Locomotive catechism; an up-to-date, practical and complete work on the locomotive--treating on the design, construction, repair and running of all kinds of locomotives ...

Front matter

Class ~T( TkQ2_

Book. £kl

Copyright N ,,! ^*

Preface To The First Edition

IT HAS for many centuries been the custom to give a book a preface at the last moment. For this there is probably some good reason. Sometimes it affords the author opportunity to excuse himself for his temerity, or to apologize for his shortcomings, or to repeat to the public the hopes which he and his publishers have so often exchanged, as to the book's success.

On this occasion, however, there appears to be no great amount of presumption in doing for locomotive engineers and for those who wish to become such, what I have already done for stationary engineers, actual and prospective, and what the technical press and those for whom my other Catechisms were written, have thanked me for doing. As for the hopes of success, there is not even that excuse, for the sales in advance of publication indicate that the publishers' venture will be profitable, and my own pride and author's royalties stand in no need of sympathy. There might remain the apology — but as I have done the best I could under the circumstances, and as angels could do no more (than their best, be it understood) that excuse for an excuse falls through.

Yet there must be a Preface — and a reason therefor.

Well, the reason why this is a Catechism instead of something else shall furnish the reason for the Preface.

There are some classes of information which are like unto that triumph of modern ingenuity, the six-shooter, which, when wanted, is wanted like — well, like everything, and wanted right away. The Catechetical form gives each question (hurried or leisurely) its answer, very largely independent of any other question or matter, leaving out "ifs" and "buts" and "considerings." If there are only enough such questions and answers, and if the former are properly chosen (which includes being up to date) and the latter correct, this Catechism ought to be useful and satisfactory to those who buy it. As to the number of queries — as there are nearly thirteen hundred, the ground may be said to be reasonably well covered. As to their selection — novices and expert locomotive engine-runners have chosen many of them, and examining engineers many more. Many of the rest have come to me in the line of my regular work as consulting engineer in this country and abroad. As far as able I will answer, free by mail and promptly, any question of general interest concerning the locomotive, the answer to which does not appear in the current edition.

There only remains the item of correctness in the replies. While I am a long way on the blind side of infallibility (and have the compositor and the proof reader as scapegoats anyhow, where errors are found), the reader ought to get out of the book his money's worth and his time's worth.

I hope to make and keep, through this work, as many friends as by my other Catechisms — and friends are better than money any day — and that, through my efforts, my readers may increase in knowledge and in earning power.

ROBERT GRIMSHAW.

Preface To The Twenty-seventh Edition

THIS edition has been so thoroughly revised that it may be said to be a new book from cover to cover. It has been greatly enlarged and the matter more conveniently arranged. The sixteen hundred questions and answers in the preceding edition have been increased to nearly four thousand, while over two hundred new illustrations and three folding plates have been added, making the total number of illustrations contained in the book four hundred and thirtyseven.

Most of the official questions used by prominent American railways in examining firemen and engine-runners for employment and promotion are to be found therein, with their appropriate answers.

Compound engines of the latest type receive special attention. The section on indicator diagrams should be found especially valuable as facilitating proper understanding of receiver and receiverless compounds.

The superheater, as applied in regular railway service, receives for the first time a place in a popular work on the locomotive. Among other additional subjects included is the electric headlight. That portion relating to breakdowns and other accidents, and to adjustments with a view to economy and smooth running, has received special attention ; so that there is scarcely a part of either a simple or a compound locomotive which does not find place therein.

In some cases the desirability of fully treating each heading as far as possible without time-wasting cross-references, has led to considering the same subject from different or opposite standpoints. For instance, there is under "Slide Valves""

a question and an answer on the purpose of outside lap; again, under "Cut-off and Expansion/' as to method of cut-off. These useful and intentional duplications are, however, not numerous.

Many matters referring to general steam-engine theory and practice, rather than to locomotives in particular (but including locomotive work), are treated in great detail in the author's "Steam Engine Catechism" issued by the publishers of this volume, and a careful study of which is recommended to every engineman, fireman or candidate.

The author begs to acknowledge his indebtedness to the various technical railroad journals for the use of numerous illustrations in aiding to make the Locomotive Catechism the standard book on the subject.

February, 1908. ROBERT GRIMSHAW.

LOCOMOTIVE CATECHISM.

Chapter I. General Description

Q. What are the essential features of a locomotive engine?

A. (i) Boiler, (2) engines, (3) running-gear.

Q. What name is applied to the type of boiler usually employed for locomotives?*

A. Horizontal tubular with internal fire-box.

Q. What name might be applied to the engines usually employed on locomotives?

A. Twin horizontal double-acting high-pressure non-compound, non-condensing link-motion slide-valve engines.

Q. Are all locomotive engines of the twin type?

A. Nearly all; some, however (compounds, for instance), have the cylinder on one side of different diameter from that on the other ; some have one cylinder on each side and one in the center ; some again have four cylinders.

Q. Are all locomotive engines horizontal?

A. Nearly all; but some are slightly inclined downward toward the crank-pin, and while nearly horizontal are not strictly so.

Q. What is the meaning of "double-acting" ?

A. An engine is double-acting when steam is admitted on both sides of its piston, instead of on only one, as in a Westinghouse stationary engine.

0. Are all locomotive engines double-acting?

A. Yes.

Q. W hat is the meaning of "high pressure''?

A. It is a misnomer. The term came in when non-condensing engines were first made, to represent the difference * See special section under heading " Boilers," page 40.

between an engine which worked with high-pressure steam (either with or without a condenser, but particularly without) and one which worked usually by the aid of the vacuum produced by a condenser.

Q. What is the difference between a compound and a non-compound engine?*

A. In a compound the steam exhausted from one cylinder is passed into another, there to do more work as it expands further. In a non-compound the steam after being exhausted from one cylinder does not go into any other.

Q. Is there any relation between compound and condensing engines; that is, may an engine be both?

A. Yes ; many engines, particularly marine, are both compound and condensing ; that is, the steam after being exhausted from one cylinder, in which it has done work, passes into another cylinder, there to do further work, and then goes into a condenser.

Q. What is a condensing engine?

A. One in which the steam, after having done work in a cylinder, is exhausted therefrom at a certain pressure above vacuum or above the atmosphere, and at a certain temperature, then passes into a chamber where it is cooled by contact with a jet or spray of cold water, or with sheets or tubes cooled by cold water circulating on the other side thereof.

Q. Are most locomotives non-compound?

A. Yes ; but compounds have been used in Europe for some years; and in this country, since 1890, orders for them have been increasing in proportion.

Q. Are all locomotives non-condensing?

A. Yes ; it would be impossible, at least in the present state of steam engineering, to carry on a train that would pay expenses, enough water to cool the exhaust. The time may

* See special section on " Compound Engines," page 499^

GENERAL DESCRIPTION

Fig. i. Front End View, Pennsylvania R. R. Engine, Class " O. '

come when by greater efficiency of the engine itself, calling for less steam per horse-power; by decreased friction of engine and of train, calling for less horse-power ; and by increased efficiency of condensers themselves, calling for less water per horse-power — a locomotive may be -run condensing; but that . time is not yet.

0. What is a slide-valve? *

A. A flat distributing-valve which has a to-and-fro motion upon a flat seat, usually in a direction parallel to that of the engine piston, this valve having in its working face, one or more cavities, usually serving as a passage for the exhaust.

Q. Do all locomotives employ slide-valves?

A. Nearly every one that has been built has employed a slide-valve of one sort or another. Attempts have been made to use other types, but in general have been failures, not having the simplicity, durability, and range of work of the ordinary slide.

Q. What is a link-motion engine?]

A. One in which the valve (generally a slide) is moved by being connected with a bar or link (usually slotted) which receives a vibrating motion by connection with a rod attached to strap surrounding an eccentric disk set on a driving-axle. There are usually two such disks for each cylinder, to enable reversing. The link position being varied, the amount of motion that it imparts to the valve may be altered at will.

Q. Are all locomotives of the link-motion type?

A. Most of them ; but there is a system in which the valve is moved by an attachment to levers receiving their motion from the cross-head, or from the connecting-rod between the cross-head and the crank-pin ; the amount of motion thus given being variable by slight changes in the relative and actual positions of the connecting-levers.

* See special section on " Slide Valves," page 225 f See special section on M Valve Gears," page 249.

GENERAL DESCRIPTION.

iFig. 2. Rear View, and Part Section through Cab, Pennsylvania R. R. Engine, Class " O."

Q. What name is generally applied to an engine in which a reciprocating piston drives a crank-shaft or an axle?

A. A rotatory or rotative engine, as distinguished from a rotary engine, in which the piston or follower rotates.

Q. What is the reason that locomotives have tzvo or more cylinders ?

A. Because, with a single cylinder, an engine having a crank and connecting-rod is difficult to get started in case crosshead, crank-pin, and main-shaft center get in the same straight line ; and because, in case there was but one engine, and that got crippled, it would be impossible to move the machine by its own power; whereas with two, one side may be disconnected and the other used.

Q. Are the engines of all locomotives reversible? A. Necessarily so, by the demands of the service.

Q. Which is the "back" head of a locomotive cylinder?

A. There is no such thing. There is a "crank" end, and an "out" end of both a locomotive and a stationary engine cylinder. The use of the terms "back" and "front" on either are confusing, particularly in the case of a locomotive.

Q. How may the general features for a modern locomotive be summed up?

A. As reasonable first cost ; maximum efficiency for the service, within track, weight, and clearance requirements ; the greatest proportion of adhesive weight to total ; capacity to handle the heaviest gross tonnage practicable, at the highest desired speed; greatest permissible distance between coal, water, or power stations ; economy as regards maintenance and fuel and water consumption ; substantial construction of the least number of parts ; and capacity to perform continuous service without liability of failure.

GENERAL DESCRIPTION.

CO

?ig. 3- Cross Section, Pennsylvania R. R. Engine, Class " O.

Chapter II. Classification

0. How may we classify locomotive engines?

A. As regards ( I ) ^ cylinder distribution (two, three, and four cylinders), (2) wheel arrangement (eight-wdieeler, Mogul, consolidation, etc.), (3) number of expansion stages (compound and non-compound), (4) service, etc.

Q. Considered in relation to the service for which they are intended, zvhat are the classes of locomotives ?

A. Passenger, freight, switching, elevated railway and suburban, and mining.

Q. What character of engine is required for passenger traffic?

A. Comparatively large drivers, giving high engine-speed compared with the piston-speed.

Q. What character of engine is needed for freight service? A. Comparatively small driving-wheel diameter, as to give the crank greater leverage for a given piston-stroke.

Q. What character of engines is required for work in large cities?

A. For hauling freight trains, small drivers, great tractive power, and short wheel-base ; while there is not much boilercapacity needed for the slow speeds. For passenger service, light engines that do not require great boiler-power by reason of their comparative speed. For both, those which make but little noise.

Q. What character of engine is required for suburban business?

A. Those that can start heavy trains and run them at high

CLASSIFICATION.

tR*~ o > speeds ; and usually it is well for them to be double-enders or to have valve-gear, etc., permitting them to be run equally well in either motion.

Q. What classes of engine, as regards wheel-base, are most used for passenger service?

A. In America, the eight- wheel (usually known as the American) type, having at the back two pairs of driving-axles coupled, and in front a four-wheeled swiveling truck. (This is, however, likely to be driven out by the Atlantic type, having one of the truck wheel pairs at the rear.)

Q. What is the wheel arrangement in such engines?

A. Usually with one pair of drivers back of the fire-box and the other in front; but in the Wootten engine, with wide firebox, both pairs are under the fire-box.

Q. What proportions of American engines are used in passenger service?

A. From ten to twenty-five per cent.

Q. For a 70-ton freight train on a good road, with plenty of grades, but none over 50 feet in the mile or say 1 in 100, what engine might be selected?

A. Say an 18-inch x 26-inch with 62-inch wheel centers, and weighing about 65 net tons; pressure about 180; traction at slow speed about ten tons.

Q. What is the reason for having the fire-box over both pairs of drivers?

A. To get a very wide and long grate.

Q. What arrangement of engine is desirable for local passenger service only?

A. One type is double-ended ; has four wheels coupled, and a pony truck at each end, with saddle tank. Another type is also double-ended, but instead of a saddle tank has a back tank ; there being a four-wheeled truck under the tank, and a pony truck in front.

CLASSIFICATION.

Q. What class of engine is suitable for express passenger service?

A. First of all, the American or eight-wheeled type, having

Fig. 5. Express Passenger Engine, American Type

Fig. 6. Express Passenger Engine, with Pony Truck.

two pairs of drivers coupled, and a four-wheeled truck in front, as in Fig. 5 ; then a modification of this has also four wheels coupled, but instead of a four-wheeled truck in front there is a pony truck there and another in the rear, as shown in Fig. 6 (Atlantic type).

Q. In deciding upon the best type of locomotive for a given service, zt'hat points must be taken into consideration ?

A. Train weight, speed, grades, curvature, frequency of stops, smooth operation, and low cost of repairs.

Q. What is desirable in relation to smooth operation and low repair cost?

A. The fewest possible driving wheels that will give good starting power.

0. Of zvhat is the Atlantic or 4-4-2 type the outcome?

A. Of the demand for a locomotive combining large heating surface and grate area with large driving wheels, to meet conditions which could not be met by the so-called "American'* or 4-4-0 type.

0. For what class of fuel is the Atlantic type specially suited?

A. For bituminous coal.

Q. In what other particular is the Atlantic type favorable?

A. Good water circulation.

Q. For zvhat class of trains is the Atlantic the ideal type?

A. For those of moderate weight, especially with relatively long runs with infrequent stops.

Q. What is the proportion of weight on drivers of the Atlantic type to the total zveight?

A. About 55 per cent.

Q. In what special particular does this type shozv a high ratio?

A. Pounds of total weight per square foot of heating surface ; the weight here being minimum.

Q. What is a further development of the Atlantic or 2-4-2 type?

A. The Pacific or 2-6-2.

Q. For what class of service is this type best adapted?

A. To meet the exactions of the heaviest passenger service — as for instance trains of 500 to 600 tons weight, where the cars are to be heated and lighted from the locomotive.

Q. How large do the grate areas run?

A. From 40 to 50 square feet.

Q. What is the average proportion of total weight on drivers in this class?

A. 60 per cent.

Q. What kinds of trailing trucks have the Pacific type?

CLASSIFICATION.

A. Two, with inside and with outside bearings.

0. Of these two, which is the more simple and the lighter. 7

A. The inside bearing style.

0. What is the special advantage of the outside bearing type?

A. A wide supporting base at the rear of the locomotive, giving good riding qualities. Further, the brake hangers for the trailing wheels may be attached to the truck frame, so that they move with the wheels on curves. Outside bearings also have the advantage that they are readily accessible for lubrication, examination and renewal of packing, and for such repairs as the renewal of springs and journal bearings.

0. For metropolitan and suburban traffic zvhat is the most frequently used type of engine?

A. The regular American eight- wheel ; but there are a good many that have only a two- wheel ("pony") or Bissell truck in front of the cylinders, to put more weight on the drivers.

Q. Where are the zvater and fuel often carried on engines for city and suburban traffic?

A. On an extension of the frames, back of the fire-box, and. borne by a pony truck. (See Fig. 7.)

Fig. 7. Switching and Local Passenger Service, with Back Tank. Modified Forney Type.

Q. What name is given to this latter type? A. Forney, from its inventor.

Q. What is the principal type of engine used for freight?- A. In this country, the eight-wheel type is doing most of the work in this line too, but where specially intended for this traffic they usually have smaller drivers than for passenger work.

Q. For heavier freight service, where greater tractive power is desired than can be had with only two driver pairs, what arrangement is made?

A. More drivers are added, as in (i) the Mogul (Fig. 8), in which there are three pairs of drivers and a pony or two-wheel truck; (2) the consolidation, in which there are four pairs of drivers and a two- wheel truck (Fig. 9) ; (3) the ten-wheeler, in which there are three pairs of drivers and a four-wheel truck (Fig. 10) ; (4) the twelve- wheeler, in which there are four pairs of drivers and a four-wheel truck; and (5) the decapod, in which there are five pairs of drivers and a two- wheel truck. (Fig. 11.)

Q. For what class of service is the Mogul or 2-6-0 type adapted?

A. For freight service on comparatively level roads ; or on heavy rails, where a large load per axle is permissible, and even for comparatively fast freight service.

Q. What proportion of the total weight of the Mogul is on the drivers?

A. Averaging 80 to 85 per cent.

Q. What about its boiler capacity?

A. There may be provided sufficient for moderate speeds ; and wide grates may be used because of the usually chosen small drivers.

Q. How is depth of throat sheet secured?

A. By sloping the fire-box down at the front end between the second and the third pair of drivers.

Q. What class of engine is best adapted for fast freight?

A. The ten-wheeler is coming into great favor for this purpose; having six wheels coupled and a four-wheeled truck, as shown in Fig. 10, page 27.

CLASSIFICATION.

Q. For what other class of traffic is the "ten-wheel" or 4-6-0 type adapted ?

A. For heavy and fast passenger service ; requiring a tract-

Fig. 8. Mogul Freight Engine with Tender

ive power that six wheels alone can give without overloading the fish plates and does not require too much steam. Having great hauling capacity in proportion to the total weight,

Fig. 9. Consolidation Engine for Heavy Freight.

it is a good type for passenger service, not calling for sustained high speed. It is also good for freight trains of moderate weight and high speed, having more speed than the 2-8-0 or Consolidation type.

Q. With what sized drivers is it best adapted as an "all-around" engine for passenger and fast freight service?

A. About 63 to 69 inches.

0. What is the limitation of this type in passenger service?

A. The driver diameter, as where the drivers are over 73 inches the fire-box may not be extended laterally over the rear drivers.

Q. How may the throat sheet be given sufficient depth with this type, where the drivers are, say, 69 inches in diameter?

A. By sloping the mud ring downward toward the front end of the engine, between the second and third driver pairs.

0. For what class of fuel is it a favorite? A. Anthracite.

Q. What complaint is sometimes made of "ten-wheelers"? A. That they are easily derailed.

Q. Is this complaint justified?

A. Only this far, that the fault is as much that of the track as of the engine. Where the rigid wheel base is long, the track must have easier curves, or a wider gage on curves, or the train must go more slowly around curves than where the rigid wheel base is short. Either the track must be made to conform to the new conditions of long rigid wheel base, or the speed must be reduced on curves.

0. For heavy freight what seem to be the best adapted types of engine in America?

A. (1) The consolidation, having eight, wheels coupled and a pony truck in front as shown in Fig. 9, and (2) the decapod, having ten wheels coupled and a pony truck, as shown in Fig. 11.

Q. For what service is the consolidation or 2-8-0 type especially suited?

A. For freight service requiring high starting power, as it has a large proportion of the weight on the driving wheels, and permits, by reason of large cylinders and comparatively large drivers, starting heavy trains and working steep grades.

CLASSIFICATION.

Where desired, the fire-box may be extended laterally over the rear drivers.

0. What proportion of the total weight may be on the drivers?

A. From 85 per cent to even as high as 90 ; although this latter is rare.

0. How may the front fire-box end be given sufficient depth?

A. By sloping it downward toward the front of the engine, ending between the third and fourth driver pairs, below their tops.

Q. What is the difference, as regards the wheel-base and weight distribution, between the Mogul and the ten-wheeler?

A. In the Mogul the front drivers are nearly as far from the main or middle driver as the back drivers are ; in the ten- wheeler, Fig. 10, by reason of the back truck- wheels, which

Fig. 10. Ten-wheeler for Fast Freight

are in the rear of the cylinders, the front drivers are quite clo^e to the middle pair, and thus get proportionately less weight.

Q. What is the advantage of increasing the number of drivers?

A. It enables adding to the engine weight, which gives traction, without putting so much load on any one pair of drivers as to wear the rail unnecessarily or to be injurious to rail- joints.

LOCOMOTIVE CATECHISM.

Q. Is the Mogul engine ever used for passenger service? A. Yes, but it is usually restricted to freight work.

Q. What is the general make-up of switching-engines? A. They usually have two or three driver pairs, short wheel-base and no truck, if for switching only, and seldom have

Fig. ii. " Decapod " for Heavy Freight.

tenders, the fuel and water being carried on the engine ; if they do, the tenders have instead of two trucks, only two wheel pairs. Such an engine with three pairs of drivers may be seen in Fig, 1 6.

Fig. 12. Engine for Switching and Local Service, with Back Tank. (Forney Type.)

Q. What class of engines is desirable for both switching and local service?

A. There are several types. One has two pairs of drivers coupled, and a back tank, with a four-wheeled truck under it ; this being the Forney type. (Fig. 12.) Another has two pairs

CLASSIFICATION.

of wheels coupled, and a pony truck in front, with a four-wheel tender, as in Fig. 15. A third is of the Forney type, that is, with a back tank supported on its own wheels borne by the engine-frame; but there is only one pair of such wheels, as

Fig. 13. Switching Engine, Saddle Tank.

shown in Fig. 7. A fourth class has four wheels coupled, and a back tank ; this being a double-ender and having a pony truck under the tank and another in front, besides two pilots. (Fig. 14.) A fifth class has four wheels coupled, a pony truck in front,- and a saddle tank, as shown in Fig. 13. A sixth type, for very heavy switching, has six wheels coupled, a saddle tank, and no truck.

Fig. 14. Switching and Local Passenger Engine.

Q. What class of engine is suitable for heavy switching and local freight?

A. The double-ended saddle-tank engine having six w T heels coupled and a pony truck in the rear, as last mentioned, as used for light switching, etc. ; or a double-ended engine with back tank borne on a four-wheel truck, and having six wheels

LOCOMOTIVE CATECHISM.

coupled. A third class is a double-ender, with both a saddle tank and a back tender, the latter being borne by a four-wheel truck, there being six wheels coupled. (See Fig. 16.)

Q. Why are all the wheels of switching-engines drivers?

Fig. 15. Switching Engine, with Four-wheeled Tender.

A. In order to utilize for tractive purposes every pound of weight of the comparatively light machine.

Q. Why are its fuel and water born s e by the switching-engine instead of carried in a tender?

A. To increase traction for a given amount of dead weight ; also because it shortens the train.

Q. What may be said of the wheel-bases of switchingen pines?

Fig. 16. Heavy Switching and Local Freight Engine, with Saddle Tank and Back Tank.

A. They are usually very short, to enable the engines to pass over curves and sharp switch-angles.

Q. What is the disadvantage of short wheel-base?

CLASSIFICATION.

A. The pitching or see-saw motion which it gives the engines.

Q. How may this be remedied/

A. By a single pair of truck-wheels at one end.

Q. What elass of engines is needed for mining purposes?

A. Very low, with excessively short stacks ; and with water-

Fig. 17. Heavy Switching Engine, Six Wheels Coupled, with Tender.

supply borne by tanks saddling the boiler or otherwise borne by the engine itself ; the fuel also being carried thereon.

Q. What is one advantage of the six-vjheel outside-conneeted type of engine, especially for mine work, or where there is much tunneling and bridging?

A. By reason of its greater length, the boiler-diameter may be reduced for a given weight of engine and size of cylinders, as compared with four-wheel-connected engines of the same power ; thus enabling reduction of hight and width, without reducing power.

Q. What is a so-called electric locomotive?

A. A self-propelled traction vehicle, running on rails and having one or more electric motors that drive its wheels and thereby propel the entire machine and enable it to haul cars.

LOCOMOTIVE CATECHISM B

Si i

I

Four Wheel Switching

Six Wheel Switching en

Eight Wheel Switching

IS

Si

Eight Wheel or American v.

Atlantic

Bicycle

SI

—en

Columbia

Fig. 18. Wheel Base Types.

CLASSIFICATION.

Mogul

Prairie

R\

Consolidation

Ten Wheel

U-U

(7)^(7)\

Twelve Wheel

Ui s:

£L

Decapod

I3L

Calumet

£L

^TO' V

St. Paul Fig. 19. Wheel Base Types.

The motors usually are supplied with electrical current either from a continuous rail laid near to, but insulated from the track rails, or from a wire suspended above the track lengthwise thereto, contact with the wire being made by a trolley or wheel on the end of a pole mounted on top of the locomotive. The electric current rail, called a third-rail, or the overhead trolley wire, as the case may be, is supplied with current by electric generators in a so-called central station and which are driven by steam or gas engines, or by water wheels. From the trolley or the third-rail shoe, electricity is conducted to a regulator or controller by which the motors may be started, stopped, or driven at any desired speed within their limits. Electric locomotives are built either with motors mounted so as to drive the axles indirectly through gear w T heels, or with the motor armature directly on the axle ; in w T hich latter case the motor is said to be gearless.