use of compressed air as a otive power for locomotives has received the
attention of inventors for many years; indeed, in the early days of the
steam locomotive, "atmospheric" railways, as they were termed, bid
fair, according to the inventors and financiers, to be serious rivals
of the steam engine, for several railways were actually built and
equipped for compressed air working in Great Britain. In no instance,
however, were they practically or commercially successful, and the
atmospheric system soon disappeared. Nevertheless, in view of the
cleanliness and handiness of compressed air locomotives and their
adaptability to certain services, inventors have persevered, and
several undoubtedly satisfactory machines were introduced on the New
York elevated lines, for tunnel work, for tramway purposes, and, as
will be seen hereafter, for mining and like use.
In consequence, however, of developments in electric traction, the compressed air locomotive has hardly had a fair chance. It is probable thath had not electricity provided a remedy for the disadvantages and inconveniences of the steam locomotive in particular circumstances, the compressed air locomotive would have an established position on local railways and tramways and for miscellaneous use. For mining and factory work the pneumatic locomotive is eminently suitable, for it can be very compact and can be very conveniently arranged as regards construction; there is no furnace to be a possible source of danger and to cause the emission of fumes and smoke; and it can be used in an explosive atmosphere. It has even been claimed that the use of compressed air locomotives in mines assists in ventillation and in the supply of pure air to the workings.
In single units, compressed air cannot be an economically installed, but when there is an air-compressing plant provided for coal-cutting and other machinery, and there is a number of locomotives to be supplied from the same central station, compresed air traction can be very advantageously introduced. There are many collieries in the United States and a few in other parts of the world using compressed air locomotives, though in Germany electric traction is almost universal, and Great Britain possesses hardly any mines where locomotive traction is used at all. There is not much diversity in the design of such locomotives, and the building of them is proncipally confined to certain firms; but, as will be seen, considerable interest attaches to the designs in use.
FIG. 27. - A COMPRESSED AIR MINE LOCOMOTIVE FOR A GERMAN MINE
|The writer is not aware of any compressed air locomotives in use for any kind of work in Great Britain, or built by British firms, and on the continent there is a similar condition of affairs. There is one German mine, however, where the locomotive power is provided by compressed air, - pneumatic winding plants operated by underground compressed air engines supplied from compressors above ground are not uncommon, but they do not come within our subject. Fig. 27 is a side elevation of the form of locomotive in use in this instance. As it possesses many noteworthy and unusual characteristics, it will be worth while to describe it more in detail than is generally possible in this article, the particulars being taken from the "Jahrbuch für das Burg und Hüttenwesen in Konigreich-Sachsen," for 1894.|
|At the mine
in question, - the "Alte Hoffnung Gottes" mine, near
Freiberg, - compressed air was installed for working machinery in the
mine in 1883, some old boilers being used as reservoirs below ground,
and in 1891 a locomotive was introduced for bringing the laden tubs to
the foot of the main shaft. The longets journey made by the locomotive
is about 1000 metres; but the route is very irregular, and there are
several almost right angle turns. The locomotive is mounted on two
pivoted, four-wheeled bogie trucks, to provide for the requisite
flexibility, the bogies being spaced 2.3 metres between centres. The
main reservoir is 3.16 metres long and only 0.7 metres in diametsr, and
air is supplied to it at a pressure of 12 or 18 atmospheres, the former
pressure being used for the journey with empty tubs and the latter on
the loaded trip. For use, the air passes to a small reservoir, and
thence pasta reducing valve to a double-cylinder, vertical engine, with
cylinders 80 millimeters in diameter, of 200-millimetre stroke, and
with a usual working speed of about 100 revolutions per minute, the air
being used at a pressure of 4 or 5 atmospheres. The engine is mounted
on one of the supporting bogies, and drives directly one axle, which is
cranked, and drives the other axle of the same bogie indirectly by
means of spur gearing arranged between the cranks.
The usual air pressure for use in the mine is only about 5 atmospheres, and for supplying the locomotive a small copmpressore has been fitted, which raises the pressure on either side of the compressing piston to 12 and 18 atmospheres, respectively, the air at one pressure being conveyed by pipes to the further limit of the locomotive route, and supplied at the other pressure to the locomotive adjacent to the compressor. The Locomotive has liiting dimensions of height 1.6 metres (about 5 feet), and width about 1 metre. The gauge is 410 millimetres (about a6 inches). The usual load hauled by this little machine is four waggons, weighing about 14 cwt. loaded.
the design and building of compressed air locomotives
for mining service forms an important part of the business of the
leading locomotive firms, maore particularly the Bladwin Locomotive
Works, of Philadelphia; the American Locomotive Company, of New York,
and the H.K. Porter Company of Pittsburgh.
The following notes from the latest "Record of Recent Construction," issued by the Badlwin Works, concerning compressed air locomotives, will be intersting :-
Locomotives particularly adapted to mine haulage were first used in the United States about the year 1870. These early locomotives were operated by steam, and proved vastly more eficient and economical that the prevailing system of hauling by animal power. Their use, however, was limited to the main gangways of well-ventillated mines on account of the danger and inconveniences from fire and escaping steam and gases. In order to overcome the difficulties attending from the use of steam, compressed air was substituted. A reservoir was provided for the recption of the air, to take the place of the steam boiler, making no material chainge in the arrangement of the machinery. In this way the efficiency derived from the use of the locomotive was retained and danger avoided.
In the process of compression a large amount of heat is necessarily generated. This heat passes off and is lost as the temperature falls to that of the surrounding atmosphere. When the air is expanded in the locomotive a drop in temperature results, reaching far below that of the atmosphere; this has a marked effect on the final volume of the air used in the cylinders. An increase in economy and efficiency will, therefore, be obtained by restoring to the air some of its lost heat. An efficient system of reheating would be hihjly desirable were it not for the complication involved, and the fact that for mine service the process of reheating brings with it the very danger which the use of compressed air is intended to avoid. It should be borne in mind, however, that the temperature of expanding air falls far below that of the surrounding atmosphere, which, under these conditions, acts as a reheating medium by contact with the outer surfaces of the tanks or cylinders. Any increase, therefore, in the amount of surface of tanks or cylinders exposed to the atmosphere is a direct gain. In view of this fact, the outer surfaces of the cylinders are ribbed, causing them to present a greater area for absorption.
Within certain limits compressed air is preferable to steam or electricity for mine haulage. Compressed air locomotives, as compared to those using steam, differ but slightly, so far as machinery is concerned. The steam generating apparatus is entirely eliminated, simplifying the construction and doing away with the part of the locomotive which requires the greater amount of skill to operate. As long as the air supply is maintained, they are capable of handling the same load in proportion to their tractive power as locomotives operated by steam, and have the advantage of being entirely free from fire, gas or vapour.
With electricity, especially for large units, the trolley system is the only one ordinarily available, and the locomotive is confined in its range to that of the supply conductor, whereas with compressed air the locomotive is at liberty to run in any direction on any avaiable track to the limit of its charge. The cost of installation for compressed air compares favourably with that for electricity.
It is possible to charge the locomotive direct from the compressor; but this system, although economical in some respects, would necessitate an increase in size of both the compressor and the locomotive. It is preferable, therefore, toprovide stationary reservoirs at convenient point in the mine, from which a supply of air can be readily drawn to recharge the locomotive tanks. This enables the compressor to be run continuously and restore the depleted reservoirs to their normal pressure while the locomotive is doing its work. Where the system requires a considerable length of piping, the pipe line itself will supply sufficient capacity without extra stationary reservoirs.
The charging stations shold be located at convenient points, preferably at the ends of the run, or where the locomotive is, for other reasons, required to stop. This will economise the air by avoiding the neccesity of running the engine any considerable distance simply for the purpose of recharging. The connection and stop valves for the charging stations are arranged with a view to ready adjustment and speedy supply, in prder that the locomotives may not be detained longer than is absolutely necessary while receiving their charge. After the oprration becomes familiarm the time required for making connections and recharging is ordinarily less than one minute.
A compressed air locomotive consists essentially of a storage tank mounted upon driving wheels, with two engines to convert the pressure in the tank into direct motion at the wheels. The general details of construction and the materials respectively employed are similar throughout to those of locomotives operated by steam. One or more storage tank may be emplyed, as may be found suitable to meet prescribed conditions. Compound cylinders are sometimes applied to compressed air locomotives. With this system the cycle of expansion occupies a longer period of time for the same speed, and consequently a greater oppertunity for heat absorption from the outside air is obtained.
|One of the
first compressed air locomotives to be put into successful
operation was built by the Baldwin Locomotive Works for the Plymouth
Cordage Company, of North Plymouth, Mass. The locomotive, one of small
size, having a single tank and cylinders 5 by 10 inches, was ordered in
1876 and placed in service in April, 1877. It was used for general
switching purposes and to transfer material from the storehouse to the
factory, taking the place of four one-horse teams, with three men to
The conditions of service under which the locomotive was required to operate were such as to preclude the use of steam. The fine particles of material with which the air was sometimes impregnated were highly combustible and no fire could be permitted, and the material under construction was liable to damage from the dampness occasioned by escaping steam. The compressed air locomotive, which was free from both fire and moisture, proved satidfactory to such a degree that another locomotive was ordered in 1894, and two others have since been placed in service.
be the Plymouth Cordage Company compressed air locomotive referred to
in the text?
FIG. 28. - A COMPRESSED AIR LOCOMOTIVE BUILT FOR THE ASHLAND COAL & IRON RAILWAY CO. BY THE BALWIN LOCOMOTIVE WORKS, PHILADELPHIA
illustrative of American practice, two examples of pneumatic
locomotives, built at the Baldwin Works, are shown in Figs. 28 and 29.
There is no great variety among these locomotives and so these examples
wil be sufficient for consideration in this article.
Fig. 28 shows a compressed air locomotive for the Ashland Coal & Iron Railway Company. There are three storage tanks, two of which are visible in the illustration, and a third, of smaller dimensions, is fitted between the frames. One of the large tanks is shorter than the other, to provide additional room in the cab. The air is stored at a pressure of 600 lbs. per square inch, and is used at 100 lbs. This engine requires a headway of 5 feet in height and 6 feet in width only. It will take curves of 30-foot radius.
Fig 29 illustrates a compressed air locomotive, compounded on the Vauclain system, as built for the Philadelphia & Reading Coal & Iron Company. In this engine, also, three storage tanks are provided, and the small one, from which air is taken for the cylinders is distinctly visible in the illustration above and between the larger reservoirs. Each low-pressure cylinder is above the high-pressure cylinder in one casing, and both are ribbed to facilitate the abstraction of heat from the atmosphere, as the air under pressure expands in doing its work. The air is stored at a pressure of 600 lbs. per square inch, and is reduced to a working pressure of 200 lbs. The engine is of very reasonable dimensions, and is guarunteed to haul thirty-two trucks weighing one ton each on a grade of 1 in 60, - very good work for such a machine.
FIG. 29.- A COMPOUND COMPRESSED AIR MINE LOCOMOTIVE BUILT FOR THE PHILADELPHIA & READING COAL & IRON CO. BY THE BALDWIN LOCOMOTIVE WORKS. NOTE THE SMALL AIR TANK ON TOP OF THE LARGE ONES
FIG. 30. - ANOTHER BALDWIN ENGINE. ONE OF THE AIR TANKS IS SHORTER THAN THE OTHER TO PROVIDE MORE ROOM IN THE CAB
used in the warm atmosphere of a mine and when properly designed, the
chief drawback attending the use of air under pressure, namely, the
liability to freezing as the air expands in use, is overcome, and
these and dozens of similar locomotives are to-day doing good work in
America and elsewhere. In practice it is found that the locomotyives
can work for considerable distances, and can stay away from the
charging stations for comparitively long periods; they are, moreover,
weight for weight, quite as powerful, if not more so, than
corresponding steam locomotives.
Taubeneck has provided me with the following information on this
40" gauge H. C. Frick Coke Co. locomotive number 41 was Baldwin works number 17857 06-00. An vauclane compound compressed air loco 0-4-0 with 3.75 & 6X10 cylinders to 24" drivers.
FIG. 31. - ONE OF THE H.K. PORTER COMPANY'S COMPRESSED AIR LOCOMOTIVES IN SURFACE USE FOR CONSTRUCTION WORK
a US Navy locomotive, see detail from cab side:
The first flat car is also marked "U.S. NAVY" and bears the number "5".
FIG. 32. - A HEAVY COMPRESSED AIR SHIFTING LOCOMOTIVE MADE BY THE H.K. PORTER COMPANY, PITTSBURGH, PA.
32 and 33 show a couple of double and triple-tank designs of the H.K.
Porter Company, of Pittsburgh, one of the leading American makers of
this class of locomotive.
may, or may not, be the same locomotive featured in figure 31 above.
There are some differences in the cab side detail and the couplings,
but again the marking "U.S. NAVY" in clear on the cab side, but the
upper line of text is still unclear.
The locomotive is marked as "1" on the front roundel.
FIG. 33. - A HEAVY THREE-TANK COMPRESSED AIR LOCOMOTIVE FOR UNDERGROUND WORK IN THE MINES OF THE HOMESTAKE MINING CO. MADE BY THE H.K. PORTER COMPANY
The application of the principles of the motor road vehicle for the purpose of rail traction is an almost inevitable result of the ever-increasing introduction of the motor car, and the last year or two has shown that makers have realised the great possibilities of motor-cars type vehivles for use on railways, and especially for shunting work, where the locomotive may lie idle for hours and yet be required ata moment's notuce. Even for high-speed work light motor vehicles have been suggested, and numerous tramway and railway vehicle driven by gas and petrol engines have been advantageously introduced, notwithstanding the inconveniences and disadvantages, - as the steam locomotive engineer would term them, - attending the use of heavy gearing and multi-speed gears. But as shunting machines these vehicles are more convenient than steam locomotives, as they are always available for use and there is no furnace and boiler to require attention. They can also be used as single machines, whereas compressed air and electricity require central stations to supply the motive power.
For mining work, - gold mines, quarries, and surface work about collieries, etc., - they have recently been introduced in several cases, and the prospects of their extensive adoption for such work, and for industrial applications generally, are exceedingly promising. The writer has investigated this subject thoroughly, and must thank various friends conversant with the work of motor-car builders for information, and the builders themselves for supplying photographs and particulars for the machines now to be described.
34 illustrates a small locomotive, of which several have been supplied
by the builders and designers, the Wolseley Tool & Motor Car
Company, Ltd., of Birmingham, England, for service in South African
gold mines. It has a wheel-base of 4 feet 6 inches, and is designed for
18-inch standard light railway track. Its maximum height is 3 feet 6
inches, its greatest width 3 feet 4 inches, and its length over buffer
beams 11 feet. The locomotive runs on four 18-inch wheels, all of which
are drivers. The motor is of the two-cylinder, horizontal tyoe. The
engine develops about 20 horse-power. Three changes of speed in the
gear box give four, eight or fifteen miles per hour. Powerful hand
brakes are provided, and a water-cooled band brake is fitted to the
high-speed countershaft. All opereating gear, lubricators, ignition
gear, brakes, etc., are well within the driver's reach, and he is
accomodated with a comfortable seat looking across the engine.
Petroleum and water tanks, of an approximate capacity of 30 gallons
petroleum and 40 gallons water, are provided, thus enabling the
locomotive to run continuously for well over ten hours. The whole of
the mechanism is neatly encased by a detachable sheet metal cover
having conveniently situated doors for the ready inspection of all
FIG. 35. - A PETROL SHUNTING LOCOMOTIVE MADE BY THE MAUDSLAY MOTOR CO., LTD., COVENTRY, ENGLAND
Fig. 35 is shown a large shunting machine recently supplied by the
Maudslay Motor Company, of Coventry, England, to the City of London
Corporation for service in the Deptford Cattle Market. There are four
coupled wheels driven by a Maudslay three-cylinder motor with cylinders
9 inches in diameter and of 9-inch stroke. The locomotive is capable of
hauling a load of 60 tons on the level, but is only adapted for slow
speed in shunting work, though two speeds are provided, as it has to
travel sometimes through the public streets. In addition to powerful
hand brakes, a vacuumn brake is fitted. Fig. 36 shows this locomotive
FIG. 36. - A MAUDSLAY PETROL LOCOMOTIVE AT WORK
FIG. 37. - A BLAKE LOCOMOTIVE IN SERVICE
contradistinction to this large and powerful machine, it will be
interesting to consider a very small motor built recently by Mr. F.C.
Blake, of Kew, England, for use at the precipitation works of the
Richmond Main Sewerage Board, at Mortlake, which is illustrated in Fig.
38, and is shown at work in Fig. 37. The locomotive is fitted with a
Blake two-cylinder, 6 H.P. petrol motor, and all four wheels drive. The
gauge of the rails is 2 feet, 9 inches. There are two speeds, forward
and backward, the locomotive being geared to run from three to seven
miles per hour, hauling a load of 4½ tons up a gradient of 1 in
25, and 8 to 10 tons on the level. The weight of the engine is about 16
cwt. It is used on a short line from the precipitation works to the new
private dock on the Thames side, and loads and unloads barges with
sludge, coal, chemicals, etc. The average week's haulage is 250 tons,
and the cost of petrol and lubricating oil amounts to about eight
shillings per week.
The line is only a short one, but there is a good deal of shunting and the gradients are bad. A lot of time is taken up waiting for aload, and this is where the petrol locomotive scores heavily over the steam locomoyive. A common labourer or navvy drives it, as well as attending to the loading and unloading of the sludge.
The engine easily displaced two horses that were previously used at this work, and had been in use since November, 1902, with great success. The wheels are mounted in gun-metal-lined axle boxes, mounted in horn plates, with spiral springs between boxes and the frame, the latter being of channel steel. The engine is put in and out of gear by a cone friction clutch, and gears are changed with finger or dog clutches, one or the other gear being always in mesh. The drive from the gear shaft is by a heavy roller chain, and both axles are coupled together by another chain and chain wheels. The greater part of the weight of the motor is placed over the leading axle. The driver is provided with a seat at the back, within convenient reach of the various controlling levers.
FIG. 38. - A PETROL LOCOMOTIVE MADE BY F.C. BLAKE, OF KEW, ENGLAND, FOR THE RICHMOND MAIN SEWERAGE BOARD
FIG. 39. - A PETROL LOCOMOTIVE BUILT BY M.M. PANHARD & LEVASSOR, PARIS
well-known French firm of Panhard & Levassor has also done a little
work in this direction, and two of their productions are shown in Figs.
39 and 40, the one being intended for postal service and the other for
light railway work. These machines are not strictly industrial machines
in the sense contemplated by this article, but they are applicable to
such work. Fig. 41 illustrates another form of petrol locomotive built
by this firm, the covers being removed to show the mechanism. This
block is reproduced from Le Chauffeur.
The motor and gearing are of the same patterns a are applied to motor
road vehicles built by this firm.
FIG. 40. - A PANHARD & LEVASSOR PETROL LOCOMOTIVE FOR LIGHT RAILWAY SERVICE
FIG. 41. - A PANHARD & LEVASSOR LOCOMOTIVE PARTIALLY DISMANTLED, SHOWING THE WORKING MECHANISM
FIG. 42. - A PETROL LOCOMOTIVE BUILT BY MESSRS. KERR, STUART & CO., LTD., LONDON
locomotives described above have been produced by automobile buildres;
but the locomotive now to be considered has been built by a firm
previously concerned, almost exclusively, with steam locomotives. Fig.
42 illustrates a very convenient internal combustion locomotive, or, as
the builders syle it, a kerosene locomotive, lately buil by Messrs.
Kerr, Stuart & Co., Ltd., of London, England. These engines are
designed mainly for use on very light railways and for other work for
which ordinary steam locomotive is almost impracticable. THey may be
used on a gauge as narrow as 16 inches and on rails as light as 10 lbs.
per yard, and can be worked equally well with either ordinary kerosene
(petroleum used for illuminating purposes), pterol or alcohol. The
consupmtion of kerosene is about 0.75 lbs. per brake horsepower per
hour, and petrol or alcohol in equal proportions. The main features of
the locomotive, apart from details of the motor and gearing, with which
we cannot at present deal, are shown by the illustration, and further
description is hardly neccessary. The mechanism can be enclosed in a
suitable casing, and Fig. 43 illustrates a suitable closed construction
adapted for use in curcunstances where protection is neccessary.
FIG. 43. - A PETROL LOCOMOTIVE, - OPEN TYPE, - BUILT BY MESSRS. KERR, STUART & CO., LTD.
|A few other
petrol-driven motors have been built for running pleasure lines and for
similar purposes, and such designs only require development to produce
industrial machines suitable for mine and factory use. Inspection
velocipedes and platelayer's lorries as used on railways are also used
in many parts of the world, and the writer has particulars of several
of these, as built by the Simms Manufacturing Company, LTD., of
Kilburn, England, and other firms, though they hardly come within the
field of the subject here.