The following chapter is reprinted from "The Young Engineers' Guide", published in 1907 by the Frederick J. Drake & Company of Chicago, Ill. We thought our readers would enjoy the authors' comparisons of some of the various engines available at that point in time.
J. I. Case Steam Traction Engine These engines are among the simplest and at the same time most substantial and durable traction engines on the market. They are built of the best materials throughout, and are one of the easiest engines for a novice to run.
They are of the side crank types, with spring mounting. The engine is supported by a bracket bolted to the side of the boiler, and a pillow block bearing at the firebox end bolted to the side plate of the boiler.
The valve is the improved Woolf, a single simple valve being used, worked by a single eccentric. The eccentric strap has an extended arm pivoted in a wooden block sliding in a guide. The direction of this guide can be so changed by the reverse lever as to vary the cut-off and easily reverse the engine when desired.
The engine is built either with a simple cylinder or with a tandem compound cylinder.
In the operation of the differential gear, the power is first transmitted to spur gear, containing cushion springs, from thence by the springs to a center ring and four bevel pinions which bear equally upon both bevel gears. The whole differential consequently will move together as but one wheel when engine is moving straight forward or backward; but when turning a corner the four pinions revolve in the bevel gears just in proportion to the sharpness of the curve.
There is a friction clutch working on the inside of the flywheel by means of two friction shoes that can be adjusted as they wear.
There is a feed water heater with three tubes in a watertight cylinder into which the exhaust steam is admitted. The three tubes have smaller pipes inside so that the feed water in passing through forms a thin cylindrical ring.
The traction wheels are driven from the rims. The front wheels have a square band on the center of the rim, to prevent slipping sidewise. The smokestack is cast iron in one piece.
The firebox will burn wood, coal or straw, a fire brick arch being used for straw, making this fuel give a uniform heat.
The boiler is of the simple locomotive type, with water leg around the firebox and numerous fire flues connecting the firebox with the smokestack in front. There is safety plug in crown sheet and the usual fittings. The water tank is under the platform. The steering wheel and band wheel are on right side of engine. An independent Marsh pump and injector are used. The Marsh pump is arranged to heat the feed water when exhaust heater cannot be used. The governor is the Waters, the safety valve the Kunkle.
The Frick Company Steam Traction Engine The most noticeable feature of this engine is that it has a frame mounted on the traction wheels entirely independent of the boiler, thus relieving the boiler of all strain. This is an undeniable advantage, since usually the strain on the boiler is great enough without forcing the boiler to carry the engine and gears.
The gearing to the traction wheels is simple and direct, and a patent elastic spring or cushion connection is used which avoids sudden strain and possible breakage of gears. Steel traction wheels and riveted spokes. Differential gear in main axle, with locking device when both traction wheels are required to pull out of a hole. The reverse gear is single eccentric, the eccentric turning on the shaft. It is well adapted to using steam expansively. The crown sheet is so arranged as not to be left bare of water in going up or down hills. Working parts are covered dust proof. Engine has self-oiling features and sight feed lubricator. Friction clutch in flywheel. Safety brake on main axle. Engineer's platform mounted on springs and every part of engine requiring attention can be reached conveniently from platform.
Crank is center type. Cross-head pump is used. Usual fittings.
These engines are built with boiler of locomotive type for burning wood and coal, and of return flue type for burning straw. They are also built of three general types. 'Corliss-pattern' frame, 'Standard' and 'Compound.'
The engine is side crank, mounted on brackets attached to the sides of the boiler. The bedplate, cylinder and guides are bored at one operation and cannot get out of alignment. Cylinder has wide ports and free exhaust, and piston has self-setting rings. The genuine link reverse gear is used, as on locomotives, and it undoubtedly has many advantages over any other, including an easily adjustable variable cut-off by correct setting of reverse lever.
The differential gear is heavy and effective. A patent steering attachment, with spiral roll, holds chains taut and gives positive motion. Friction clutch is mounted on engine shaft and connects with the hub of the pinion on this shaft. Rigid pinion is also provided. Cross-head pump and injector are used, and Pickering governor with improved spring speeder, permitting quick and easy change of speed; also Sawyer's lever for testing safety. Steam passes direct from dome to cylinder, without loss from cooling or condensing. The steel water tank can be filled by a jet pump operated by steam.
D. June And Company Steam Traction Engine This is one of the very few traction engines built with upright boiler, but it has been widely used with great success as a general road locomotive.
The engine is mounted on the water tank. The weight of the boiler comes on the hind wheels, and makes this type of engine superior for pulling. It is claimed that it has no equal on the market as a puller. The upright type of boiler has the advantage that the crown sheet is never exposed and it is claimed flues will last longer than in horizontal type. It works equally well whether it stands level or not, an advantage that no other type has.
This type gets up steam more quickly than any other it is said, from cold water, in twenty minutes. The steam is superheated in a way to economize fuel and water. By being mounted on the tank, the engine does not get hot as it would if mounted on the boiler, and the corresponding straining of parts is avoided. A patent water spark arrester is used which is an absolute protection.
The engine is geared to the traction by a chain, which can easily be repaired as the links wear. The friction clutch works inside flywheel. Engine has a new reversible eccentric, and differential gear, with usual fittings.
Nichols & Shepard Steam Traction Engine The builders of this engine lay special stress upon the care with which the boiler and similar parts are constructed. The important seams are double riveted, and the flue sheet is half inch steel, drilled instead of punched for the flues, and fitted with seamless steel flues, all of the best steel.
The boiler is the direct flue locomotive type. The crown sheet slopes backward to allow it to be covered with water in descending hills. Boiler has round-bottom firebox. Axle passes around below the boiler, and springs are provided.
The engine is mounted on a long heater, which is attached to the side of the boiler. The locomotive link reverse is used, with a plain slide valve.
Cross-head pump and injector are used and improved pop safety valve. Cylinder is jacketed, and cross-head guides are rigid with cylinder, so that perfect alignment is always secured.
Engines are built to burn coal or wood. A straw burner is provided with firebrick arch. Compound engines are also built.
The Huber Steam Traction Engine The Huber boiler is of the return flue type, and the gates are in the large central tube. This does away with the low-hanging firebox, and enables the engine to cross streams and straddle stumps as the low fire box type cannot do. The cylindrical shape of the boiler also adds considerably to its strength. The water tank is carried in front, and swings around so as to open the smoke box, so that repairs may be made on the fire tubes at this end easily in the open air.
With water front return flue boilers the workman has to crawl through entire length of central flue. As there is no firebox, the boiler is mounted above the axle, not by bolting a plate to the side of the firebox. The boiler is made fast to the axle, which is mounted on wheels with spring cushion gear, the springs being placed in the wheel itself, between the two bearings of the wheel or the hub on trunnions, which form the spindle for the hub. The wheel revolves on the trunnion instead of on the axle, and there is no wear on the axle. The traction gear has a spring connection so that in starting a load there is little danger of breakage. The compensating gear is all spur. The intermediate gear has a ten-inch bearing, with an eccentric in the center for adjusting the gear above and below. There is a spring draw bar and elastic steering device. An improved friction clutch works on inside of flywheel. Engine has a special governor adapted to varying work over rough roads, etc.
A single eccentric reverse gear is used, with arm and wood slide block (Woolf); and there is a variable exhaust, by which is a strong draft may be quickly created by shutting off one of two exhaust nozzles. When both exhausts are open, back pressure is almost entirely relieved.
The steam is carried in a pipe down through the middle of the central flue, so that superheating is secured, which it is claimed makes a saving of over eight percent in fuel and water. The stack is double walled with air space between the walls.
A special straw-burning engine is constructed with a firebox extension in front, and straw passes over the end of a grate in such a way as to get perfect combustion. This make of engine is peculiarly adapted to burning straw successfully.
A. W. Stevens Steam Traction Engine This engine has locomotive pattern boiler, with sloping crown sheet, and especially high offset over firebox, doubling steam space that will give dry steam at all times. A large size steam pipe passes from dome in rear through boiler to engine in front, superheating steam and avoiding condensation from exposure. Grate is a rocking one, easily cleaned and requiring little attention, and fire door is of a pattern that remains air-tight and need seldom be opened.
The engine is mounted upon the boiler, arranged for rear gear traction attachment. Engine frame, cylinder, guides, etc., are cast in one solid piece.
It has a special patented single eccentric reverse, and Pickering horizontal governor.
There is a friction clutch, Marsh steam pump, and injector. Other fittings are complete, and engine is well made throughout.
Aultman-Taylor Steam Traction Engine The Aultman-Taylor Traction Engine is an exceptionally well made engine of the simplest type, and has been on the market over 25 years. There are two general types, the wood and coal burners with locomotive boilers, and return flue boiler style for burning straw. A compound engine is also made with the Wolf single valve gear.
A special feature of this engine is that the rear axle comes behind the firebox instead of between the firebox and the front wheels. This distributed the weight of the engine more evenly. The makers do not believe in springs for the rear axle, since they have a tendency to wear the gear convex or round, and really accomplish much less than they are supposed to.
Another special point is the bevel traction gear. The engine is mounted on the boiler well toward the front, and the flywheel is near the stack (in the locomotive type). By bevel gears and a long shaft the power is conducted to the differential gear in connection with the rear wheels. The makers claim that lost motion can be taken up in a bevel gear much better than in a spur gear. Besides, the spur gear is noisy and not nearly so durable. Much less friction is claimed for this type of gear.
The governor is the Pickering; cross-head pump is used, with U.S. injector, heater, and other fittings complete. A band friction clutch is used, said to be very durable. Diamond special spark arrester is used except in straw burners. The platform and front bolster are provided with springs. The makers especially recommend their compound engine, claiming a gain of about 25 percent. The use of automatic band cutters and feeders, automatic weighers and baggers, and pneumatic stackers with threshing machine outfits make additional demands on an engine that is best met by the compound type. With large outfits, making large demands, the compound engine gives the required power without undue weight.
Avery Steam Traction Engine The Avery is an engine with a return flue boiler and full water front, and also is arranged with a firebox besides. There is no doubt that it effects the greatest economy of fuel possible, and is adaptable equally for wood, coal, or straw. The boiler is so built that a man may readily crawl through the large central flue and get at the front ends of the return tubes to repair them.
The side gear is used with a crank disc instead of arm. The reverse is the Grime, a single eccentric with device for shifting for reverse. The friction clutch has unusually long shoes, working inside the flywheel, with ample clearance when lever is off. A specialty is made of extra wide traction wheels for soft country. The traction gear is of the spur variety. There is also a double speed device offered as an extra.
The water tank is carried in front, and lubricator, steering wheel (on same side as band wheel for convenience in lining up with separator), reverse lever, friction clutch, etc., are all right at the hand of the engineer.
The traction gear is of the spur variety, adjusted to be evenly distributed to both traction wheels through the compensating gear, and to get the best possible pull in case of need.
For pulling qualities and economy of fuel, this engine is especially recommended.
Buffalo Pitts Steam Traction Engine The Buffalo Pitts Engine is built either single cylinder or double cylinder. The boiler is of the direct flue locomotive type, with full water bottom firebox. The straw burners are provided with a firebrick arch in the firebox. Boilers are fully jacketed.
The single and double cylinder engines differ only in this one particular, the double cylinder having the advantage of never being on a dead center and starting with perfect smoothness and gently, seldom throwing off belt. The frame has bored guides, in same piece with cylinder, effecting perfect alignment.
The compensating gear is of the bevel type, half shrouded and so close together that sand and grit are kept out. Three pinions are used, which it is claimed prevent rocking caused by two or four pinions.
Cross-head has shoes unusually long and wide. The engine frame is of the box pattern, and is also used as a heater, feed water for either injector or steam pump passing through it. Valve is of the plain locomotive slide type.
The friction clutch has hinged arms working into flywheel with but slight beveling on flywheel inner surface, and being susceptible of easy release. It is a specially patented device. The Woolf single eccentric reverse gear is used. Engine is fully provided with all modern fittings and appliances in addition to those mentioned. It was the only traction engine exhibited at Pan-American Exposition which won gold medal or highest award. It claims extra high grade of workmanship and durability.
The Reeves Steam Traction Engine These engines are made in two styles, simple double cylinder and cross compound. The double cylinder and cross compound style have been very successfully adapted to traction engine purposes with certain advantages that no other style of traction engine has. With two cylinders and two pistons placed side by side, with crank pins at right angles on the shaft, there can be no dead centers, at which an engine will be completely stuck. Then sudden starting is liable to throw off the main belt. With a double cylinder engine the starting is always gradual and easy, and never fails.
The same is equally true of the cross compound, which has the advantage of using the steam expansively in the low pressure cylinder. In case of need the live steam may be introduced into the low pressure cylinder, enormously increasing the pulling power of the engine for an emergency, though the capacity of the boiler does not permit long use of both cylinders in this way.
The engine is placed on top of the firebox portion of the boiler, and the weight is nicely balanced so that it comes in both sides alike.
The gearing is attached to the axle and countershaft which extend across the engine. The compensating gear is strong and well covered from dirt. The gearing is the gear type, axle turning with the drivers. There is an independent pump; also injector, and all attachments. The band wheel being on the steering wheel or right side of the engine, makes it easy to line up to a threshing machine. Engine frame is of the Corliss pattern; boiler of locomotive type, and extra strongly built.
The Rumely Steam Traction Engine The most striking peculiarity is that the engine is mounted on the boiler differently from most side crank traction engines, the cylinder being forward and the shaft at the rear. This brings the gearing nearer the traction wheels and reduces its weight and complication.
The boiler is of the round bottom firebox type, with dome in front and an ash pan in lower part of firebox, and is unusually well built and firmly riveted.
The traction wheels are usually high, and the flywheel is between one wheel and the boiler.
The engine frame is of the girder pattern, with over-hanging cylinder attached to one end.
The boiler is of the direct flue locomotive type, fitted for straw, wood, or coal. Beam axle of the engine is behind the firebox, and is a single solid steel shaft. Front axle is elliptical, and so stronger than any other type.
A double cylinder engine is now being built as well as the single cylinder. The governor regulates the double cylinder engine more closely than single cylinder types, and in the Rumely is very close to the cut-off where a special simple reverse is used with the double cylinder engine.
Engine is supplied with cross-head pump and injector, Arnold shifting eccentric reverse gear, friction clutch, and large cylindrical water tank on the side. It also has the usual engine and boiler fittings.
Port Huron Steam Traction Engine The Port Huron traction engine is of the direct flue locomotive type, built either simple or compound, and of medium weight and excellent proportions for general purpose use. The compound engine (tandem Woolf cylinders) is especially recommended and pushed as more economical than the simple cylinder engine. As live steam can be admitted to the low pressure cylinder, so turning the compound into a simple cylinder engine with two cylinders, enormous power can be obtained at a moment's notice to help out at a difficult point.
Two injectors are furnished with this engine, and the use of the injector is recommended, contrary to the general belief that a pump is more economical. The company contends that the long exhaust pipe causes more back pressure on the cylinder than would be represented by the saving of heat in the heater. However, a cross-head pump and special condensing heater will be furnished if desired.
On the simple engine a piston valve is used, the seat of the valve completely surrounding it and the ports being circular openings, the result, it is claimed, being a balanced valve.
The valve reverse gear is of the Wolf pattern, the engine frame of the girder type, Waters governor, with special patent speed changer, specially balanced crank disc, patent straw burner arrangement for straw burning engines, special patent spark extinguisher, special patent gear lock, and special patents on front axle, drive wheel and loco cab.
The usual fittings are supplied.
Minneapolis Steam Traction Engine The Minneapolis traction engine is built both simple and compound.
All sizes and styles have the return flue boiler, for wood, coal or straw. Both axles extend entirely and straight under the boiler, giving complete support without strain. The cylinder, steam chest and guides form one piece, and are mounted above a heater, secured firmly to the boiler; valve single simple D pattern. Special throttle of the butterfly pattern, large crank pin turned by special device after it is driven in, so insuring perfect adjustment; special patent exhaust nozzle made adjustable and so as always to throw steam in center of stack; friction clutch with three adjustable shoes. Boiler is supplied with a super heater pipe. Wolf valve and reverse gear. Special heavy brass boxes and stuffing-boxes. Sight feed lubricator and needle feed oilier; Gardner spring governor. Complete with usual fittings. This is a simply constructed but very well made engine.