The "Last Call" page has appeared weekly on OKthePK's web site over the past couple of years. Each week a different
article told the story about various railway items of interest. While some of the articles were saved they were no longer available
online. Several of those about the Canadian Pacific Railway have been compiled here on this page. There is insufficient room to display
more than a few articles per page. As a result, "Canadian Pacific Odds and Ends - Part 2", continues this month with more
parts to follow as time progresses. Every month they will be archived to the CPR Set-off Siding web site for future online retrieval.
Beginning next month look under the articles section on the CPR Set-off Siding web site to
find these archived pages.
Richmond Compound for Canadian Pacific
New York, October, 1898.
Richmond Locomotive Works compound 2-8-0 Consolidation Canadian Pacific number 673.
One of the latest compounds turned out by the Richmond Locomotive Works is that shown by the accompanying engraving. Some of the
Weight on drivers - 126,300 pounds.
Weight on truck wheels - 16,350 pounds.
Weight, total - 142,650 pounds.
Wheel-base, total of engine - 22 feet 6 inches.
Wheel-base, driving wheels - 14 feet 6 inches.
Length over all, engine - 36 feet 10 inches.
Heating surface, firebox - 151 square feet,
Heating surface, tubes - 1,845 square feet.
Heating surface, total - 1,996 square feet.
Grate area - 32.7 square feet.
Drivers, diameter - 51 inches.
Drivers, material in centers - Cast iron.
Truck wheels, diameter - 30 inches.
Journals, driving axles, size - 8 1/2 x 10 inches.
Journals, truck axles, size - 5 x 8 inches.
Main crank pin, size - 7 x 4 3/16 inches and 6 1/4 x 6 inches.
Boiler, working steam pressure - 200 pounds per square inch.
Boiler, material in barrel - Worth Brothers steel.
Boiler, thickness of material in barrel - 5/8 inch.
Boiler, diameter of barrel - 62 inches.
Thickness of tube sheets - 1/2 inch.
Thickness of crown sheet - 5/8 inch.
Crown sheet stayed with - 1 1/4 inch stay bolts.
Dome, diameter - 28 inches.
Tank, capacity for water - 3,800 gallons.
Coal capacity - 8 tons.
Diameter of truck wheels - 33 inches.
Diameter and length of journals - 4 1/4 x 8 inches.
GP7 at Crowsnest
CP Rail GP7 number 8417 on the shop track at Crowsnest, Alberta - Aug 1975 Phil Mason.
I worked out of Cranbrook for a month or so during the summer and fall of 1975. From time to time Grant Will and myself would spend
a day railfanning in his red Jeep. Hence the photo of 8417 above.
The 8417 had been set out at the "Crow" to be power for the "Michel Switcher". By 1975, this train ran "as
required", west from the Crow, switching mostly at Michel, the telephone pole mill at Galloway, then through to Cranbrook.
Before the advent of potash traffic over the Crow, there were only a couple of trains a day over Crowsnest Pass, the UP connection
numbers 979 and 980 plus the Trail freight numbers 981 and 982. Usually, for train and engine crews, a trip to the Crow from Cranbrook
on 980 or 982 meant waiting for the westbound schedule of those trains (a short or long wait depending on what Lethbridge was
However, if you were told to set off power at the Crow on an eastbound, it meant that a Michel Switcher was planned to operate west
in the near future. There was no way of avoiding it. You could book rest and the Chief Dispatcher in Nelson would hold it for you to
run "when crew is available". The best advice was to make it into a bed & breakfast turn. Book crew rest overnight and
have the train run in daylight. Have a couple at Shorties Tavern across the yard and accept the inevitable.
"Al" was a whining "bloke" (A Montreal term for an English immigrant.) who started his railway career in Toronto
and transferred as a locomotive fireman to Cranbrook when the coal trains started up in the early 1970's. On the job, he was always
upset about something, and he had peed off many of the trainmen he had worked with. For many years, trainmen did not get paid extra for
setting off power. However, many obliged the engineer and did it for him.
On one occasion, Al was the engineer on an eastbound required to set off a GP9 for the switcher at the Crow. This of course was at
the end of his Cranbrook to Crowsnest run and he was upset about this extra task before he could go off duty. Also, the trainman working
with him indicated that he would not assist Al in disconnecting the GP9 from the power consist.
Early on in my career in the running trades, I got some good advice from a locomotive engineer about setting off older GM
locomotives. Never trust the "independent" (The locomotive air brake.) to remain applied on the locomotive being set off
without tying on a hand brake, or "cutting in" the air brake control stand in the operating cab. New GM's were not so bad.
SD40's would retain air brake pressure long enough for the engineer to complete hostling moves.
Al was not so informed about older GM's and was also not familiar with the Crowsnest shop track. On this day, he simply closed the
required valves and disconnected the hoses and pulled away. One of the Crowsnest shop tracks was connected at both ends to the yard
lead, and almost instantly, the GP9 he had set off began to roll away westward. The shop track and most of Crowsnest yard was on a
downgrade westward. Because all the air brake systems were cut out, the over speed feature and the "penalty control switch"
were not operative. As luck would have it, the tail end of his train was clear of the west switch, meaning that the runaway locomotive
would not collide with his train. It was moving way too fast for the caboose crew to climb on, so the only thing they could do was have
the Crowsnest operator warn everybody about the runaway locomotive heading west down the grade.
It made it as far as the apex of the McGillivray loop five or six miles west of the Crow. Al got major demerits and everyone else got
a reminder in the bulletin books about the proper procedures for setting off motive power. The GP9 in question flipped over on its side
at McGillivray, and was later repaired and returned to service. Eventually, a power derail was installed at the west switch of the
Details of the C.P.R. Mikado Type Locomotive
Vol. XXIII., No. 7
February 12, 1920
C.P.R. locomotive number 5302.
Progress is a force no man can stay. Richard Trevithick, the first engineer to make practical use of steam as a power for
locomotion, may have visualized in his mind's eye the future development of the steam locomotive, but the achievements of present day
engineering in this direction are doubtless far beyond the fondest dreams of the pioneers in this branch of science.
The Mikado type locomotives recently completed at the Angus shops of the Canadian Pacific Railway registers another mile post in the
progress this company has taken in keeping Canada in the forefront of mechanical evolution. The final delivery of the initial order of
10 of these locomotives has just been made and the present program calls for the construction of four new types: a Mikado type
locomotive, having a tractive effort of 56,000 pounds, two classes of Pacific type locomotives with 43,700 pounds and 42,600 pounds
tractive effort respectively, and one of the Santa Fe type with a tractive effort of 66,000 pounds.
The design of these locomotives has been carried out by the mechanical engineering staff of the C.P.R., the construction taking place
at the Angus shops, under the direct supervision of W.H. Winterrowd, chief mechanical engineer, and W.A. Newman, engineer of locomotive
construction, to whom we are indebted for the data and photos accompanying this description.
While there has been no radical change in the general design of these locomotives, they being quite similar to those constructed by
the C.P.R. in 1912, special attention has been given to detail design, and every effort has been made to produce a common-sense
locomotive, which will give reliable and efficient service and economical in operation.
Extension Wagon Bottom Boiler for Canadian Pacific Mikado Type Locomotive
A departure has been made in the design of the boiler, which is built on the extension wagon-bottom type, a feature that gives a
more pleasing appearance in the upper lines of the engine. This class of boiler, while not actually an experiment, is the first of its
kind to be adopted on the Canadian Pacific locomotives. The decision to try out this type of boiler was the result of considerable
investigation and careful study, on the part of the designing engineers of the company, regarding boiler proportions and construction,
every care being taken to insure ample steam generating capacity, combined with easy steaming qualities. Some of the reasons for the
adoption of this particular type of boiler may be briefly stated as follows: By locating the steam dome farther forward, or on the
second course, the seam construction on the course adjoining the fire box has been much simplified. The standpipe is separated from the
crown sheet by a greater distance, and therefore, is further removed from the extreme ebullitions that occur close to the fire box
section. The dry pipe is much shorter, so that the length of the steam passage, from the throttle valve to the cylinders, is
correspondingly reduced. Still another advantageous feature is the increased steam storage space thus provided, which, it is estimated,
will add materially to the superheating efficiency.
The boiler has an overall length of 38 feet 10 inches, with a diameter of 80 inches at the forward end, and 90 inches on the course
adjacent to the fire box. The capacity is based on Cole's ratio and is approximately 102.5 percent of cylinder requirements. The
2 1/4 inch tubes, of which there are 211, have a length of 18 feet 6 inches, a ratio length to diameter considered as most efficient.
Another pioneer construction feature of the boiler is the use of a 28 inch barrel combustion chamber, the first of this type installed
on C.P.R. engines. The mud ring is of special interest, inasmuch as the cast steel ends are welded to wrought iron sides, the end
portions of the steel sections being provided with drop corners to permit of through riveting for the corner fastenings of the inside
fire box sheets.
General view of the main frame forging
Experience has shown that no small amount of locomotive trouble has developed through frame breakage, and records indicate that
the majority of such breakages take place immediately behind the cylinders. In an effort to eliminate, or at least minimize, this
evident source of trouble the designing engineers have provided adequate means to reduce the twisting strains apparently resulting from
insufficient fastening at this point of the frame. The extension gives an additional depth of 15 inches directly back of the cylinders,
and this portion of the main frame is firmly bolted to a corresponding lug on the back end of the cylinder casting, giving a total
vertical bolting surface of 29 1/2 inches.
The frames are of the single front rail type, with a uniform thickness of 6 inches, which is a little heavier than is usually found
in general locomotive practice. Additional rigidity is further provided by a special wedge casting located beneath the saddle portion of
the cylinder castings and between the main frame connections. The lugs of the castings are tapered, so that a firm wedge joint is
secured by driving the lower casting into position and then bolting together with the vertical bolts to the saddle, and the side or
horizontal bolts to the frame and cylinders. These alterations in design were deemed essential, in view of the fact that the engines
will be used in sections of Canada where extremely low temperatures are frequent occurrence. The portion of the frame that carries the
trailing truck is 2 1/2 inches thick and joined to the main frame by a special offset connection.
Vaughan Trailing Truck
Elevation and cross section
of Mikado 2-8-2 locomotive and arrangement of Ragonnet reverse gear
These Mikado locomotives are equipped with the Vaughan trailing truck, a type that has given entire satisfaction on C.P.R.
engines for the 13 years they have been in continuous service. The frames for the trailing truck are located outside of the trailing
wheels and are spaced 6 feet 3 1/2 inches between centres. No radius bar is used with these trucks, the guiding motion being controlled
from inclined vertical faces on the journal boxes, which bear on corresponding inclined faces on the pedestals attached to the extension
Ash Pan Construction
One of the details of construction that has been given more than ordinary attention is the design of the ash pan. It is generally
recognized by railroad engineers that the ultimate efficiency of an engine on the road is dependent, very largely, on this apparently
minor portion of a locomotive makeup. This is particularly true in respect to those engines that may be called upon to operate in cold
climates, under which conditions it is imperative to provide ample capacity and effective facilities for the discharge of the contents.
The construction of the Vaughan truck, with its wide frame, allows of pan construction relatively free from flat horizontal surfaces,
and with quick slopes at either side of the trailer axle for clearing purposes. In fabricating the pan the joints are made with sheet
asbestos, and, wherever possible, the corner angles are placed on the exterior, so as to obtain an unobstructed surface on the inside.
The safety factor has been intentionally incorporated in the construction of the pan, so that accidental dropping of hot ash or clinker
is prevented by the automatic closing of the ash pan doors, the pivot supports of the doors being located back of the door centre of
gravity, so that the doors are self-closing immediately the operating lever is removed.
In the past it has been found that the use of dead grates has given rise to much trouble in operation, so that this type of grate has
been entirely replaced by the movable type, and the design finally adopted in these engines is of the butt finger type, 10 inches wide,
and made in four sections. The centre carrier is of very light cast steel construction, and is reinforced along the lower or tension
member by a structural tee iron. Every consideration has been given to design of side carriers to avoid excessive warping. These
carriers are in two sections, which facilitate repairs to fire box corners, as only one section of the grates need be removed.
Rods and Link Motion
General view of the rod and valve motion Mikado freight locomotive
The construction of the piston heads differs somewhat from previous practice, as exhaustive analysis, both mathematical and by
actual tests, have been made at the Angus shops to determine the specific stresses to which piston heads are subjected. The result has
been a great saving in weight, as the pistons in these engines are considerably lighter than those two inches smaller in diameter, which
have, until now, been accepted as standard on other C.P.R. locomotives. The cast iron crosshead, which is made in one piece, is a
modification of previous standard patterns. The design provides for six removable cast iron wearing pads, three top and bottom, each of
which is 7 inches long by 6 3/4 inches wide. These sections are kept in position by side plates bolted to the crosshead body.
Details of crosshead
An interesting detail in connection with the valve operating link motion is the change effected in linking up with the crosshead.
The union link is apparently fitted to the wrist pin, but actually works on a bearing formed by a step on the inside washer, which, in
turn, fits on a tapered shoulder of the crosshead body. This has the advantage of relieving the wrist pin of any thrust from the valve
mechanism through the union link.
By paying particular attention to every detail of reciprocating motion a remarkable saving has been effected in weight of moving
parts. These are all made of carbon steel, but are only 96 pounds heavier than on those used on lighter Mikado locomotives. The increase
in weight of reciprocating parts is approximately 5.87 percent, while the increased piston load is 31 percent, a creditable
Arrangement of Control
Backhead of boiler showing convenience of engine control C.P.R. Mikado locomotive
One of the problems of locomotive construction is the arrangement of the control and operating mechanism, 95 percent of which is
located within easy reach of the engineer or fireman in the cab of the engine. Effort has been made to obtain the most convenient and
efficient layout on the backhead of the boiler, so that all valves, throttle lever, lubricators, air brake control equipment, etc.,
would be properly located and at the same time allow both the engineer and firemen to have an unobstructed view of the water glass and
the steam gauge.
The vestibule cab is of the standard C.P.R. type, but owing to the width of fire box it prevented the placing of the brakeman's seat
in front of the fireman, as is generally the case. The cab is amply provided with wood lined lockers for the crew's clothes, etc. Signal
equipment is carried in a special wire rack located on the ceiling of the cab.
Standard C.P.R. Tender
The tender is of the water bottom type. The tank, which has a water carrying capacity of 8,000 Imperial gallons, is supported on a
Commonwealth one-piece cast steel underframe. The coal space provides for a capacity of 12 tons, and the 45 degree slope of the back
sheet insures a constant feed of coal to the front of the coal space, this feature dispensing with the use of a coal pusher. This is
standard practice in C.P.R. tender construction. The swash plate bracing is arranged to minimize rivet strain.
Air Brake and Special Equipment
The air brake is the Westinghouse schedule "ET" with cross compound compressors. Ample cooling surface is provided in the
air brake piping, 2-inch pipes being used between the compressor and the first reservoir. A parasite reservoir is also part of the air
system, and the pressure is controlled by a Westinghouse parasite governor.
The locomotives have a total weight of 320,500 pounds, with 235,000 pounds on the driving wheels, which gives a factor of adhesion of
4.18. The cylinders are 25 inches by 32 inches, driving wheels 63 inches in diameter, which, with a normal boiler pressure of 200
pounds per square inch, gives a maximum calculated tractive effort of 56,000 pounds.
The locomotives are hand-fired and have proved exceptionally good steamers, and quite live up to the expectations of economy in coal
The Vaughan-Horsey superheater, which has been giving excellent results in both passenger and freight locomotive service on the
Canadian Pacific Railway, is fairly familiar to those who have attended the mechanical conventions at Atlantic City. Mr. H.H. Vaughan,
assistant to the vice-president of this road has submitted very useful and interesting data on superheater works, and the appliance as
shown in the accompanying drawings was designed jointly by Mr. Vaughan and Mr. Horsey, mechanical engineer.
The records made by locomotives equipped with this superheater have been published often and the fact that almost all Canadian
Pacific engines either are already equipped, or are being equipped with it, is a strong point in its favor. The description as given by
Mr. Vaughan is as follows:
The superheater consists of two headers as shown in Figure 1, the upper of which is known as the saturated and the lower as the
superheated header. The steam from the throttle enters at "A" and passes downwards through the extensions on this header and
is distributed through the two and four way fittings shown in Figure 2, to the bent pipes which connect to the headers by union nuts as
shown, Figure 3, and extend backwards into the boiler flues which are 5 inches in diameter to a point about 20 inches from back flue
sheet. These tubes have return bends at the end near the firebox flue sheet and the steam, returning, enters the superheated steam
header. The superheating is thus done by the passage of the steam against and with the flow of gases from the firebox.
On the design shown in Figure 1 there are ninety-six pipes or forty-eight superheating elements, the combined capacity of which is
sufficient to superheat all of the steam admitted through the throttle and dry pipe. The steam after passing through the superheater
pipes and entering the superheated header is carried through the two steam pipes at "B" to the cylinders.
The arrangement of the plating in the smokebox is such that the passage of hot gases from the firebox may be cut off through the
5 inch flues in which are located the superheater tubes. This is necessary when the throttle is closed as there being no steam in the
pipes they would burn out, and the superheater damper cylinder, Figure 4, has been applied and connected to a damper in such a way that
steam being admitted to it while the throttle is open, opens the damper, permitting the passage of gases through the 5 inch flues, but
when the throttle is closed the counter weight at "C" (Fig. 1.) closes the damper and shuts off the draft, which is then
necessary through only the lower flues.
Rotary Snow Plows
January to December 1913
Canadian Pacific Railway rotary number 400811 at Revelstoke, British Columbia - 13 Jun 1940 Photographer unknown - Bud Laws
The development of the rotary snow plow has been chiefly due to Canadians and Canadian railways. This might be invidiously explained
by the amount of snow which is supposed to fall in Canada, although as a matter of fact the difficulties experienced in dealing with
snow are just as great on most of the roads crossing the Rocky and the Cascade Mountains in the United States as they are on those in
In both countries the rotary snow plow has been extensively used during the past twenty years, and it has proved so far to be the
only effective appliance for dealing with deep drifts and snow slides that were beyond the capacity of the wedge or ordinary snow plow.
The latter is still used extensively, and for drifts of moderate depth through which a reasonable speed can be maintained, it can be
operated much more quickly than the rotary. When cuts are too deep, snow cannot be thrown out of them with a wedge plow, and in the case
of slides the drift may contain rocks or trees, which would make the use of it exceedingly dangerous. The rotary plow can then be used
to save the labor of shoveling out by hand, which would be the only resource, on account of its ability to encounter snow of any depth
and throw it to a considerable distance on either side of the track.
The rotary snow plow was originally invented by J.W. Elliott, a dentist of Toronto, who in 1869 took out a patent on a "compound
revolving snow shovel". This invention employed a wheel having a number of flat arms supported on a shaft rotating in line with the
track. The wheel was enclosed in a casing shaped at the forward end to collect the snow, and flaring backwards to a cylindrical portion
surrounding the wheel. This casing was open at the top to permit the snow being thrown out by the centrifugal force. The wheel was
driven by a rotary engine, and while the design was obviously crude, it evidently included the principal elements of the modern plow. No
practical use was, however, made of this invention, but the idea was later taken up by Jull, who improved the Elliott wheel by placing a
knife or cutting wheel in front of it. This knife wheel was intended to cut the snow from the bank and pass it into the fan wheel behind
it, by which it could be discharged through the top of the casing.
The Jull invention was taken up by the Leslie Brothers, of Orangeville, Ontario, who proceeded to construct a full-size working
model. The fan wheel was mounted on a hollow shaft, the knife wheel being carried on a solid shaft which passed through it. Both shafts
were revolved in opposite directions through a system of bevel gears driven by a two-cylinder engine. The first working model of this
plow was erected on the end of a flat car during the winter of 1883-84 at the Canadian Pacific Railway shops at Parkdale, but before its
construction was completed, the winter was practically over. In order to test the invention, a bank of snow and ice was shoveled into a
cut through which the Canadian Pacific tracks ran between Queens Wharf and Parkdale. The quantity available was limited, but it was
clearly demonstrated that the Elliott principle of a revolving wheel could throw the snow clear of the tracks, as both snow and ice were
thrown over 200 feet. This preliminary trial also showed that it was necessary for the plow to be so constructed that snow could be
thrown on either side of the track, and that a flanger was required to prevent the plow being derailed in hard snow or ice and leave a
satisfactory rail after it has passed through. With the Jull knife the direction in which the snow was thrown could not be changed as
the wheel could only operate in one direction, and the opening in the top of the casing was fixed in position. The Leslie Brothers then
developed a wheel with reversible knife or cutters, which could be changed in position to enable them to cut in either direction and a
movable hood on the cylindrical portion of the casing through which the snow could be discharged on either side of the track. They also
devised a suitable flanger or ice cutter, which was attached to the front truck of the plow.
A full-sized complete plow of this design was constructed for them by the Cook Locomotive Works, of Paterson, New Jersey, USA, and
was operated on the lines of the Chicago & North Western Railway in Northern Iowa in 1885-1886. It was then found that the principle
of employing two wheels revolving in opposite directions was impracticable, as the friction caused by the snow passing between the
wheels absorbed more power than that actually required to cut away and throw the snow. It consequently had to be abandoned, but the
Leslies then devised a single wheel having knives or cutters directly attached to it, which automatically reversed in position according
to the direction in which the wheel revolved. The plow with this wheel applied was tested during the same winter before the snow had
entirely disappeared, and proved that the loss of power was overcome. It was then shipped back to Paterson, and rebuilt with the
improvements that had been suggested by the season's experience. During the following winter, that of 1886-1887, the improved plow, then
known as the "Rotary", was given its first trial on the Oregon Short Line division of the Union Pacific, where it proved such
a complete success that the railway company not only purchased it after its first trip, but placed orders for three more of the same
pattern to be furnished in time for the following winter.
The introduction of the rotary progressed rapidly from that date. They were adopted by the Northern Pacific, Chicago & North
Western, Chicago Milwaukee & St. Paul, and many other roads in the United States, while in Canada eight were constructed by the
Canadian Pacific Railway in 1888 at their Montreal shops through the Polson Iron Works Company, of Toronto. The first of these plows,
No. 101, had a wheel 9 feet 10 1/2 inches in diameter, a boiler having 1,259 square feet of heating surface carrying 180 pounds
pressure, and a two-cylinder engine 17 inches diameter by 24 inch stroke. The cab was of wood, a point of weakness on account of the
heavy bending strain to which it was subjected when the lower portion of the casing was forced into hard snow. The side frame, which was
a heavy 12-inch channel running from end to end, was tied together by the main bearing casting and engine shaft casting at the front and
end from the latter, two inner frames extended to the back end. These supported the cylinder, saddle and the boiler carriers, and were
connected to the side frames by gusset plates. The structure was fairly strong longitudinally, but as later experience proved it did not
possess the necessary vertical strength for the work it was subjected to.
The wheel with which these plows were fitted was known as the square fan type. The back was a sheet of steel plate to which
longitudinal gusset plates or partitions were attached, which in their turn supported the front rings and the trunnions for the knives
or cutters. The action of these knives can be readily understood. In whichever direction the plow was turning the resistance of the snow
would tend to force the knives into a position in, which they would cut the snow, and deliver it into the compartments. Then, on account
of the centrifugal force due to the revolving wheel, it would be forced against the casing until the opening was reached, when it would
fly out in a straight line. This wheel proved satisfactory when handling the dry snow found east of the Rockies, but in heavy work the
partitions were not sufficiently strong to drive the knives. As the men on the plows put it, "The back ran away from the
front". To overcome this and handle the damp snow found on the western slopes, the Leslie Brothers introduced the scoop wheel shown
in Figure 1. In this wheel the pockets or compartments are conical-shaped scoops strongly secured to a cast iron or cast steel center.
The knives are carried on the edges of the scoops, and the knives on the adjacent edges of each pair of scoops are connected together by
links so that as one knife is cutting the snow, the other is pressed down to afford the necessary clearances. This style of wheel
entirely superseded the older square fan type and has since been used.
Fig. 1 - Scoop wheel.
The construction of the plow as a whole has not changed radically with the exception of the special plows which will be described
later. The wheel has been increased in diameter, 11 feet being now the usual size. The engine and boiler capacity have been increased,
the engine to 18 inches diameter by 26 inches stroke, the boiler to 200 lbs. pressure with 1,852 square feet of heating surface. The
bevel gear drive was changed to employ two bevel pinions with independent engine shafts, the bevel gears and pinions being made of steel
with cut teeth in place of the cast iron gears originally used. The knives which were originally made of steel plate were greatly
increased in strength and made of cast steel. Cut wideners were added to the casing to enable the banks to be cut away and the strength
of the casing greatly increased, especially at the cutting edges. Figure 2 shows the construction of the casing, and attention is called
to the flatness of the surfaces at the corners, which give trouble on account of ice forming there when the plow is forced into the
snow. A plow was constructed for the Canadian Pacific Railway in 1911, to which cut wideners were applied, which when not required can
be folded back against the sides of the casing, the rods which hold them in position being then removed.
Fig. 2 - Plow casing.
The development which has taken place in the rotary snow plow has, without any question, proved that this is the only successful plow
of its type and, the means by which trains have been operated during severe winter weather. It is difficult to imagine how the railroads
of the United States and Canada could have operated without it with the amount of traffic they are now called upon to handle. There have
been many attempts to develop other styles of steam-driven plows, but none have been found as powerful and efficient as the rotary, and
none are today in actual use. The experience on the Canadian Pacific Railway showed, however, in the opinion of its officers that good
as the rotary was, it was not good enough. It is only fair to Mr. Leslie to say that he does not agree that the rotary was properly
operated on the Canadian Pacific Railway, and to a great extent his opinion is no doubt correct. On the other hand, the heaviest service
a plow is subjected to is when cutting its way through snow slides, and unfortunately these are met with on every road that operates to
the Pacific Coast. The snow in a slide is not only packed exceedingly hard, but it is liable to contain trees and rocks which are
carried with it down the mountain side. No plow can, of course, handle such obstructions and when they are discovered they are either
pulled out or blasted away. There is. however, a very strong pressure on every railroad at the present day to open up the line in the
shortest possible time, and to effect this the usual method of operating a rotary was to put two heavy engines behind it, run the plow
engine as fast as possible and drive it into the cut at 8 or 10 miles an hour. As the plow slowed down it was drawn back, speeded up
again, and the operation repeated. If trees or rocks were met with the knives were frequently torn off or damaged and their repair was
an extremely difficult and tedious job.
In addition, two points that have been referred to, the formation of ice in the casing and the weakness of the plow frame, were a
constant source of trouble, apart from the time that was taken to clean out a cut of any length.
During the winter of 1908-1909 G.J. Bury, then general manager of the Canadian Pacific Western lines, was engaged for a considerable
time in operating rotary plows, and decided that a plow was required that practically could not break down and that would have
sufficient power and strength to cut its way through any snow bank. His instructions were that he wanted a plow with knives of two inch
armor plate and the rest in proportion. Authority was given the following spring for two plows to these specifications and arrangements
were made with the Montreal Locomotive Works for their construction. John Player, consulting engineer of the American Locomotive
Company, was engaged to prepare the design in collaboration with the writer, and it was decided to modify the construction of the
regular rotary plows considerably. The writer had for some years believed that better results could be obtained by driving the plow
wheel direct in marine engine style than through the bevel gears previously used, and that the frame of the plow should resemble a
bridge girder to thoroughly support the casing or hood in place of the channel iron frame which required bracing to prevent its
After some preliminary designs had been prepared it was decided to adopt these suggestions, and as the work progressed a number of
novel features of construction developed. One of the most important questions was that of obtaining a wheel of greatly increased
strength. The use of a knife blade two inches thick with a corresponding construction behind it would have led to a weight that was
impracticable, but the wheel as actually built is immensely strong and radically different from those previously employed. The
cone-shaped scoops, which have been illustrated, were formed from plates of 3/8 inch steel pressed into shape and the hinges for the
knife blades were riveted to their edges. To obtain the desired strength these plates would have to be increased to 1 1/4 inch or 1 1/2
inch, which would make them most difficult to form and necessitate the hinge castings being fitted to them individually as it could not
be expected they would be absolutely uniform in shape. It was therefore decided to make the entire wheel out of cast steel, casting the
hinges solid with the body of the wheel. As no machinery facilities or annealing furnaces were available for handling a casting of this
size in one piece, the center was made in octagon form. 80 inches across the flats, with 8 segments bolted to it. The faces at the
center were machined and hinge holes drilled. Stops were provided against which the blades bear when cutting. The hinges are 6 inches in
diameter at the largest part and the hinge pin 2 1/2 inches in diameter. The bottom holes in line with the hinge holes are for the 2 1/4
inch bolts which secured the segments to the center. There are three of these bolts in each segment, one in line with each hinge hole
and one central between the hinges. There are also 5 bolts, 2 inches in diameter through the flanges at their rear edges. It was
necessary to make the fastenings between the segments and the center of ample strength, not only to stand the shocks at the edge of the
blade, but the effect of centrifugal force which at 400 revolutions per minute, the estimated maximum speed, was equal to about 275
times the weight on a diameter of 11 feet.
Figure 3 is a view of the wheel assembled before the knives are attached. This view shows the band, 1 1/4 inch on each end, which fit
in grooves cut in the segments and is also securely bolted to them. It is increased in thickness to compensate for the holes for the
hinge pins and bolts. This view also shows the bolts attaching the segments to the center and the stops for the knife blades. The blades
are of massive construction and have three hinges ? thick by 10 inches wide, which further secures the segments in place. This band is
made in sections with L-shaped lug pins, 1 3/8 inch, 1 5/8 inch, and 2 1/4 inches in diameter respectively. The hinges on the wheel and
on the knives are sufficiently strong to bear these pins and it was calculated that to shear the outer pin, which is the one exposed to
the greatest strain would require 400 tons at the edge of the blade. The knives are 5/8 inch thick at the edge and heavily ribbed, while
the stop extends from end to end and forms a strong backbone.
Fig. 3 - Wheel before knives are attached.
The complete wheel was balanced at the shops without the nose pieces. In this condition it weighed 24,000 pounds and on account of
the high speed at which it was required to run it was necessary to balance it most accurately. Links were provided connecting each pair
of knives to move the rear knife into the proper position. The machined surface near the link was to permit of the attachment of clips
to hold the knives in their proper position, but these were not required when the proper length of link was obtained. A front view of
the wheel in place in the plow (figure 4) will clearly show the general strength of its design.
Fig. 4 - Wheel in place.
The casing of this wheel was made of 3/4 inch plate in two tapered courses, the front one being tapered 1 to 1 1/2, the back one 1
in 4. In place of making the front of the casing in a vertical plane, the taper course was cut away to bring its cross section to the
shape required. By adopting this plan all flat surfaces which might lead to the formation of ice were avoided. The front casing is
reinforced by a second thickness of 3/4 inch plate along its lower front edge, and heavily braced with tee irons. The back of the casing
is constructed of steel castings, having flanges for attachment to the gusset plates, which are securely riveted to the frame. This view
also shows the taper wheel fit of the main shaft which is 11 1/8 inches diameter and 12 feet 2 inches long over all. The front bearing
is 11 1/8 inches diameter by 28 inches long. Behind this is a marine type thrust bearing having 10 collars and a rear bearing 10 inches
diameter by 16 1/2 inches long. The thrust bearing was introduced on account of the conviction that the arrangements for taking the
thrust were inadequate on the older plows, and in their case the thrust was actually taken by the sheet of ice which formed between the
plow wheel and the casing. This has been justified by the results as the plow runs very freely on heavy cuts. On the rear end of the
main shaft is a crank disc connected to the crank pin of the engine by a drag link coupling. This was used in case of variation between
the alignment of the main shaft and the engine crank shaft and to prevent any bending strains being transmitted from one to the
On one plow there is actually a difference of 1/4 inch which is easily taken care of in this way. The engine is of strong but light
construction, the cylinders 20 inches diameter, 24-inch stroke, are of grey iron cast in one with the steam chest and bolted together.
The columns are of cast steel and their shape was carefully worked out. On account of head room the length of connecting rod is very
short in proportion to the stroke, only 1.87 to 1, which required ample bearing surface in the crossheads. This feature has, however,
given no trouble. The reverse lever and throttle are in duplicate, so that the plow may be operated from either side. On the casing is
the steady block arrangement. This comprised a shoe on either side of the casing which can be forced down on the rail to steady the plow
when taking heavy cuts. It is operated by an air cylinder, but this has not proved satisfactory and is to be changed to a hand
The frames arc box girders 36 inches deep at the front end, the outer plate being 3/8 inch thick, the inner 1/2 inch. The top and
bottom flanges are 13 inch ship channels and the frame is carried back full depth to the boiler saddle where it tapers down to 18 inches
deep at the back end. This view also shows the heavy steel front casting, the 3/4 inch plate which connects the frames together at the
bottom, and the shaft bearing and engine-supporting angles.
The engine crank pin in front is for the drag link, the pins are hollow and in many respects weight has been saved as much as
possible. The operating platform is supplied with the engineer's valve of the Westinghouse air brakes, and also the straight air brake
valve. Other valves control the flanger, ice cutters, and steadying blocks, all of which are operated by compressed air. Slides in the
center carry the bracket for the electric headlight, which can be lowered down into the cab when required.
The boiler applied to these plows is similar to that on the Canadian Pacific Class M-4 Consolidation locomotives, with the exception
that the superheater was omitted. It was thought that as the plows would only be used a few times each year the economy resulting from
superheating, was unimportant, while the possibility of the apparatus leaking or not being in perfect order when required would be
objectionable. The boiler contains 2,108 square feet of heating surface and 44 square feet of grate area, and carries 200 lbs. pressure.
It is, therefore, of far greater capacity than any previously employed on this class of work.
The trucks are of the six-wheel type, but of special design, having cast steel frames. The axles are the M.C.B. 50,000 pounds
standard with 7 inch by 12 inch journals, and the wheels 34 inches diameter with steel tyres. On account of the plow having no center
frames, but simply two main longitudinal girders, no weight is carried on the center plates, which are used simply to guide the trucks,
and the weight is carried on sliding surfaces located between the side frames of the trucks and the plow girders. On account of there
not being sufficient room, the usual type of truck equalizer could not be applied, and underhung equalizers are used which bear on pins
in lugs cast on the boxes. To save weight the end, pedestals are dispensed with and the frame is formed with guides, which engage with
grooves on the journal boxes. This design of truck is exceedingly light for its strength, and with certain exceptions that will be
referred to later, has proved satisfactory. Their size may be judged from, the frame being 48 feet, 4 inches long over all from the
casing to the rear end. They weigh 260,000 lbs. in working order, the weight being practically equal on the two trucks. The cab or
covering is of steel and is smooth inside, the angles and braces being on the outside to avoid injury to the men in case of
The tender attached to the plow has a capacity of 7,000 gallons of water, and 16 tons of coal. It was made specially long, 32 feet
over end frames, in order to separate the weight of the plow from the engines pushing it on account of bridge limitations. The tender
trucks are inside bearing four-wheel equalizer pedestal trucks, this design being adopted to use engine truck wheels and axles of
The design of these plows was commenced in July, 1910, and a considerable amount of preliminary work was required before it was
possible to decide on the general plan that would be practicable. In addition it was desired to apply the new type of wheel and casing
to several of the older plows in service, and in order to do this in time the design of the wheel had to be completed before the balance
of the work was taken up. About the 1st of October it was possible to prepare an estimate of the weight of the complete plow, when it
was found that it would greatly exceed the limits that had been allowed by the bridge department. The wheels which were constructed at
the Angus shops, were by that time partly completed, so that it was necessary to revise all the other drawings and practically redesign
the entire plow. In fact, there was hardly a pattern or a drawing that did not require making up anew, with the exception that the only
alteration of the boiler was to shorten the barrel. In spite of this delay, the first plow was completed by the Montreal Locomotive
Works on 8 Jan 1911, and the second one a few days later, a remarkably quick piece of work in view of its size and every part being
entirely new in design.
It is difficult to say whether these plows have proved entirely satisfactory in service. From the time they arrived in the mountains
there has been no trouble with snow that would test their capacity. They have been run through a drift of hard packed snow about 250
yards long without slowing down, and pushed by one engine in place of requiring two, as would have been the case with the old plows.
This indicates that they have ample power and steaming capacity. One of the Western officers of the Canadian Pacific states that they
will cut trees four inches diameter, but they have not been tried on anything heavier. Last season the man in charge, while going
through a cut, felt a jar and saw a car coupler which had been left in the drift, thrown out to one side. The only damage is reported to
have been a semicircular piece about 2 inches in diameter broken out of one of the blades. With these exceptions, it has been difficult
to obtain any definite reliable information. The plows do, however, work exceedingly well. There is an entire absence of the noise end
vibration which makes the operation of a bevel gear driven rotary so unpleasant. The plows are so strongly constructed that it is
difficult to see how any obstructions could injure them, and from what experience has been obtained, it is expected that they will be of
great assistance in keeping the road open under any conditions.
The only trouble that has been experienced is through derailment. When the track is badly heaved, one spring on an equalizer may be
compressed until practically solid and thus change the actual fulcrum of the equalizer. This has been overcome by placing a seat between
the springs and the equalizer to ensure a constant point of application of the load and placing springs between the truck frame and the
supporting plates. These were required on account of the small amount the plow frame can be twisted. When supported on one side only the
opposite side was found to be 1/8 inch lower. This shows the stiffness of the frame construction and explains why additional spring
movement was necessary to compensate for the irregularities of the track.
While during the past few years the tendency has been to depend on wedge plows rather than rotaries for the general work of clearing
away snow, still the rotary is called on when the limit of the wedge plows is reached, and for work they cannot safely attempt. The
energy and perseverance of the Leslies led to the practical development of the rotary snow plow, aml they deserve a great deal of credit
for furnishing the railroads with a machine that has rendered winter operation possible.
By H.H. Vaughan
From a paper read before the Canadian Society of Civil Engineers.
Canadian Pacific Ten-Wheeler
New York, November, 1898.
The ten-wheel engine here shown was recently built at the Canadian Pacific Railway shops at Montreal for fast heavy passenger
service. The engine is compound, after the Pittsburg system, and has a total weight of 126,000 pounds, of which 96,000 rest on the
The cylinders are 19 and 29 inches diameter, with 24 inch stroke. The driving wheels arc 62 inches diameter, and have cast-iron
centers. The driving axle journals are 8 x 8 1/2 inches, and the truck journals 5 x 8 inches. The main pin is 6 x 6 inches. The steam
ports of the high-pressure cylinder are 20 inches long, and of the low-pressure cylinder 21 inches. The width of the ports is 1 3/4
inches for the high-pressure side, and 2 inches for the low pressure. The widths of the exhaust ports are 3 inches for high pressure and
3 1/2 inches for low pressure. The bridges on the high-pressure cylinder are 1 1/8 inches, and on the low pressure 1 1/4 inches
diameter. The valves are Morse balanced, and on the high-pressure side have a travel of 5 1/2 inches, while on the low-pressure side the
travel is 6 inches. The lap of the valves is 7/8 inch, and there is 3/8 inch inside clearance.
The boiler is the Belpaire type, with conical connection and wagon top, and is designed to carry working pressure of 200 pounds per
square inch. The material is steel 9/16 inch thick, and the diameter of boiler outside of waist is 53 3/4 inches. The horizontal seams
are double riveted with safety rows and inside and outside welts. The circumferential seams are double riveted. The crown sheet is
supported by direct stays.
The firebox is 96 1/2 inches long inside, 42 5/8 inches wide, 60 1/4 inches deep in front, and 45 3/4 inches deep in the back. The
tubes are all charcoal iron, and are 216 in number, 2 inches diameter. All the rest of the boiler is steel. The tubes are 11 feet 8 7/16
inches long. The tubes provide 1,320 square feet of heating surface, and the firebox 120 square feet, making a total of 1,440 square
feet. The grate area is 28.6 square feet.
Among the special equipment to be noted on the engine are the Westinghouse American brake, with 9 1/2 inch Westinghouse pump. The
Westinghouse air signal is also used. There are Nathan sight-feed lubricators and Gresham & Craven injectors. United States metallic
packing is used for valve stems and piston rods. There are Krupp tires, Leach sanding apparatus, and Crosby steam gages. The heating
apparatus is a consolidated Commingler system.