when that blast is equalized, by projecting the escape steam, first into a receptacle of considerable magnitude, and then through a number of small pipes, equally distributed over the area of the chimney, the blast is so nearly equable, as to answer completely the purpose of sustaining the fire in brisk and uniform activity. This method of disposing of the escaping steam, originally invented by Mr. Gurney, and applied in common road engines, to prevent the frightening of horses, by the sudden, violent belching sound, was first introduced here by Mr. Hopkins (sic) Thomas, now of Beaver Meadow, while a workman in the employ of Messrs. Eastwick & Harrison. His object was a steady blast, not the mere avoidance of disagreeable noise.
The steam box used to equalize the draught, is cylindrical, 12 inches in diameter, and11 inches deep; two tubes, each three inches in diameter, flanched at the opposite ends to the steam chests of the two cylinders of the locomotive, support the box in the interior of the dust chamber, and convey the escape steam to its centre. A lid, ground to fit the top of the steam box, has 18 jet pipes, rising two or three inches from its upper surface, drawn in at the top to a diameter of half an inch. These are placed just beneath the base of the chimney, and their purpose is to distribute the escaping steam throughout the chimney, and, by limiting, to some extent, the rapidity of flow, to maintain within the box a pressure approaching to uniformity.
Messrs. Eastwick & Harrison founded, on a division of the receptacle into two parts, a patent, which they applied in some engines built by themselves. But as this evidently tended to make the action of the steam upon the air of the chimney, in a degree partial and fitful again, the Beaver Meadow and Hazleton Companies discarded this modification of Gurney’s plan, and in all their engines, which have constantly used anthracite for the last eight or nine years, the draught is ample, the combustion regular, and the evaporation vigorous and well sustained. The fire is, of course, kindled with wood, and when this is well ignited, anthracite is added by little at a time, usually not more than a single shovel full, and in lumps., commonly not above six inches in diameter. If larger than this, they would remain too long in mass, dark and ineffectual; if small egg or nut coal alone were used, it would, it is alleged, by the jarring of the locomotive, spread over the whole fire at once, and check the evaporation. While under way, the bed of coal upon the grate is kept at a thickness of five, or at most, six inches. When fresh coal is added, care is taken, that a single shovel full only is put on at once, and that this is thrown on the part which appears thinnest. Much experience in watching the indications of a manometre, while generating steam by anthracite, enables me fully to appreciate the importance of these practical precautions. In some of the attempts to use anthracite on the Reading Railroad, a bed of I18 inches thick is said to have been allowed to accumulate on the grate. In such cases, the whole engine is said to have become excessively overheated, and a flame to have passed out at the chimney. This is easily understood, when we consider that, in passing through so thick a mass of hot coal, the carbonic acid at first formed, (CO2) by taking up a second proportional of carbon, becomes CO + CO, or two proportionals of carbonic oxide. The atmospheric air to ignite this compound, gains admittance partly through the chinks of the fire door, and the dust box door, and is partly found near the chimney top, where the intermitting blast through a single jet pipe, keeps the chimney alternately receiving and emitting air.
The second evil, that resulting from the highly concentrated heat, has been found much more serious than the preceding. Grate bars were burned out in a few weeks. Capt. A. H. Vancleve, who had charge of the Beaver Meadow Road, states that, at one period, wrought iron bars were substituted for cast, but that it required two smiths' fires to be in constant employ, to make grate bars for four locomotive engines. The secret of preventing this occurrence, was stated by a gentleman at Hazleton, to have been discovered by accident. A boulder, which had rolled from a slope upon the track of the railroad, tore off the ash box of the first engine which passed. As the damage did not interfere with the running of the engine, and as it was not convenient, for some days, to return to the machine shop, it was permitted to continue its trips for some days, without an ash box. The over-heating and wasting of grate bars were so manifestly obviated during the time, as to attract immediate attention. Ash boxes were successively removed from other engines, and, from the adoption of this alteration to the present time, the destruction of grate bars has ceased to be a source of serious inconvenience. A set in the locomotive Franklin, were put in in June, 1846, and were in use, and in good order, at the end of May, 1847.
It might be supposed that the wooden superstructure of the road, and particularly that of bridges, would be endangered by the constant falling of sparks. In the main, it maybe said, that this evil at length cures itself, for both road and bridges, except the rails, become covered with a stratum of cinder, and fine particles of coal, which effectually defends all beneath from danger of igniting by particles of hot matter from the grate. Unlike particles of ignited charcoal, these are, from their very weight, not liable to be easily raised and blown about, by the currents of air created by the cars, which pass over them after they reach the road. Hence the only precaution which has been found necessary, is to place two sheets of iron, one on each side of the bottom of the fire box, extending downwards about nine inches, and sloping inwards, to confine the falling cinders to the central part of the track. At first a watch was established at the bridges, but when the roadway became covered with cinder, there was found to be very little danger from this source. The Hazleton and Beaver Meadow Roads have wooden rails, laid with flat iron bars; where edge or T rails are used, the danger would be manifestly less than in the case of these roads, which have so long used anthracite without detriment.
The concentrated heat of anthracite fires, generally affects injuriously only the laps and rivets of the fire box, unless the iron of that part of the boiler be of inferior quality. Hence the importance of selecting the very best of iron for the fire box, and the probable utility, as suggested by Capt. Vancleve, of subjecting it to a high temperature before using any plate for this purpose, in order to detect blisters of imperfect welding, if such exist in the interior. The number of pieces used in the lower part of a fire box, ought to be the least possible, and the horizontal laps ought not to have their edges presented downwards to the action of the rising flame. I see no practical difficulty in the way of rolling sheets 18 inches wide, long enough to form the. entire circuit of the lower part of afire box. Above that height there would be no danger from this peculiar action of the fire. Nor do I know of any serious objection to welding together the ends of such a sheet, especially if made three-eighths of an inch, or more, in thickness, and thus forming a band in which not a single joint or rivet should come in contact with the fire. All other parts of the boiler would still be made in the ordinary manner.
The locomotive Lehigh commenced running on the Hazleton Road in 1838. In 1844 it was found necessary to renew a space of about 18 inches, in the lower part of the fire box, and this is the only repair which that part has undergone since the engine was put upon the road. I examined it in the latter part of May, 1847, and found the iron, to all appearance, sound and good, with no leaks at the rivets, or elsewhere. Three or four of the upper rows of tubes in this engine, have been in use since 1839, and the rest were renewed about two years ago.
To avoid the conversion of ashes into clinker, those anthracites should be selected, which are free from slaty plies, and which contain the least of sulphuret of iron, or other fusible impurities. Should any inconvenience be found from clinker on a prolonged trip, it could easily be removed at a watering station, by means of a forked fire hook, adapted to that peculiar service. A small supply of wood may be carried, for re-kindling, in case of unusual delays. But the experienced fireman will always be careful to clear coal and clinker from his grate, before he attempts a renewal with wood.* Grates may be hinged, with a view to the prompt discharge of their contents, and, with that facility, the rekindling with wood may. take place even without stopping the engine, especially if advantage be taken of a favorable grade of the road.
*This, and the succeeding precaution, are suggested by Capt. Vancleve.
The third point of difficulty, that resulting from the cutting away of copper tubes, is fully obviated by the substitution of iron, with the farther advantage of economy in the first cost. But this brings us to the fourth and last difficulty-that of securing iron tubes to the heads of the boiler.
This has been attempted in several different ways. One consists in cutting a screw at each end of the tube, to enter corresponding threads cut in the heads of the boiler, and then riveting over the projecting edges of the tubes. That on which Mr. Baldwin has founded a patent, consists in brazing a short piece of copper tube to each end of the iron one, and then connecting the former with the head of the boiler, in the same manner as he puts in copper tubes. But that which seems the most simple, and which is quite effectual, as proved at Beaver Meadow and Hazleton, for a course of years, is the turning off of the iron tubes, on the outside, at each end, in the form of the frustrum, of a cone, to the distance of seven-tenths or an inch, by which the thickness of the tube at the extremity is reduced about one-half. This conical part receives a ring of copper, cylindrical within, conical without, and about half an inch wide, Which, after the iron tube has been inserted in its place, is driven on to its conical termination, filling the space between it and the edge of the aperture in the head of the boiler. This copper ring, by its wedging effect, tightens the iron tube, forms a close joint, and allows the edge of the iron tube to be slightly opened out, and riveted, to form a very perfect juncture. The language used in describing the result of this mode of fitting in the tubes, was, that the “joints never leaked a drop." In rare instances, the welding of a tube, (made by the same process as gas tubes is found slightly defective, but this does not long put a stop to the use of the engine, for a very little labor suffices to tap a screw in each end, and plug up a single defective tube, till a convenient opportunity occurs for its removal. To clear dust of anthracite from the tubes, a species of screw anger, with a sharp edge, like that of a chisel, is occasionally employed.
The quantity of anthracite commonly used in a round trip of 30 miles, on the Hazleton Road, is from a ton to a ton and a half, hauling 35 to 40 cars, and conveying from 100 to 120 tons of coal. The grades on this road are heavy, - 60, 80, and 140 feet per mile,- all in the direction of the trade. The severest labor is, consequently, encountered, in taking back the empty trains. In two experiments, conducted by Capt. Vancleve, over the Beaver Meadow Road, reducing its grades by Pambour's formula. to the condition of a level, he found that the seven ton engine required 1-1/2 pounds of anthracite per ton, per mile of freight and cars hauled, and the 13 ton engine took but one pound, for the same labor. The small engine was subject to slipping of its wheels, on the high grades, which, of course, impaired the efficiency of its fuel.
Those who are most familiar with this subject, attribute to the early, persevering, and well directed efforts of the Hon. Samuel D. Ingham, formerly President of the Beaver Meadow Railroad Company, much of the credit of urging on to final success, the experiments which have proved so important to the interests of that coal region.
Rev. July 2010