Bibliography-Craddock, Chemistry of the Steam Engine; Clark, Railway Machinery); Farney, Catechism of the Locomotive); Halsey, Locomotive Link Motion'; Hughes, Construction of a Locomotive'; Meyer, Locomotive Construction' (1885); Norris, 'Handbook of the Locomotive (1852); Sinclair, Engine Running and Management.'

FRED H. COLVIN, M. E., Author, American Compound Locomotives.) Locomotive, Coaling of the Modern. The modern locomotive coaling plant is the product of three primary requirements, namely, reduction in cost of handling the coal; reduction of waste; and saving of time to locomotives at busy terminals and to fast trains on the line.

Twenty-five or 30 years ago it was said that there was probably no work on American railroads which was done in such a variety of ways as that of handling and supplying coal to locootives. Nearly every road had its own par

ticular method of doing it, which was usually determined by circumstances, tradition or perhaps prejudice. The importance of using improved methods of handling to enable some more accurate account of the fuel consumption of each locomotive to be kept, and to reduce the cost of handling, was coming to be generally recognized, however. Railroads running through mining districts were regarded as having a great advantage in this respect, as they could have their locomotives coaled direct from the mine chutes, thus minimizing the cost of handling, and at the same time enabling an accurate record of the amounts of coal taken to be kept, as the chute pockets were of known capacity. The best general practice at that time for the larger points was to take the coal from platforms alongside the track, which varied in dimensions and therefore in storage capacity, the figures for the latter ranging from 50 to 1,800 tons. Drop-bottom buckets holding from 1,000 to 2,000 lbs. and filled by shoveling, were lifted by derrick or crane, and their contents discharged into the tender. The larger platforms had a narrow-gage track and a truck on which the buckets were moved to the cranes. The coal had to be handled a number of times, as it was first shoveled from the cars to the platforms, again to the buckets, then moved by hand to the crane, hoisted by hand with the latter and finally dumped into the tender.

But the rapid growth of railroad transportation required that the coal be delivered to the locomotives more quickly and with a reasonable degree of economy, and a variety of devices of greater or less merit resulted. An early form used on the Philadelphia, Wilmington and Baltimore, now a part of the Pennsylvania, consisted of an inclined track alongside the main line, at the top of which was a shed with pockets for storing the coal. Small iron cars ran on narrow-gage tracks on each side, but at a lower level than the track on which the coal was received. A bridge ran across above and at right angles to the main-line tracks, the narrow-gage cars being run out on this bridge and dumped through suitable openings and chutes into the tenders below. It cost the road only one-fourth as much to handle its coal in this way as by previous methods (presumably buckets and cranes), not counting the great in two and one-half minutes. But the principle saving in time, engines being able to take coal toward which the best general practice tended, where the amount of coal handled justified it, was to provide storage for coal in bulk, defrom pockets which were at a sufficient elelivering it to engines by weight or measure vation to discharge to the tenders by gravity. The Baltimore & Ohio was one of the first to use this form, having it arranged to take coal on either side. The coal-receiving track was about 35 feet above the ground, and 11 or 12 feet below it was a platform about 20 feet wide, on which the coal was dumped. On each side of the platforms were bins 10 or 12 feet wide at the top, with bottoms inclined at about 60 deg. from the horizontal. At the lower end of each bin was an apron held up by counterbalance weights when not in use, but dropped down to about the angle of the bin bottom when the bin was emptied. Four strips were nailed around the inside of each bin to denote

the amount of coal contained, the levels of these strips indicating 11⁄2, 2, 21⁄2 and 3 tons respectively. Engines were charged with the amount of coal taken, each bin being numbered. The platform and bins were not roofed over, leaving the coal exposed to the elements.

In 1885 a committee of the Roadmasters' Association investigated the costs of handling coal by the different methods in use. For handling over platforms of different constructions the maximum was 30 cents a ton and the minimum II cents, with an average 19.4 cents. For coal chutes the maximum was 9 cents a ton and the minimum 4.5 cents, the average being 7.4 cents. The average saving in favor of the chutes was therefore 12 cents a ton. The time consumed in taking coal from the chutes was one minute, and from other devices 12 minutes a saving of 11 minutes per engine coaled in favor of the chutes. Where 3,000 tons were handled monthly there was a saving in favor of the chutes of nearly $4,500.

Improvements in chutes continued, the effort being to obtain a form that could be worked easily by one man, would have few parts in its construction and could be repaired at small cost. A chief objection to the earlier forms was that the combination of pulleys, chains and balance weights was such as to cause the aprons to close with considerable momentum, racking the entire mechanism and disarranging the working parts. A change to overcome this consisted in pivoting the apron so as to be self-balancing, discarding the chains and weights. This, however, threw a considerably increased weight and strain on these pivots; also the sides of the apron were liable to be pushed out unless supported. Furthermore, the top of the apron had to be locked to prevent its being blown open by a heavy wind. In 1891 the Susemihl chute was introduced on the Michigan Central. Chains and weights were used but they were so adjusted that "the outward pull of the top of the apron due to its vertical thrust beyond the pivot was taken exactly for each position of the apron.» Among other advantages, no latches were needed, the inner door being kept closed by the apron as it was lowered, by means of small segmental castings attached to the lower edge of the inner door, over which the lower edge of the apron rose as it descended. Very little iron was used in these chutes, the total cost of iron being only about $5. The total cost of the structure was said to be much less per pocket than any form then in use by the railroads.

Other designs of chutes with balanced aprons were shortly introduced, the object in each case being to have the vertical resultant of the counterweight vary the same as the weight of the apron. In the Williams, White & Company design the apron arm had fastened to its outer end cast-iron blocks which could be moved forward or back to adjust the proper balance. A small latch at the top held the apron and was pulled by the fireman when he wanted to take coal. The arm of the apron, in rising, came in contact with a latch which released the inner, or coal, door.

The modern method of lifting and transferring the coal by conveyors at locomotive coaling stations was first used in isolated cases

in the early nineties. One of these plants was installed by the National Docks Railway of Jersey City, N. J., for the joint purpose of coaling locomotives and supplying a boiler house. The coaling track was also the coal supply track. The pit beneath the track had an inclined bottom which slid the coal sideways into an underground pit opposite the centre of the structure. The "endless bucket elevator," as it was called, lifted the coal 39 feet and discharged it into bins at the top, the storage capacity being 200 tons. The elevator was driven by an 8-h. p. vertical engine, had 9 inch x 12 inch buckets spaced 12 inches apart, and had a capacity of 85 tons an hour.

As the demand for saving of labor and expense in the handling of fuel for heavy-draft and high-speed locomotives continued, the method referred to in the preceding paragraph was developed and perfected until at the present time the more complete of such plants are not only automatic in operation, reducing labor cost to a minimum, but the coal, which is stored in large quantities is also accurately weighed as it is withdrawn from the pocket, and the weight of the draft automatically registered and printed in triplicate. Also, many of these plants combine with them ash and sand handling facilities, so that a locomotive may have the operations of taking coal and sand and dumping ashes performed without moving, and almost simultaneously. In some cases the standpipe is so situated that water also may be taken without change of position. One of the best examples of a station of this sort was built for the Terminal Railroad Association of Saint Louis prior to the opening of the World's Fair, to enable a large number of locomotives to be cleaned, coaled, watered and sanded at one time. The station was built by the Link-Belt Machinery Company of Chicago. It has a storage capacity of 1,000 tons and is so arranged that seven locomotives can take coal, sand, water and discharge ashes at one time, and 21 locomotives may be cleaned simultaneously. The average number of locomotives handled daily is about 200. Tributary to the 1,000-ton pocket, which is 80 feet long, are 13 auxiliary pockets, each with a capacity of 15 tons and mounted on registering beam scales. There are six of these pockets on each side of the structure and one at the left-hand end. Running between these pockets, and swung from the girders above, is a walk for the scale-tender, who keeps the auxiliary pockets filled, the scale beams being an index to their condition at all times.

Coal is received on two separate tracks and is elevated to the storage pocket by a double system of Link-Belt carriers having a combined capacity of 2,000 tons in ten hours. The arrangement is such that either system may be put out of commission without interfering with the other. Electricity is used throughout for motive power. The loaded coal cars are drawn over the track hoppers and the empty cars removed by a double car-puller, shown in the drawings, having a capacity of eight loaded cars. Each cinder pit will accommodate three locomotives. Where there are a number of locomotives on one track awaiting the service of the station, the first one can take coal, sand and water simultaneously, requiring about four

minutes if a full tank of water is needed. It can then move up to be cleaned, a second locomotive take its place under the station and a third move upon the pit, enabling all three to be cleaned at one time. The station will serve engines headed either way. An independent carrier receives the cinders from the track pits and deposits them in an overhead bin which discharges into a car on one of the coal tracks.

In this same track is a hopper for green sand, which is elevated by a carrier to two overhead circular steel tanks having a capacity of 125 cubic yards each. Each tank discharges into a dryer immediately beneath, the pipe from which passes up through the centre of the tank and assists in drying the adjacent sand. From the dryers the sand is again raised by carrier to the top of the structure and discharged by gravity into two storage bins of 85,000 lbs. capacity each, one being on each side of the station, midway of the tracks. The gravel and other refuse from the sand is discharged into the cinder bin. Water is delivered to the locomotives from two cylindrical tanks above the scale pockets, holding 20,000 gals. each. These tanks are connected to the city mains.

It will be noted that this station is built entirely of steel above the foundations, and covered with galvanized iron. This is not usual practice, timber commonly being used in these structures. Although the steel construction is somewhat more expensive in first cost, the combination of strength and lightness, the greater durability, the immunity from fire and the more pleasing appearance easily justify the additional expense. Several costly stations built of timber have been destroyed by fire and have entailed annoying difficulties and delays until they could be replaced.

The most recent practice is tending away from the combination of the ash-handling and coaling facilities in one plant, it being found more satisfactory in many cases to isolate the ash-handling plant. In a recent example of up-to-date locomotive coaling, sanding and ash-handling facilities, that of the Pittsburg & Lake Erie at McKees Rocks, the three plants are separate units.

The ability to weigh or measure the coal taken by each engine is regarded as highly important on some roads. If the tender is coaled from buckets or barrows, keeping record of the amount is a simple matter. Marking the insides of pockets to indicate given quantities of coal is another method. For weighing all of the coal in a large storage pocket there are two schemes. One of these is the McHenry dynamometer method. The bin or pocket rests on the top plate of a small chamber filled with a fluid which transmits the pressure through a small pipe to conveniently located pressure gages. By the other method the entire pocket is supported on scales, as in the Saint Louis station described above.

In regard to cost, a committee of the American Railway Master Mechanics' Association, reporting in 1901, expressed the opinion that the expense of coaling locomotives is governed entirely by the kind of cars in which the coal is carried, without reference to the kind of plant in which it is handled, provided the plant is one that will admit of dumping the coal VOL. 13-3

either to bin or conveyor. If the coal is received in hopper-bottom or side-dump cars, the cost will probably be between one and three cents a ton delivered on the tender, no matter whether the cars are pushed up on an incline and dumped into pockets, or whether a system of conveyors is used. If the coal is received in gondola or box cars and has to be shoveled from the car, the cost will be from six to eight cents a ton delivered to the tender, regardless of the kind of coaling station through which it is handled. The majority of mechanical men replying to a circular of inquiry of a Master Mechanics' committee two or three years ago appeared to prefer the inclined-track coal chute where there is sufficient space.

In 1902 a committee of the American Railway Engineering and Maintenance of Way Association considered carefully the question of coaling stations. A list of the principal factors to be considered in adopting a method was given in that report as follows:

1. The question of location is one of the most important for consideration. This will be governed by the convenience as to the operation of the business of the railroad. At terminals and at junction points, it is probable that large coaling plants will be desired; supplied to locomotives hauling freight and passenger but at intermediate points on the line coal must be

trains. The location may determine largely the nature of the plant to be used. Where large quantities of fuel for the construction of tracks and buildings, an exare to be handled with only a limited amount of room pensive mechanical plant may be fully justified. At other points where land values are small, a totally different style of plant may be the most economical.

2. The quantity of coal to be handled will also largely influence the character of the plant to be one or two carloads of coal per built. Where but day are required, it is doubtful whether anything but the simplest plant should be built that is sufficient to permit delivering the coal required in the least On the other hand, where from 200 possible time. to 400 tons per day have to be handled, expensive plants, well designed machinery and first-class construction will be justified.

3. A third consideration is the cost of operation. This touches upon the labor question, involving the consideration whether steam engineers, machinists and expert mechanics, or crude day labor shall be utilized In some in connection with the operation of the plant. parts of the country day labor may be had at approx. imately one-half the rates which are demanded in others. The rate of wages to be paid to the laborer will be an important item.

4. A fourth consideration will be the amount of first cost, and also the cost of repairs and renewals. It is evident that to make a true comparison of the economy of different plants, these items should be reduced to a measure of cents per ton of coal handled,

rather than to make a comparison of the gross amounts of actual cost and maintenance.

5. In the same connection, a true comparison will require a consideration of the interest on the cost of the investment, and this also should be reduced to an equivalent value of cents per ton of coal handled.

6. Complicating all of the above is the question of storage. That is a matter of great importance, and that it usually receives but little consideration, is evident from the amounts which are annually spent in cars and holding the same storing coal on coal

on

side-tracks at coaling stations, rather than constructing

suitable storage bins in which the coal may be kept, thus liberating the cars for commercial business.

7. The kind of coal handled will also influence the decision -- whether it be anthracite or bituminous, or both, inasmuch as the appliances which are efficient for one kind of coal may be less so for the others.

8. The facilities which each company has for deliv ering coal to its coaling plants will tend to make the situation more involved, since coal may be handled either in box cars, gondola cars (with stationary or with movable sides or traps), side-dumping or bottomdumping cars, and other varieties, each of which will have its own influence on the special modification of plant to be adopted for economy.

CHARLES H. FRY, Associate Editor Railroad Gazette; Chicago.

Locomotive, Design and Construction of the Modern. The various problems involved in the work of designing and constructing a modern, first-class locomotive are both many and complex. In the matter of design, the problems presented by such considerations as cylinders and wheel arrangements, are simple as compared to those relating to boiler power. It is evident that nothing can be gained by employing a large cylinder capacity unless a sufficient supply of steam can be maintained under all of the circumstances liable to be developed under normal working conditions. Therefore, the development of any one type more powerful than another can only be accomplished principally by an increase of gratearea and boiler-capacity.

In this respect, the foreign designers have been badly hampered by the limited character, of the loading gauge; but, the limitations governing the matter of dimensions have always been much more liberal in America, so that in the matter of boiler design, American practice has not only reached a stage far ahead of that of any other country, but has also resulted in the replacement of the "American" type of locomotives universally employed on the American railroads prior to 1890, by much larger machines which are capable of developing more than double the amount of tractive power.

In considering the process which goes on within the fire-box of a locomotive, it is found that under favorable conditions, each pound of coal consumed will sustain one indicated horsepower for a period of about fourteen minutes, and that within certain limits the power developed is nearly proportional to the coal consumed. Therefore, in the development of the modern locomotive, the grate-area has been increased and the heating surface extended, thus enabling the burning of a larger amount of fuel, and consequently the maintenance of a larger supply of steam. On the other hand, although the American designer has not been restricted in the matter of dimensions, he has not been able to increase the working capacity of the fireman, so that after all, the power of the modern locomotive has not increased in proportion to its dimensions.

Under the most favorable conditions, a locomotive fireman will handle about 6,000 pounds of coal per hour, a rate which will serve to develop about 1,200 indicated horse-power. At short intervals this amount of power may be increased or out-run the rate of firing, but it fairly represents the maximum amount of power that can be developed under the circumstances, and the further development of the locomotive will depend upon the employment of some form of automatic stoker, which although guided in its operations by a man, will not represent the strength of only a single

man.

The considerations relative to grate-areas and fire-boxes naturally lead to the question as to the practicability of obtaining better results by employing other forms of boilers than those in common use. Boilers with cylindrical corrugated fire-boxes such as the Vanderbilt boilers, were first applied to locomotives in the United States. The principal advantages claimed for this type of fire-box are: (1) a free water circulating area; (2) simplicity of construction;

and (3) the elimination of screwed-stays and a copper fire-box. These advantages appear to have been realized in practice, and although boilers of this type are extensively used in this country, their employment in foreign locomotives has not been carried very much farther than a few experimental applications.

The water-tube boilers are another type which promote considerable speculation in this connection on account of their extensive adoption in the stationary and marine service. Many designs of water-tube boilers for locomotives have been proposed, but examples of their successful practical application are still lacking. The principal difficulty of applying a boiler of this type to a locomotive lies in the circumstance that the shell of the ordinary boiler serves as a part of the framework of the locomotive, and as it is not much heavier than the best water-tube boiler of the same capacity, it is impossible to abandon it without materially increasing the weight of the frame.

Besides the matter of the restricted gratearea already considered, another limitation which affected the earlier types of locomotives was that which related to their tractive power. The pull of a locomotive at the draw-bar depends upon its speed. At slow speed the maximum pull is limited by the adhesion or coefficient of friction between the wheels and the rails. After the speed has reached a point at which adhesion is sufficient to permit of the development of full power, the pull is inversely proportional to the speed. In a locomotive developing 1,200 horse-power, the pull at the speed of 25 miles an hour is about 22,000 pounds, and at 80 miles an hour, about 7,000 pounds. The latter amount, however, is still further reduced in actual practice by the usual loss of power between the cylinder and the draw-bar, so that the maximum pull of an engine running at a speed of 80 miles an hour is equal to about 5,000 pounds. On the other hand, in considering the tractive effort at starting, and assuming that the adhesion is equal to about one-fifth of the weight on the drivers, it is noted that the American type of locomotive built prior to 1890, carried a weight ranging from 14,000 to 16,000 pounds on each driver, and exerted at starting, a tractive effort which ranged from 10,000 to 12,000 pounds. It is noteworthy in this connection, that the wheel loads of the modern locomotives have been increased to such an extent that they are capable of developing a tractive force at starting equal to 5,000 pounds per driver, or a maximum of 20,000 pounds for the "American" type of locomotive.

It is also interesting to note, that even this amount is exceeded by the latest type of locomotive placed in service by the Pennsylvania Railroad Company, to haul their 18-hour trains between the cities of New York and Chicago. With the exception of the valve-gear connections, this locomotive is built on lines very similar to those of the "Atlantic" type of express locomotives. It is a simple engine having two outside cylinders 22 inches in diameter with 26 inches stroke, which are connected to fourcoupled driving wheels of 80 inches diameter. Under a working boiler pressure of 205 pounds to the square inch, the maximum tractive effort at starting is equal to 25,800 pounds.