The Development of the Anthracite-Burning Locomotive
By Paul T. Warner
Railroad & Locomotive Historical Society Bulletin, Vol. 52 pp 11 – 28.
Ed. Illustrations added by J. McVey
During the latter part of the eighteenth century, the pioneers living in certain sections of eastern Pennsylvania became much interested in peculiar mineral known as "stone coal" or "black stone". As early as 1768 it was known that it had combustible properties; but owing to the difficulty in igniting it, the abundant supply of wood fuel available, and the poor transportation facilities of that time, its use spread slowly. Records indicate that it was being used for blacksmithing in 1769, and that deposits were located near Mauch Chunk in 1791. In 1803 a load of stone coal was taken to Philadelphia, and attempts were made to burn it in the boiler of a steam engine at the water works; but as the fire was extinguished in consequence, the coal was broken up and scattered over the sidewalks in place of gravel.
Stone coal--now known as anthracite, or hard coal--was first placed in the market in 1807, when a certain Abijah Smith loaded 50 tons of it in an "ark" at Plymouth, near Wilkes‑Barre, and floated it down the Susquehanna to Columbia, Lancaster County, where he tried to sell it; but there were no buyers. In the following year, one Jesse Fell made the experiment of burning stone coal in the fire place in his home, and reported that "it made a clearer and better fire, at less expense, than burning wood in the common way."
Anthracite was first mined by the use of powder in 1818, and thereafter its production rapidly increased. In that year the Lehigh Navigation Company was organized, and the coal was soon being regularly floated down river to Philadelphia in unwieldy boxes called "arks", which were steered by long oars or sweeps. As it was difficult to get the arks back, they were demolished after being unloaded, the lumber was sold and the iron‑work returned overland to Mauch Chunk, a distance of 80 miles. By the time the first railroads were in operation the value of hard coal as fuel was fully recognized, and one of Pennsylvania's greatest industries had become firmly established.
Anthracite is the densest, hardest and most lustrous of all coals, and its combustible content consists almost entirely of carbon. It burns with very little flame, and with practically no smoke. In contrast, a true bituminous coal contains a relatively large amount of so‑called volatile matter which, on the application of heat, is driven off in the form of a gas. The principal constituents of this gas are hydrogen and carbon, and if the temperature is not sufficiently high, and the air supply is inadequate, the carbon deposits as soot, which forms the principal coloring matter in smoke. In any event the volatile matter burns, not on the grate, but in the space above it. For this reason anthracite is a slower burning fuel than bituminous coal, but the heating values of the two are practically equal. Hence to produce a given amount of steam in a given time we must burn as many pounds of anthracite as of bituminous, but as the former burns more slowly, a far larger grate must be provided on which to consume it. The main problem with which the early designers of hard coal burning locomotives had to contend was that of providing sufficient grate area, and the story of the development of the hard coal burner deals chiefly with the struggle to solve this problem.
The first locomotive used in this country was the Stourbridge Lion, imported from England; and records state that when it was experimentally fired up at New York in June, 1829, Lackawaxen hard coal was used as fuel. It should also be noted that the first railroad to operate commercially in America--the Baltimore and Ohio--burned anthracite in its earliest locomotives. The Tom Thumb, built by Peter Cooper of New York, which made its first successful trip at Baltimore on August 28, 1830, was a hard coal burner. History records that the boiler of this little machine was of the vertical multi‑tubular type, about 20 inches in diameter and five or six feet high. Artificial draft was created by a fan driven by a belt passing around a wooden drum attached to one of the road wheels, and a pulley on the fan shaft. It was the slipping of this belt that caused the first locomotive "steam failure" in this country, on that memorable day when the Tom Thumb was racing a gray horse, attached to another car on a parallel track.
The Stourbridge Lion The Tom Thumb
Ross Winans, in a report made to P. E. Thomas, President of the Company, estimated that the Tom Thumb, while running, developed an average of 1.43 horsepower.
The success of the Tom Thumb convinced the management that it would be advisable to operate the road by steam power, and on January 4, 1831, the Company issued a proposal for the construction of locomotives, which was the first of the kind to be made in the United States. It was agreed that the sum of $4000.00 would he paid for the most approved engine, and $3500.00 for the next best. Among the stipulations included in the agreement were the following:
"The engine must burn coke or coal, and must consume its own smoke."
"The pressure of the steam not to exceed 100 pounds to the square inch; and as a less pressure will be preferred, the company in deciding on the advantages of the several engines will take into consideration their relative degrees of pressure. The company will be at liberty to put the boiler, fire tubes, cylinder, etc., to the test of a pressure of water not exceeding three times the pressure of the steam intended to be worked, without being answerable for any damage the machine may receive in consequence of such test."
"There must be two safety valves, one of which must be completely out of reach or control of the engine man, and neither of which must be fastened down while the engine is working."
"There must be a mercurial gauge affixed to the machine with an index rod showing the steam pressure above 50 pounds per square inch, and constructed to blow out at 120 pounds."
Several locomotives were built in answer to this proposal, but only one --the York -- proved at all satisfactory. This locomotive was built by Messrs. Davis and Gartner, of York, Pennsylvania. It was capable of hauling 15 tons at a speed of 15 miles an hour on level track, and of running at a maximum speed of 30 miles an hour. The cylinders were vertical, as was also the boiler, which had an internal, horizontal water table nicknamed a "cheese", for the purpose of increasing the heating surface. This "cheese" gave trouble by filling up with mud and burning out. Anthracite was used as fuel, and artificial draft was furnished by a fan.
The York was followed by a group of vertical boiler locomotives which were known as either "Grasshoppers" or "Crabs", according to the design of their machinery. The Grasshoppers had vertical cylinders, with vibrating beams which were fulcrumed on top of the boiler; while the Crabs (which were a creation of Ross Winans) had horizontal cylinders. The boilers of all these locomotives were of the multitubular type, burning anthracite and fitted with blowers operated by exhaust steam. The Crabs also had feed‑water heaters, through which the exhaust steam passed before it was discharged into the atmosphere.
In the Seventh Annual Report of the Company, issued in 1833, George Gillingham, Superintendent of Machinery, referred to the Grasshopper Atlantic as having run 13,280 miles, burning 190 tons of coal at $8.00 per ton. This represented an average consumption of 32 pounds per mile.
These vertical boiler curiosities exerted but little influence on the development of the American locomotive, but because of their unusual design, and the fact that they successfully burned anthracite, they are deserving of brief mention.
We now turn to the State of Pennsylvania, where there was under construction a railroad which was destined to play a leading part in the hauling of anthracite and the development of the hard‑coal burning locomotive. This was the Philadelphia and Reading, which was built chiefly for the purpose of transporting coal from the mines in the anthracite region to tidewater on the Delaware River. The line between Reading and Philadelphia was completed in 1839, and the extension to Pottsville was opened in 1842. For practically the entire distance the line had a river grade, either level or slightly descending, from the mines to tidewater. The grades were favorable to the loaded movement, and presented no serious obstacle to the hauling of empties on the return trip.
The first locomotives used by the Reading burned wood, but in 1839 the road placed an order with Messrs. Eastwick and Harrison, of Philadelphia, for a high‑powered freight engine to burn anthracite. This engine, the Gowan and Marx, was one of the most famous locomotives ever built. At the time of its construction, Eastwick and Harrison had acquired an excellent reputation as locomotive builders. This was largely due to the invention, by Joseph Harrison, Jr., of the equalizing beam, patented April 24, 1838, which made it possible to build coupled locomotives that were sufficiently flexible to operate safely on the poorly surfaced tracks of the period. Eastwick and Harrison had built a number of hard‑coal burning locomotives which were operating with a fair degree of success, notably on the Beaver Meadow Railroad.
The Gowan and Marx was of the 4‑4‑0 type, designed to weigh 11 tons, with 9 tons on the drivers. This unusual weight distribution was obtained by placing the firebox over the rear driving axle and using a short boiler barrel and wheel base, thus throwing the center of gravity as far to the rear as possible. The firebox was of the Bury, or hay‑stack pattern, with a grate area probably approximating 12 square feet, which was considered exceptionally large. As in most of the Eastwick and Harrison locomotives, the cylinders were placed at a steep angle, and the pistons were outside‑connected to the rear pair of drivers. The exhaust steam was discharged into two copper chests, or draft boxes, and escaped up the stack through a large number of openings instead of through a single nozzle. The object sought was to create a more even draft on the fire. In May, 1839, the Committee on Science and the Arts of The Franklin Institute had investigated the performance of an Eastwick and Harrison hard‑coal burner. Their report, referring to the draft boxes, stated that "with the aid of this contrivance, the anthracite fire is kept in a state of intense activity, and generates an abundance of steam, without the annoyance and danger arising from the smoke and sparks of a wood fire".
The Gowan & Marx
The locomotive mentioned in this report was operating at Philadelphia, but unfortunately no reference is made to the name of the engine or to the road for which it was built.
The grates of the locomotive just referred to consisted of grooved wrought iron bars, which were protected from the action of the fire by a coating of clay placed within the grooves. The grates of the Gowan and Marx were doubtless constructed in the same way. The latter locomotive was also the first one to be equipped with a blower for stimulating the fire.
On February 20, 1830, the Gowan and Marx startled the railroad world by hauling a train of 104 loaded four‑wheel ears weighing 423 tons from Reading to Philadelphia at an average speed of 9.82 miles an hour. Including the weight of the engine and tender, the total load equalled forty times the weight of the locomotive. A report of this remarkable run was issued by G. A. Nicolls. Superintendent of Transportation of the Railroad Company, under date of February 24, 1840. This report stated that the locomotive consumed 5600 pounds of red ash anthracite, while evaporating 2774 gallons of water. This represented an actual evaporation of 4.13 pounds of water per pound of fuel. It was also stated that "the steam ranged from 80 pounds to 130 pounds per square inch, to which latter pressure the safety valve was screwed down.'' With 130 pounds pressure, the locomotive must have been exceedingly ''slippery". Mr. Nicolls described the engine as having cylinders measuring 12 2/3 by 16 inches, and driving wheels 40 inches in diameter; and he gave the total weight as 24,660 pounds, with 18,260 pounds on drivers.
The Gowan and Marx was a success, and twelve locomotives of similar design were ordered in 1842 from the Locks and Canals Company of Lowell, Massachusetts, and were delivered in 1843; but it was evident that, for reliable service, increased grate area was needed for burning such a refractory fuel as anthracite. Mr. Nicolls tackled the problem, and the result was an amazing creation which was built at the Reading Shops in 1846 and was appropriately named Novelty. The details were worked out by Lewis Kirk, who at that time was Master Mechanic. The engine and boiler of this curiosity were mounted on separate vehicles, the idea being that they could not both he placed on the same set of wheels and made of sufficient capacity. The Novelty. although a courageous venture, proved a complete failure and exerted no influence on locomotive design.
The next step to produce a successful hard‑coal burner was taken by Ross Winans, of Baltimore, ‑who was proving a prolific designer of railroad motive power. In 1847 he built four locomotives of the 0‑8‑0 type for the Reading. The firebox was of the Bury, or hay‑stack pattern, but in order to provide sufficient grate area it had a flat‑sided, rearward extension, rectangular in cross‑section. This construction resulted in a heavy overhang, throwing an excessive amount of weight on the rear wheels. To obviate this, Winans placed a pair of pony wheels under the foot plate and the locomotives were then accepted. They had a grate area of 17.66 square feet, and burned anthracite more successfully than any locomotives previously tried. In spite of the progress made, however, the year 1850 found the great majority of the Reading's locomotives still burning wood.
The next steps in the development of the hard‑coal burner were taken by James Miliholland who, in the late forties, was placed in charge of the Mechanical Department of the Reading. He was an inventive genius and an excellent mechanical engineer; and while he made mistakes, he turned out locomotives which had no superiors at the time of their construction. In a report of Superintendent Nicolls dated December 1, 1851, it is stated that "satisfactory results have been obtained from the application of an improved method of burning anthracite coal in locomotives, invented by James Millholland, Master Machinist, by which the quantity of coal consumed and the intensity of the fire are alike diminished.
''The successful experience of this improvement for several months, in five engines, has established its value, and proved that anthracite coal is, at present prices of wood, the most economical fuel we can use in engines adapted to its combustion.
Quoting further from the same report, we read
''The 'Allegheny' engine has been completely rebuilt, in place of an engine of the same name, whose Boiler had proved defective from age and inferior iron. It has been built with Mr. Millholland's improvement, and has, so far, worked remarkably well."
This "improvement", was doubtless the one mentioned by Angus Sinclair on Page 289 of his book "Development of the Locomotive Engine", where he says, "The furnace was kept within the frame line until it reached the back of the hind drivers, when it was spread, reaching about five inches beyond the rail on each side." Dr. Sinclair states that the first engine so rebuilt was the Baldwin locomotive Warrior, but the Annual Reports of the Philadelphia and Reading Railroad Company indicate that the Warrior was not rebuilt until 1858. However that may be, it is interesting to note that in the Railway Mechanical Engineer of May, 1916, there was illustrated and briefly described a 4‑6‑2 type compound locomotive on the Paris‑Orleans Railway of France, which had a firebox similar in plan to that attributed to Mihiholland by Sinclair.
On February 7, 1852, Millholland took out a patent for a locomotive boiler designed to burn hard coal. This boiler, in modified form, was applied to the freight locomotives of the Pawnee class, built at the Reading shops during that year. These locomotives were of the 2‑6‑0 type, but were not true Moguls, because the leading wheels were placed back of the cylinders arid were held rigidly in the main frames. The boiler had an overhanging firebox with a short combustion chamber, and there was also an intermediate combustion chamber, thus necessitating the use of two groups of tubes. In design and workmanship these locomotives represented the best practice of their day, but they were poor steamers. Millholland, following the ideas of the period, provided his coal‑burners with an assortment of mixing chambers and ingenious gadgets which, while they may have been theoretically desirable, worked poorly in practice.
We must now leave the Reading for a time, and turn our attention to the Delaware, Lackawanna and Western Railroad which, although it was rapidly becoming important as an anthracite carrier, was using wood as locomotive fuel. Like the Erie, this road was originally constructed with a track gauge of six feet. The first hard coal burner built for the Lackawanna was ordered in October 1853, from Danforth. Cooke and Company, of Paterson, New Jersey, and was appropriately named Anthracite. This engine was completed in May, 1851. The design, for which Watts Cooke, subsequently Master Mechanic of the Lackawanna, was largely responsible, closely followed Miliholland's Pawnee class. The wheel arrangement was the same, and the boiler was very similar in construction. The Anthracite, however, in its original form, gave no end of trouble. The locomotive would not operate safely on the crooked tracks of the Lackawanna. until the rigid leading wheels were taken out and a four‑wheeled swiveling truck substituted for them. The locomotive was also a poor steamer. A very intense draft was found necessary, and this pulled the coal through the rear tubes into the intermediate combustion chamber, which rapidly filled up, choking the tubes and causing steam failures. It was necessary to remove the intermediate combustion chamber before the locomotive could be made to steam satisfactorily.
The second hard coal burner used on the Lackawanna was the Carbon, built by the ingenious Ross Winans of Baltimore, and placed on the road in October, 1854. This was a genuine Winans "Camel," and was representative of one of the most unusual types of locomotives ever used in this country. The wheel arrangement was 0‑8‑0, and the boiler had a long overhanging firebox. The crown and roof sheets sloped toward the rear at. a sharp angle, and there was practically no steam space above the crown. The grates were of cast iron, arranged so that each bar could be shaken independently of the others. In addition to the firedoors at the rear, there were two ''chutes'' on top, through which coal could be dumped on the grates. A huge dome, almost as large in diameter as the boiler itself, was placed just hack of the smokebox. The connection of this dome with the barrel was a serious source of weakness, and the Camels were subject to rather frequent explosions.
Five additional locomotives of this type, but of somewhat larger dimensions, were placed on the Lackawanna in 1856. When operated at slow speed they were fairly successful, but they soon failed at speeds exceeding ten miles an hour. All were scrapped in 1859, as they were considered unsafe to operate.
The next Lackawanna engine demanding our attention was the Lehigh, built by the New Jersey Locomotive Works of Paterson, and completed in February. 1855. This engine was originally designed by Zerah Colburn. who was one of the most noted mechanical engineers of the period. It was of the 0‑6‑0 type, with an overhanging firebox of 7' 6" in width. Colburn's intention was to use a firebox six feet long, but he left the New Jersey Locomotive Works before the Lehigh was completed, and the builders reduced the length to 4' 6. The locomotive proved a poor steamer, and the firebox was subsequently lengthened to six feet, as proposed by Colburn.
Five additional locomotives of the Lehigh type were ordered from the New Jersey Locomotive Works in 1856, and all of them were partially rebuilt with longer fireboxes about two years later.
The first really successful anthracite burners used on the Lackawanna were the Investigator and Decision, which were turned out of the shops of Danforth, Cooke and Company in April, 1857. They were of the 4‑6‑0 type for freight service, and had wide overhanging fireboxes placed back of the rear drivers.
The Philadelphia and Reading, in the meantime, was having some interesting experiences with Winans Camels. Eleven of these remarkable locomotives were in use on the road in 1852; fifteen more were purchased in 1854, at a cost of $150,000, and in the following year 17 more were bought for $165,000, making a total of 43. As originally built, the Camels had no water space in the back of the firebox; and side sheets, especially those of iron, failed frequently. Copper side sheets proved more reliable, but there was no marked improvement until Miliholland rebuilt the fireboxes with a back water space. This change also permitted him to put in water‑tube grates, which proved more durable than cast iron grates. With the latter, it was found preferable to use an inferior grade of anthracite, as the resulting accumulation of ash and cinder protected the cast iron bars from the intense heat of the fire. With high grade fuel of low ash content, the bars burned out rapidly, but this difficulty was avoided with the water‑tube grate.
It is difficult for us today to appreciate the problems which had to be solved by the men who designed these early hard‑coal burners. They realized the need for ample grate area, but had many trials and tribulations in trying to obtain it. A low center of gravity was considered essential, and hence the boiler was carried at the lowest possible elevation. A firebox with sufficient grate area for burning wood could be placed between the frames and axles, but such a location provided insufficient space for an anthracite‑burning firebox. Apparently the only alternative was to use an overhanging firebox, and this resulted in a locomotive that was liable to rock and prove unsteady on the track when run at more than moderate speed. The frames were usually stopped in front of the firebox, and hence it was difficult, to provide a satisfactory connection between the locomotive and tender. In many cases the tender drawbar was attached to the ash pan. which in turn was braced to the frames at its forward end. This was, to say the least, a most unmechanical arrangement, but it apparently served the purpose fairly well.
The problem was finally solved, on both the Lackawanna and the Reading, by raising the boiler and p1acin the firebox above the rear driving axle. Miliholland placed his grates above the frames, thus obtaining an area of 241/2 square feet in a firebox seven feet in length, He developed locomotives of the 4‑4‑0 type for passenger service, and the 4-6‑0 for freight, that had no superiors at the time of their construction. In the report of Superintendent Nicolls dated November 30, 1859 we read: 'The two new coal‑burning passenger engines Hiawatha and Minnehaha. have been completed, and in use for some months. In economy of fuel and repairs, and general efficiency, these locomotives have proved superior to any yet used, and are believed to furnish an excellent model for others which may be hereafter required for similar service". This proved to be a fact; for the Reading designs of the late fifties continued to be built, with comparatively little variation, until the advent of the Wootten boiler in 1877. Miiholland's locomotives had boilers with radial‑stay fireboxes, water‑tube grates, and two steam domes. An inspection of the drawings of the Hiawatha. shows that such features as sloping throats and back heads were not unknown at that time, and reveals a boiler which was quite as "crooked" in appearance as any built during recent years.
Under date of December 13, 1859, Millholland addressed a most interesting report, covering the subject of anthracite as locomotive fuel, to R. D. Cullen, then President of the Philadelphia and Reading Railroad Company. The report stated that there were only four wood-burning locomotives left on the railroad, and that the coal burners were far easier to manage than the wood burners, as they had to be fired only every 40 minutes. With full trains of 100 loaded cars carrying five tons per car east‑bound, and 110 empties westbound, the coal consumption for the round trip of 190 miles was nine tons.
As compared to a soft‑coal burner of the same nominal capacity, the hard‑coal burner of the sixties and seventies was somewhat heavier, with a larger percentage of total weight resting on the driving wheels. This was particularly true of the 4‑4‑0 and 4‑6‑0 types, which were built in large numbers; and was due to the long firebox of the hard‑coal burner, which extended over the back driving axle, throwing the center of gravity toward the rear. The additional weight on drivers was an advantage in the case of locomotives inclined to be "slippery". The grates of the hard‑coal burners were composed of water tubes about two inches in diameter, and in a firebox of the usual width two or three "pull‑out" bars were inserted. These rested in thimbles placed in the water legs, or sometimes, at the front of the grate, on suitable bearing castings; and they could be drawn out when dumping the fire. The usual ratio of grate area to heating surface was about 1 to 40, as compared with 1 to 60 in a soft‑coal burner.
Stacks of various kinds were used on the hard‑coal burners -- straight stacks, diamond stacks, sun‑flower stacks, and even Laird balloon stacks, were tried at various times and in accordance with the ideas of master mechanics. The straight stack finally prevailed, and became practically universal before the final discarding of the diamond stack on soft‑coal burners.
Variable exhaust nozzles were almost universally used on anthracite burning locomotives sixty or more years ago. Probably the most common type had an internal plug, which could be raised or lowered within the nozzle, thus varying the size of the annular opening through which the steam escaped. The Bolton nozzle consisted of flexible steel plates, surrounded by a cast iron ring, which could be raised or lowered, thus allowing the plates to spring apart or be drawn together, and varying the size of the opening. Ross Winans, in 1847, patented an exhaust which was used, at least to some extent, in his Camel engines. The opening in the nozzle was rectangular in cross section, and its width could be varied by changing the distance between two vertical plates. The device was operated through gearing, by a handle placed in the cab. According to Herbert T. Walker, this type of exhaust nozzle was applied to the Lackawanna Camels. The operating handle in the cab was derisively known as the "coffee mill." The device would frequently clog with cinders and become inoperative, the result being a surprising amount of railroad profanity. It was therefore customary to set it at a point which gave generally satisfactory results, and let it stay there.
The year 1866 is of special interest, because it marked the introduction of the so‑called Consolidation type of locomotive. The original "Consolidation' -- the first 2‑8‑0 type with separate tender -- was built by the Baldwin Locomotive Works to specifications prepared by Alexander Mitchell, Master Mechanic of the Lehigh and Mahanoy Railroad. At the time of its construction, the Lehigh and Mahanoy was being consolidated with the Lehigh Valley, and the locomotive was named "Consolidation" in honor of the event. The name stuck to the type. Although Matthias W. Baldwin predicted the failure of Mr. Mitchell's new engine, it proved a great success; and the Lehigh Valley took a leading part in the development of the Consolidation type for heavy coal and freight traffic. In order to obtain sufficient grate area for burning anthracite, these locomotives had fireboxes ten feet long. The big Consolidation type of the seventies had 20x24‑inch cylinders and driving wheels 50 inches in diameter, and weighed about 100,000 pounds in working order. The preference of the Lehigh Valley for these large locomotives was due to the fact that there were heavy grades on its main line, up which coal had to be hauled while moving east‑bound from the mines. The Reading, as has been mentioned, was more favorably situated in this respect, having a descending river grade east‑bound over practically its entire main line. It was handling coal traffic with Millholland Ten‑wheeled (4‑6‑0 type) engines. These were popularly known as "gun boats", and they weighed 25 to 30 per cent less than the Consolidation type locomotives.
In a report of John P. Laird, Master of Machinery of the Pennsylvania Railroad, dated December 31, 1862, it was stated that experiments were being made with a passenger locomotive designed to burn anthracite, and that the relative merits of hard and soft coal as locomotive fuel were being thoroughly tested. In the report of the following year, it was stated that the hard‑coal burner had not proved successful, and that it had been, rebuilt to use bituminous coal and was "doing very well". This was probably the Pennsylvania's first, but by no means only experience in the use of anthracite.
In June, 1871, the Pennsylvania leased the lines of the United New Jersey Canal and Railroad Company; and for many years thereafter it owned and operated a large number of hard‑coal burners. The first "standard" design of hard‑coal burner was Class C Anthracite (subsequently Class D4) which was turned out in 1873. This was a 4‑4‑0 type engine which, apart from its boiler, was practically a duplicate of Class C (or D3), a soft‑coal burner which was then the most successful all‑around passenger and fast freight engine on the railroad. As compared with Class C, the grate area of the hard‑coal burner was increased .63 percent, and the total heating surface, 7 percent. This latter increase was the result of using a larger number of tubes of reduced diameter. The total weight of the locomotive was slightly increased, while the weight on drivers was raised about ten per cent.
In 1876 John E. Wootten, then General Manager of the Philadelphia and Reading, became interested in the problem of using refuse anthracite as fuel. In a statement dated December 21, 1876, published in the Annual Report of the Company for that year, he says: "An important economy, introduced during the year, has been the utilization of coal dirt, from the waste heaps at the mines, for generating steam in stationary boilers at the shops and at stations on the line. A locomotive using this fuel is also doing efficient service. Nearly seven‑thousand tons of this waste material has thus been profitably consumed during the year".
Mr. Wootten was seriously tackling the problem of burning refuse coal in locomotives; and in January, 1877, the first locomotive with a boiler specially designed to burn this fuel was turned out of the Reading Shops. This engine, No. 408, was of the 4‑6‑0 type for freight service, with 18x24‑inch cylinders and driving wheels 54 inches in diameter. Application was made for a patent covering the new type of boiler, and this patent‑No. 192,725‑was granted July 3, 1877. It had one claim, reading as follows :
A locomotive engine in which a firebox wider than, and a grate as wide as or wider than, the distance between the driving wheels, and arranged above the same, are combined with a bridge M, extending across the said firebox, and with the auxiliary combustion chamber, all substantially as set forth.
This patent was followed by another, No. 254,581, dated March 7, 1882, which illustrated a boiler similar to that shown in connection with the first patent. The principal claim of the second patent was that the entire firebox should be above the bottom line of the waist or barrel of the boiler.
The design of the Wootten boiler showed considerable ingenuity. In order to burn refuse coal successfully it was necessary to carry a thin fire and work it with a light draft, and this necessitated a grate area far larger than could be obtained in a firebox placed between the wheels. At the same time there was a strong prejudice against raising the boiler, the fear being that such a plan would render the locomotive unstable and liable to upset when rounding curves. Mr. Wootten therefore, while extending his firebox beyond the wheels and raising it above them, used an extremely shallow throat, in combination with a combustion chamber which extended forward into the boiler barrel. There was a raised water space, surmounted by a fire‑brick wall, across the rear of the combustion chamber, and this permitted the watertube grate to be placed entirely above the bottom line of the boiler barrel. Owing to the width of the firebox, two fire‑doors were provided. The crown sheet of the firebox was horizontal, but the roof sheet sloped toward the rear at a fairly steep angle, providing very little steam space at the back. The mud ring, or water space frame, was made of flanged plates shaped like an. inverted U, and carefully fitted and riveted to the inside and outside firebox shells. The firebox was supported on the frames by means of vertical expansion links at the front and back. A short smokebox was used, with a variable exhaust nozzle and a register in the front door for the admission of air.
Two other patented devices of Mr. Wootten's were applied to engine 408. One was a grate composed of water tubes between which were placed cast iron bars having narrow air openings. The other was a feed‑water heater, consisting of a long cylindrical drum traversed by tubes through which part of the exhaust steam passed. A pump, worked from a return crank attached to the rear crank pin on the right hand side, forced water into the drum, where it absorbed heat from the exhaust steam. The condensate was drained through a pipe at the back end of the drum.
Engine 408 proved successful, and was followed by others of similar design. One of them, No. 412, was sent to Europe and exhibited at the Paris Exposition of 1878. It was subsequently tried on the Northern Railway of France and also on several Italian roads, where it burned low grade fuel with marked success.
In the first Wootten boiler locomotives constructed, including engine 412, the cab was apparently placed over the firebox. On account of restricted clearance limits on the Northern Railway of France it was necessary, before placing the locomotive in service on that line, to move the cab ahead of the firebox so that it could be lowered. This was probably the first of a long series of locomotives subsequently nicknamed "Camel‑backs" or "Mother Hubbards".
While the records indicate that Wootten boiler locomotives for passenger service were built at Reading as early as 1878, the first of such locomotives to be fully illustrated and described in the technical press was apparently engine 411, which was turned out of the Reading Shops in May, 1880. A similar engine, No. 506, followed in June. The writer has distinct recollections of both these locomotives, and he has ridden behind them on the Bethlehem Branch. They were of the 4‑4‑0 type, and were the heaviest passenger locomotives in the country at the time of their construction; and they set the pace for high‑speed motive power, not only on the Reading, but also on other railroads. Their cylinders had the unusual dimensions of 21x22 inches; the drivers had a diameter of 68 inches, and the steam pressure was 140 pounds. The boiler was of the full‑fledged Wootten type, with a grate area of 76 square feet.
Engines 411 and 506 were placed in fast passenger service on the New York line, operating between Philadelphia and Bound Brook. It was customary to change engines at the latter point, using the locomotives of the Central Railroad of New Jersey between Bound Brook and Jersey City. The Reading locomotives made two round trips, aggregating 240 miles, per day. According to the late J. Snowden Bell the fastest schedule allowed 64 minutes for the 54.9 miles between Wayne Junction and Bound Brook, including one stop and three slow‑downs. At full power 53 pounds of anthracite were consumed per minute, and 55 gallons of water were evaporated. In this severe service, each engine crew consisted of three men, one of whom served as "furnace‑door opener"; "an operation' '‑according to Mr. Wootten‑' 'which facilitates rapid firing". In regular service a speed of 72 miles an hour was maintained for a distance of eight miles; and on one occasion a special train of 15 cars was hauled from Wayne Junction to Bound Brook in 76 minutes.
The first Baldwin‑built engines to have Wootten boilers were heavy freight haulers of the Consolidation (2‑8‑0) type, constructed for the Reading in 1880. They were fitted with Mr. Wootten's patent feedwater heater, but curiously enough in this case the water was forced into the heater, not by a pump, but by an injector. In service these locomotives proved so satisfactory that they were soon followed by others of similar design. The General Manager's report dated December 31, 1881, stated that the cost of fuel per 100 ton‑miles for the Ten-wheeled engines using prepared coal was 5‑6/10 cents, while for the Consolidation using waste coal it was only 0‑6/10 cents. This represented a saving in the cost of fuel per annum, for each Consolidation type locomotive, of about $2,500.00. During the year 1883, 171 locomotives using waste anthracite, reduced the fuel cost by $378,000.00 In addition to this, the firebox sheets lasted considerably longer in the Wootten boilers than in those of the conventional type, due to the fact that it was not necessary to force the fire so hard.
The refuse anthracite, as received from the mines, usually had mixed with it from 18 to 20 per cent of slate and other impurities. When the Wootten boiler was first introduced, an attempt was made to burn this fuel without washing it; but this necessitated cleaning fires so frequently that it was found desirable to remove the impurities before placing the fuel on the tenders. In fast passenger service, to insure greater cleanliness and free steaming, it was customary to burn lump coal; but it was not necessary to "size" it specially, as was the case with the narrow fireboxes, because the Wootten boilers burned any size from stove to steamboat.
In spite of the success of Mr. Wootten's new boiler, the majority of the roads in the anthracite region resisted its introduction. This was doubtless due, at least in a measure, to the fact that it was a patented device. The Lehigh Valley, in 1880, purchased two Wootten Consolidation type locomotives from the Baldwin Locomotive Works, but adhered to the long narrow firebox for passenger locomotives. This road was building the majority of its locomotives in its own shops, and each Master Mechanic was supposed to design motive power best suited to the requirements of his particular division. Locomotives were built at South Easton, Hazleton, Weatherly, Delano, Wilkes‑Barre and Sayre; there were Kinsey engines, Campbell engines, Clark engines, Hofecker engines, Mitchell engines, anybody and everybody's engines. Apart from the fact that all burned hard coal, there was no attempt at standardization; the result, according to the late Angus Sinclair, being "the accumulation of an assortment of patterns such as no other railroad company ever possessed".
Lehigh Valley engine 382, the William L. Conyngham, built at Wilkes‑Barre in 1882, was a fine example of a passenger lump burner She was a particularly handsome 4‑4‑0 type, with 19x24‑inch cylinders, driving wheels 68-1/2 inches in diameter, and a grate 10-1/2 feet in length having an area of 36.8 square feet. This engine, in its leading features and dimensions, was representative of the general class of passenger power used on the other principal hard coal roads, such as the Central of New Jersey and the Lackawanna.
The Pennsylvania, in 1881, introduced a new series of hard‑coal burning locomotives, represented by Classes K and A anthracite, which were respectively used in fast and local passenger service on the New York Division. These locomotives were of the 4‑4‑0 type, and were designed under the supervision of the late Theodore N. Ely, who was then Superintendent of Motive Power. Class K (subsequently D6) had 18x24‑inch cylinders, and was notable for the size of its driving wheels, which were 78 inches in diameter. Class A anthracite (subsequently D7) had 17x24‑inch cylinders and 68‑inch drivers. The boilers of the two classes were closely similar, with fireboxes ten feet long placed above the frames, and a grate area of 34.7 square feet. As far as the design of the details was concerned, these locomotives represented the most advanced practice of their day. They were handsome in appearance, and there was a refinement in their outline, and an absence of gaudy paint and brass work, that contrasted strongly with much of the power in service at the time. A heavier design, with larger cylinders and boiler, designated as Class P (subsequently D11a) was built in 1883 and for several years thereafter.
In fast passenger service on the New York Division, the Class K and Class P locomotives burned hard coal during the summer time and soft coal during the winter.
It is interesting to note that in 1883 the Baldwin Locomotive Works built, for the Denver and Rio Grande Railroad, three narrow gauge 4‑4‑0 type locomotives designed to burn Colorado anthracite. These little engines, with 12x18‑inch cylinders and driving wheels 45 inches in diameter, had long narrow fireboxes, with grates composed of water tubes and pull‑out bars. They were tried in passenger service, but as hard‑coal burners they were failures, as they could not be made to steam.
The Wootten boiler, as originally designed and built, had certain features which were destined to give trouble. Due to the sloping roof sheet and the large area of crown sheet with its fiat surface, there were frequent staybolt breakages. The flanged mud ring proved a source of weakness, as did the raised water space at the back of the combustion chamber, where seams were prone to leak. The Baldwin Locomotive Works gave valuable assistance in improving the design of the boiler and eliminating its weak points. The roof sheet was made horizontal, the crown sheet was arched all the way around except at the sides, and a solid mud ring of forged iron was substituted for the plate design. The arrangement of the throat was changed so that the raised water space in, the combustion chamber could be eliminated, while retaining the water‑tube grates and fire‑brick wall.
The boiler, as thus improved, was applied to a group of 4‑4‑0 type engines built in 1889 and 1890, at which time Levi B. Paxson was Superintendent of Motive Power and Rolling Equipment of the Reading. Mr. Paxson did progressive work in developing the Wootten boiler, and also improving valve gear design by providing a freer exhaust and reducing back pressure. The 4‑4‑0 type locomotives referred to had the same size cylinders and driving wheels as the old 411 class, but the boilers were larger and the steam pressure was raised from 140 to 160 pounds. These locomotives proved a great success, demonstrating their ability, on special occasions, to maintain an average speed of 60 an hour between Camden and Atlantic City and doing very creditable work on the New York run also.
In the meantime there was being developed the so‑called modified type of Wootten boiler, which had a wide firebox without a combustion chamber. Mr. S. M. Vauclain, of the Baldwin Locomotive Works, gives chief credit to Alexander Mitchell of the Lehigh Valley, for perfecting this design. However that may be, it is interesting to note that a boiler of the modified Wootten type was applied to Baldwin engine No. 5000, an experimental single‑driver engine built in March, 1880, for high speed service on the Bound Brook line. This locomotive had the 4‑2‑2 wheel arrangement, with a wide firebox placed back of the drivers and over the trailing wheels. The firebox was radially stayed, and had a straight tube sheet and water-tube grate. The locomotive proved capable of maintaining high speed, but it made only a few trips on the Reading; and it was subsequently sold to Lovett Eames, who took it to England to exploit his patented vacuum brake.
The locomotive just mentioned had a deep firebox, with ample space between the grate and the bottom row of tubes; but when the modified Wootten design was first placed above the drivers, the throat was so shallow that trouble was experienced. The fuel choked up the bottom tubes, and cold air passing through the grate frequently caused them to leak. This difficulty was overcome by placing the tube sheet five or six inches ahead of the throat, thus causing the equivalent of a very short combustion chamber or, as it was called, a D‑head. This kept the tubes out of the fire, and gave any cold air an opportunity to heat up before it struck the tube sheet. There was nothing new about the D‑head, as it had been used for many years in narrow fireboxes. It was simply applying an old device to overcome a new difficulty.
Mr. Wootten took out several patents covering wide fireboxes with straight tube sheets. One of these described a curved brick wall placed on the grates and abutting against the tube sheet, thus keeping the fuel out of the tubes and forming a small combustion chamber. In another arrangement, the lower tubes were kept so far above the bottom of the boiler shell that the fuel could not get into them. This plan sacrificed a considerable number of tubes, with a corresponding reduction in heating surface. Mr. Wootten also took out a patent, jointly with J. Snowden Bell, under date of April 19, 1887, covering a wide firebox which was divided into two chambers by means of a longitudinal water‑leg. The chambers united, at the front of the firebox, in a common combustion chamber which was separated from the grates by walls of firebrick. If this plan of firebox was ever actually used, the writer is not aware of it.
In addition to the railroads which have been thus far mentioned, many other lines in the east were using anthracite to a greater or less extent. Among these were the Central Railroad of New Jersey, the Erie, the New York, Susquehanna and Western, the New York, Ontario and Western,, the Delaware and Hudson, the West Shore, the Long Island, the Erie and Wyoming Valley, and various smaller roads. The New York Central and Hudson River burned anthracite in suburban service out of New York City, and the switching in the Grand Central station was done with hard‑coal burners.
The West Shore had in service two classes of 4‑4‑0 type locomotives which were alike except for the fireboxes, one class burning bituminous coal and the other anthracite. Both classes had 18x24‑inch cylinders and driving wheels 68 inches in diameter, and carried a steam pressure of 14,0 pounds. Four of these locomotives, one of them a hard‑coal burner, participated in a run made on July 9, 1885, with a three‑car special train, from East Buffalo to Weehawken. The average speed while running was nearly 50 miles an hour, and the performance, at that time, was regarded as quite an achievement. The locomotives were built by the Rogers Locomotive Works, and the run is described in great detail in the 1886 edition of the Rogers catalog.
The success of the Wootten boiler, in both its original and modified forms, led to the re‑boilering of many hard‑coal burning locomotives originally having narrow fireboxes. If the drawings of these boilers could be studied, some interesting designs would be revealed. The Lehigh Valley, in a number of cases, built wide fireboxes with the Belpaire system of staying, the inside and outside firebox sheets being parallel to each other so that the stay-bolts were normal to both. This system, of construction was subsequently used by the Pennsylvania Railroad in the boilers of its first Atlantic type locomotives, which will be described shortly.
Brief reference should here be made to a number of three‑cylinder hard‑coal burners, built for the Erie and Wyoming Valley Railroad. In 1880 Mr. John B. Smith, Superintendent of the Pennsylvania Coal Company, built four small switchers of the 0‑4‑0 type, each of which had three cylinders. While records of their dimensions and service are not available, they were apparently satisfactory; for in 1892 Mr. Smith constructed, at the works of the Dunmore Iron and Steel Company, a wide firebox, three‑cylinder passenger locomotive of the 4‑4‑0 type, for the Erie and Wyoming Valley. This was followed, in 1894, by three freight locomotives of the Mogul (2‑6‑0) type, built by the Baldwin Locomotive Works. In this design there were three 17x24‑inch cylinders set on an incline, with all the pistons connected to the second pair of driving wheels, and cranks placed 120 degrees apart. These locomotives had Wootten boilers carrying a steam pressure of 150 pounds, and developed a tractive force of 23,300 pounds. In proportion to their weight they demonstrated remarkable hauling capacity, especially on grades.
As far as the writer is aware, the only other three‑cylinder hard‑coal burners on record are those built by the Philadelphia and Reading at the Reading Shops during the years 1909‑1912. Three of these were of the Atlantic type, while the fourth was a ten‑wheeler. They all did fine work, but were subsequently rebuilt with two cylinders.
During the nineties the locomotive weight record was broken by three groups of anthracite burners, all built by the Baldwin Locomotive Works. First were the four 0‑10‑0 type tank engines, specially designed to operate through the St. Clair Tunnel near Detroit. Each locomotive was required to haul a train weighing 760 tons up the two per cent grades at the tunnel entrances. The locomotives had side tanks and a centrally located cab, the coal bunker being at the rear end. The boiler had a long narrow firebox, with a water‑tube grate having an area of 38.7 square feet. The St. Clair Tunnel was electrified in 1908.
Late in 1891 the weight record was again broken, when five Decapod (2‑10‑0) type locomotives were built for the Erie. These were intended for pushing service on the Susquehanna Hill, where the grade is 60 feet to the mile. They had Wootten boilers with combustion chambers, and rocking grates having an area of 89.5 square feet. There was a centrally‑located cab and also a commodious shelter for the fireman at the rear end. Vauclain compound cylinders were applied.
The third record‑breaker was built for the Lehigh Valley Railroad in 1898, and was intended for service on the Mountain Cut‑off near Wilkes‑Barre. Like the Erie locomotives, these Lehigh Valley engines had Vauclain compound cylinders; but the boilers were of the modified Wootten type with a D‑head firebox. The grate area was 90 square feet. On the Mountain Cut‑off each locomotive was rated to handle 1000, tons up a grade of 60 feet to the mile at a speed of 17 miles an hour.
The Brooks Locomotive Works, in 1899, built heavy anthracite burners of the Twelve‑wheeled (4‑8‑0) type for the Central Railroad of New Jersey and also for the Lackawanna. Apart from minor details these two groups were practically alike. They had single‑expansion cylinders, with piston valves, boilers of the modified Wootten type and centrally located cabs.
Excluding some switching engines, the only hard‑coal burners built by the Pennsylvania up to 1899 were passenger locomotives of the 4‑4‑0 type. The final development of this type was seen in the D16 group, which was introduced in 1895 and was built for several years thereafter. These engines had grates ten feet long, with, an area of 33.2 square feet, and were built with two sizes of driving wheels.68 and 80 inches in diameter. Since 1889 the Pennsylvania had been using Belpaire boilers on its standard passenger locomotives, and Class D16 had a boiler of that type. These locomotives were used in both hard coal and soft coals territory, and for some years worked the bulk of the fast passenger traffic east of Pittsburgh. They have now nearly all disappeared, but they were undoubtedly among the most satisfactory locomotives ever used on the road.
The first locomotives of the Atlantic (4‑4‑2) type to have Wootten boilers were built by the Baldwin Locomotive Works in April, 1896, to the order of the Philadelphia and Reading for service on the Atlantic City Railroad. The running time between Camden and Atlantic City, 551/2 miles, was being steadily reduced, and the new engines were designed to handle a train of eight cars on this run in 60 minutes, or one of six cars in 50 minutes. It was estimated that a maximum of 1400, indicated horsepower would be required to do this work. The locomotives as built, had Vauclain compound cylinders and driving wheels 841/4 inches in diameter. The steam pressure carried was 200 pounds, and the boiler had a combustion chamber, the grate area being 76 square feet and the total heating surface 1835 square feet. Under test the locomotives developed 1450 indicated horsepower at a speed of 70 miles an hour.
The success of these locomotives led the Railroad Company, in1897, to put on one train which was scheduled to make the run in one hour fiat, including the time required to ferry the passengers from Philadelphia to Camden‑an operation for which the time‑table allowed eight minutes, but which invariably required more time. The train, hauled by engine 1027, ran every week‑day during the months of July ‑and August. It was composed of either five or six cars, as required, and was never once late at Atlantic City; the fastest time for the run being 46-1/2 minutes, equivalent to an average speed, start to stop, of 71.6 miles an hour. The average time consumed was 48 minutes, equivalent to a speed of 69 miles an hour. Considering both speed and punctuality, it was an astonishing record.
The Pennsylvania watched the proceedings, and in 1898 put on a sixty‑minute train which was run over, the old Camden and Atlantic Railroad. The track mileage was 58.3 as against 55-1/2 by the Reading, but the ferry at the Philadelphia end was considerably shorter, so that there was little to choose as far as running speeds were concerned. The Pennsylvania hauled their train with a 4‑4‑0 type locomotive of Class D16a which, although among the finest representatives of the type ever built, were handicapped through having to burn anthracite in a narrow firebox. Comparing the locomotives used by the two roads, it may be noted that while the Pennsylvania engine had the larger total heating surface and weight on drivers it had less than half the grate area of the Reading engine. The compound cylinders of the latter may have helped a trifle, for the high‑wheeled Vauclain compounds, when properly maintained, were fast runners; but the big grate was the feature that did the business. The Pennsylvania probably would have done better with bituminous coal, but they had to meet the Reading slogan of 'no smoke, no cinders"‑-the latter item open to doubt.
In 1899 the Pennsylvania met the situation by bringing out their first wide firebox Atlantic Type locomotives Class El. There were three of these engines -- numbers 698, 700 and 820 -- and it is safe to say that, at the time of their construction, they represented the most careful designing and the finest workmanship that could be found in this country. They met the 60‑minute schedule without difficulty and demonstrated their ability to easily maintain an average speed of 75 miles an hour from Hammonton to Drawbridge, a distance of 27.4 miles, with trains weighing 300 tons behind the tender.
In view of the many interesting details of Class El, including the cylinders, the valve gear and machinery, the frames and running gear, and the boiler, a complete description of this class would require a lengthy article. Our interest centers chiefly in the boiler, which may be described as a Belpaire Wootten. The firebox had a combustion chamber with a brick wall built across the back of it, in accordance with Mr. Wootten 's design, but following Pennsylvania practice the Belpaire System of staying was employed. The crown and roof sheets were flat and horizontal, and the water spaces were of liberal width throughout. The grates were of the rocking type arranged to shake in four sections, and particular attention was given to the arrangement of the ash‑pan and smoke‑box. All these features contributed to the success of the locomotives.
The Pennsylvania's Class El may be considered as representing the high‑water mark in the development of the hard‑coal burning locomotive. It had many fine contemporaries -- such as the Black Diamond engines on the Lehigh Valley, the Baldwin and the Brooks Atlantics built for the Central Railroad of New Jersey, which were used in the New York‑Philadelphia service, and the highly efficient eight‑wheelers and ten‑wheelers of the Lackawanna -- but the rest of the story can by told in a few words. The Pennsylvania built no more hard‑coal burners; on their subsequent Atlantics they narrowed the firebox sufficiently to place the cab at the rear, and used bituminous coal as fuel.
Subsequent to the opening of the present century the railroads in the anthracite region continued, on new power, to use boilers of the Wootten and modified Wootten types, enlarging the fireboxes until grate areas reached, and in some cases even exceeded 100 square feet. Such boilers were used on locomotives of many types, notably the Pacific (4‑6‑2) for heavy passenger service, and the Consolidation (2‑8‑0) and Mikado (2‑8‑2) for freight. Watertube grates gave way‑ to those of the rocking pattern, or to a combination of widely spaced water‑tubes and rocking bars. As boiler dimensions increased it became impossible, to provide room for the enginemen in a centrally‑located cab, and the cab was moved to the rear. While these changes were taking place, the increasing cost of anthracite, and the difficulty in generating sufficient steam in very large locomotives when using that fuel alone, resulted in the general use of a mixture of buckwheat anthracite and bituminous coal. The necessity of using mechanical stoker on the largest locomotives encouraged the use of a high percentage of bituminous, as it has not been found practicable, in locomotive service, to burn straight anthracite with a stoker.
Many of the most recent locomotives now operating in the anthracite region were designed to burn straight bituminous coal; and even when mixtures are burned, Phoebe Snow is finding it necessary to keep off the railroads -- unless she rides in air‑conditioned trains. Large numbers, of former hard‑coal burning locomotives with boilers of both the full Wootten and modified, Wootten types, are now operating on straight bituminous coal. In the interest of economy it has doubtless become necessary to do this; but the resulting effect on the atmosphere in such regions as the Schuylkill and Lehigh Valleys, and other districts which might be named, is sad to see.
The Wootten boiler, although originally designed to burn refuse anthracite, pointed the way toward the development of the high‑power soft‑coal burning boiler as we have it today. To meet the demand for motive power of high capacity, the soft‑coal burning boiler gradually developed into one having the most prominent characteristics of the Wootten type ‑a wide firebox with an extremely large grate, and a combustion chamber extending forward into the boiler barrel. Therefore, although anthracite has practically passed out of the picture as a locomotive fuel, its use, in past years, was a factor of first importance in the development of the present‑day super‑power locomotive.
Rev. May 2010