plate between it and the main steam-valve, and worked by an
independent eccentric and rock-shaft. The upper arm of the rock-shaft
was curved so as to form a radius-arm, on which a sliding-block,
forming the termination of the upper valve-rod, could be adjusted and
held at varying distances from the axis, thus producing a variable
travel of the upper valve. This device did not give an absolutely
perfect cut-off, as it was not operative in backward gear, but when
running forward it would cut-off with great accuracy at any point of
the stroke, was quick in its movement, and economical in the
consumption of fuel.
After a short experience with this arrangement of the cut-off, the
partition plate was omitted, and the upper valve was made to slide
directly on the lower. This was eventually found objectionable,
however, as the lower valve would soon cut a hollow in the valve-face.
Several unsuccessful attempts were made to remedy this defect, by
making the lower valve of brass, with long bearings, and making the
valve-face of the cylinder of hardened steel; finally, however, the
plan of one valve on the other was abandoned, and recourse was again
had to an interposed partition plate, as in the original half-stroke
cut-off.
[Illustration: Fig. 11.--VARIABLE CUT-OFF ADJUSTMENT.]
Mr. Baldwin did not adopt this form of cut-off without some
modification of his own, and the modification in this instance
consisted of a peculiar device, patented September 13, 1853, for
raising and lowering the block on the radius-arm. A quadrant was
placed so that its circumference bore nearly against a curved arm
projecting down from the sliding-block, and which curved in the
reverse direction from the quadrant. Two steel straps side by side
were interposed between the quadrant and this curved arm. One of the
straps was connected to the lower end of the quadrant and the upper
end of the curved arm; the other, to the upper end of the quadrant and
the lower end of the curved arm. The effect was the same as if the
quadrant and arm geared into each other in any position by teeth, and
theoretically the block was kept steady in whatever position placed on
the radius-arm of the rock-shaft. This was the object sought to be
accomplished, and was stated in the specification of the patent as
follows:
"The principle of varying the cut-off by means of a vibrating arm
and sliding pivot-block has long been known, but the contrivances
for changing the position of the block upon the arm have been
very defective. The radius of motion of the link by which the
sliding-block is changed on the arm, and the radius of motion of
that part of the vibrating arm on which the block is placed,
have, in this kind of valve gear, as heretofore constructed, been
different, which produced a continual rubbing of the
sliding-block upon the arm while the arm is vibrating; and as the
block for the greater part of the time occupies one position on
the arm, and only has to be moved toward either extremity
occasionally, that part of the arm on which the block is most
used soon becomes so worn that the block is loose, and jars."
This method of varying the cut-off was first applied on the engine
"Belle," delivered to the Pennsylvania Railroad Company, December 6,
1854, and thereafter was for some time employed by Mr. Baldwin. It was
found, however, in practice, that the steel straps would stretch
sufficiently to allow them to buckle and break, and hence they were
soon abandoned, and chains substituted between the quadrant and curved
arm of the sliding-block. These chains in turn proved little better,
as they lengthened, allowing lost motion, or broke altogether, so that
eventually the quadrant was wholly abandoned, and recourse was finally
had to the lever and link for raising and lowering the sliding-block.
As thus arranged, the cut-off was substantially what was known as the
"Cuyahoga cut-off," as introduced by Mr. Ethan Rogers, of the Cuyahoga
Works, Cleveland, Ohio, except that Mr. Baldwin used a partition plate
between the upper and the lower valve.
But while Mr. Baldwin, in common with many other builders, was thus
resolutely opposing the link-motion, it was nevertheless rapidly
gaining favor with railroad managers. Engineers and master mechanics
were everywhere learning to admire its simplicity, and were
manifesting an enthusiastic preference for engines so constructed. At
length, therefore, he was forced to succumb; and the link was applied
to the "Pennsylvania," one of two engines completed for the Central
Railroad of Georgia, in February, 1854. The other engine of the order,
the "New Hampshire," had the variable cut-off, and Mr. Baldwin, while
yielding to the demand in the former engine, was undoubtedly sanguine
that the working of the latter would demonstrate the inferiority of
the new device. In this, however, he was disappointed, for in the
following year the same company ordered three more engines, on which
they specified the link-motion. In 1856, seventeen engines for nine
different companies had this form of valve gear, and its use was thus
incorporated in his practice. It was not, however, until 1857 that he
was induced to adopt it exclusively. This step was forced upon him, at
that time, by the report of Mr. Parry, then Superintendent of the
Works (now a member of the present firm), who, on returning from an
extended tour in the South, brought back the intelligence that the
link-motion was everywhere preferred, and that the Baldwin engines
were losing ground rapidly, in consequence of their lack of this
feature. Mr. Baldwin's characteristic reply was, "Then they shall have
link-motion hereafter." And thenceforth the independent cut-off
gradually disappeared, and the link reigned in its stead.
February 14, 1854, Mr. Baldwin and Mr. David Clark, Master Mechanic of
the Mine Hill Railroad, took out conjointly a patent for a feed-water
heater, placed at the base of a locomotive chimney, and consisting of
one large vertical flue, surrounded by a number of smaller ones. The
exhaust steam was discharged from the nozzles through the large
central flue, creating a draft of the products of combustion through
the smaller surrounding flues. The pumps forced the feed-water into
the chamber around these flues, whence it passed to the boiler by a
pipe from the back of the stack. This heater was applied on several
engines for the Mine Hill Railroad, and on a few for other roads; but
its use was exceptional, and lasted only for a year or two.
In December of the same year, Mr. Baldwin filed a caveat for a
variable exhaust, operated automatically, by the pressure of steam, so
as to close when the pressure was lowest in the boiler, and open with
the increase of pressure. The device was never put in service.
The use of coal, both bituminous and anthracite, as a fuel for
locomotives, had by this time become a practical success. The
economical combustion of bituminous coal, however, engaged
considerable attention. It was felt that much remained to be
accomplished in consuming the smoke and deriving the maximum of useful
effect from the fuel. Mr. Baird, who was now associated with Mr.
Baldwin in the management of the business, made this matter a subject
of careful study and investigation. An experiment was conducted under
his direction, by placing a sheet-iron deflector in the fire-box of an
engine on the Germantown and Norristown Railroad. The success of the
trial was such as to show conclusively that a more complete combustion
resulted. As, however, a deflector formed by a single plate of iron
would soon be destroyed by the action of the fire, Mr. Baird proposed
to use a water-leg projecting upward and backward from the front of
the fire-box under the flues. Drawings and a model of the device were
prepared, with a view of patenting it, but subsequently the intention
was abandoned, Mr. Baird concluding that a fire-brick arch as a
deflector to accomplish the same object was preferable. This was
accordingly tried on two locomotives built for the Pennsylvania
Railroad Company in 1854, and was found so valuable an appliance that
its use was at once established, and it was put on a number of engines
built for railroads in Cuba and elsewhere. For several years the
fire-bricks were supported on side plugs; but in 1858, in the "Media,"
built for the West Chester and Philadelphia Railroad Company,
water-pipes extending from the crown obliquely downward and curving to
the sides of the fire-box at the bottom, were successfully used for
the purpose.
The adoption of the link-motion may be regarded as the dividing line
between the present and the early and transitional stage of locomotive
practice. Changes since that event have been principally in matters of
detail, but it is the gradual perfection of these details which has
made the locomotive the symmetrical, efficient, and wonderfully
complete piece of mechanism it is to-day. In perfecting these minutiae,
the Baldwin Locomotive Works has borne its part, and it only remains
to state briefly its contributions in this direction.
The production of the establishment during the six years from 1855 to
1860, inclusive, was as follows: forty-seven engines in 1855;
fifty-nine in 1856; sixty-six in 1857; thirty-three in 1858; seventy
in 1859; and eighty-three in 1860. The greater number of these were of
the ordinary type, four drivers coupled, and a four-wheeled truck, and
varying in weight from fifteen ton engines, with cylinders twelve by
twenty-two, to twenty-seven ton engines, with cylinders sixteen by
twenty-four. A few ten-wheeled engines were built, as has been
previously noted, and the remainder were the Baldwin flexible-truck
six- and eight-wheels-connected engines. The demand for these, however,
was now rapidly falling off, the ten-wheeled and heavy "C" engines
taking their place, and by 1859 they ceased to be built, save in
exceptional cases, as for some foreign roads, from which orders for
this pattern were still occasionally received.
A few novelties characterizing the engines of this period may be
mentioned. Several engines built in 1855 had cross-flues placed in
the fire-box, under the crown, in order to increase the heating
surface. This feature, however, was found impracticable, and was soon
abandoned. The intense heat to which the flues were exposed converted
the water contained in them into highly superheated steam, which would
force its way out through the water around the fire-box with violent
ebullitions. Four engines were built for the Pennsylvania Railroad
Company, in 1856-57, with straight boilers and two domes. The "Delano"
grate, by means of which the coal was forced into the fire-box from
below, was applied on four ten-wheeled engines for the Cleveland and
Pittsburg Railroad, in 1857. In 1859, several engines were built with
the form of boiler introduced on the Cumberland Valley Railroad in
1851 by Mr. A. F. Smith, and which consisted of a combustion-chamber
in the waist of the boiler, next the fire-box. This form of boiler was
for some years thereafter largely used in engines for soft coal. It
was at first constructed with the "water-leg," which was a vertical
water-space, connecting the top and bottom sheets of the
combustion-chamber, but eventually this feature was omitted, and an
unobstructed combustion-chamber employed. Several engines were built
for the Philadelphia, Wilmington and Baltimore Railroad Company in
1859, and thereafter, with the "Dimpfel" boiler, in which the tubes
contain water, and, starting downward from the crown-sheet, are curved
to the horizontal, and terminate in a narrow water-space next the
smoke-box. The whole waist of the boiler, therefore, forms a
combustion-chamber, and the heat and gases, after passing for their
whole length along and around the tubes, emerge into the lower part of
the smoke-box.
In 1860, an engine was built for the Mine Hill Railroad, with boiler
of a peculiar form. The top sheets sloped upward from both ends toward
the centre, thus making a raised part or hump in the centre. The
engine was designed to work on heavy grades, and the object sought by
Mr. Wilder, the Superintendent of the Mine Hill Railroad, was to have
the water always at the same height in the space from which steam was
drawn, whether going up or down grade.
All these experiments are indicative of the interest then prevailing
upon the subject of coal-burning. The result of experience and study
had meantime satisfied Mr. Baldwin that to burn soft coal successfully
required no peculiar devices; that the ordinary form of boiler, with
plain fire-box, was right, with perhaps the addition of a fire-brick
deflector; and that the secret of the economical and successful use of
coal was in the mode of firing, rather than in a different form of
furnace.
The year 1861 witnessed a marked falling off in the production. The
breaking out of the war at first unsettled business, and by many it
was thought that railroad traffic would be so largely reduced that the
demand for locomotives must cease altogether. A large number of hands
were discharged from the works, and only forty locomotives were turned
out during the year. It was even seriously contemplated to turn the
resources of the establishment to the manufacture of shot and shell,
and other munitions of war, the belief being entertained that the
building of locomotives would have to be altogether suspended. So far,
however, was this from being the case, that, after the first
excitement had subsided, it was found that the demand for
transportation by the general government, and by the branches of trade
and production created by the war, was likely to tax the carrying
capacity of the principal Northern railroads to the fullest extent.
The government itself became a large purchaser of locomotives, and it
is noticeable, as indicating the increase of travel and freight
transportation, that heavier machines than had ever before been built
became the rule. Seventy-five engines were sent from the works in
1862; ninety-six in 1863; one hundred and thirty in 1864; and one
hundred and fifteen in 1865. During two years of this period, from
May, 1862, to June, 1864, thirty-three engines were built for the
United States Military Railroads. The demand from the various
coal-carrying roads in Pennsylvania and vicinity was particularly
active, and large numbers of ten-wheeled engines, and of the heaviest
eight-wheeled four-coupled engines, were built. Of the latter class,
the majority were with fifteen and sixteen inch cylinders, and of the
former, seventeen and eighteen inch cylinders.
The introduction of several important features in construction marks
this period. Early in 1861, four eighteen inch cylinder freight
locomotives, with six coupled wheels, fifty-two inches in diameter,
and a Bissell pony-truck with radius-bar in front, were sent to the
Louisville and Nashville Railroad Company. This was the first instance
of the use of the Bissell truck in the Baldwin Works. These engines,
however, were not of the regular "Mogul" type, as they were only
modifications of the ten-wheeler, the drivers retaining the same
position, well back, and a pair of pony-wheels on the Bissell plan
taking the place of the ordinary four-wheeled truck. Other engines of
the same pattern, but with eighteen and one-half inch cylinders, were
built in 1862-63, for the same company, and for the Don Pedro II.
Railway of Brazil.
The introduction of steel in locomotive-construction was a
distinguishing feature of the period. Steel tires were first used in
the works in 1863, on some engines for the Don Pedro II. Railway of
South America. Their general adoption on American railroads followed
slowly. No tires of this material were then made in this country, and
it was objected to their use that, as it took from sixty to ninety
days to import them, an engine, in case of a breakage of one of its
tires, might be laid up useless for several months. To obviate this
objection, M. W. Baldwin & Co. imported five hundred steel tires, most
of which were kept in stock, from which to fill orders.
Steel fire-boxes were first built for some engines for the
Pennsylvania Railroad Company in 1861. English steel, of a high
temper, was used, and at the first attempt the fire-boxes cracked in
fitting them in the boilers, and it became necessary to take them out
and substitute copper. American homogeneous cast-steel was then tried
on engines 231 and 232, completed for the Pennsylvania Railroad in
January, 1862, and it was found to work successfully. The fire-boxes
of nearly all engines thereafter built for that road were of this
material, and in 1866 its use for the purpose became general. It may
be added that while all steel sheets for fire-boxes or boilers are
required to be thoroughly annealed before delivery, those which are
flanged or worked in the process of boiler-construction are a second
time annealed before riveting.
Another feature of construction, gradually adopted, was the placing of
the cylinders horizontally. This was first done in the case of an
outside-connected engine, the "Ocmulgee," which was sent to the
Southwestern Railroad Company of Georgia in January, 1858. This engine
had a square smoke-box, and the cylinders were bolted horizontally to
its sides. The plan of casting the cylinder and half-saddle in one
piece and fitting it to the round smoke-box was introduced by Mr.
Baldwin, and grew naturally out of his original method of
construction. Mr. Baldwin was the first American builder to use an
outside cylinder, and he made it for his early engines with a circular
flange cast to it, by which it could be bolted to the boiler. The
cylinders were gradually brought lower, and at a less angle, and the
flanges prolonged and enlarged. In 1852, three six-wheels-connected
engines, for the Mine Hill Railroad Company, were built with the
cylinder flanges brought around under the smoke-box until they nearly
met, the space between them being filled with a spark-box. This was
practically equivalent to making the cylinder and half-saddle in one
casting. Subsequently, on other engines on which the spark-box was not
used, the half-saddles were cast so as almost to meet under the
smoke-box, and, after the cylinders were adjusted in position, wedges
were fitted in the interstices and the saddles bolted together. It was
finally discovered that the faces of the two half-saddles might be
planed and finished so that they could be bolted together and bring
the cylinders accurately in position, thus avoiding the troublesome
and tedious job of adjusting them by chipping and fitting to the
boiler and frames. With this method of construction, the cylinders
were placed at a less and less angle, until at length the truck-wheels
were spread sufficiently, on all new or modified classes of
locomotives in the Baldwin list, to admit of the cylinders being hung
horizontally, as is the present almost universal American practice. By
the year 1865, horizontal cylinders were made in all cases where the
patterns would allow it. The advantages of this arrangement are
manifestly in the interest of simplicity and economy, as the cylinders
are thus rights or lefts, indiscriminately, and a single pattern
answers for either side.
A distinguishing feature in the method of construction which
characterizes these Works, is the extensive use of a system of
standard gauges and templets, to which all work admitting of this
process is required to be made. The importance of this arrangement, in
securing absolute uniformity of essential parts in all engines of the
same class, is manifest, and with the increased production since 1861
it became a necessity as well as a decided advantage. It has already
been noted that as early as 1839 Mr. Baldwin felt the importance of
making all like parts of similar engines absolutely uniform and
interchangeable. It was not attempted to accomplish this object,
however, by means of a complete system of standard gauges, until many
years later. In 1861 a beginning was made of organizing all the
departments of manufacture upon this basis, and from it has since
grown an elaborate and perfected system, embracing all the essential
details of construction. An independent department of the Works,
having a separate foreman and an adequate force of skilled workmen,
with special tools adapted to the purpose, is organized as the
Department of Standard Gauges. A system of standard gauges and
templets for every description of work to be done, is made and kept by
this department. The original templets are kept as "standards," and
are never used on the work itself, but from them exact duplicates are
made, which are issued to the foremen of the various departments, and
to which all work is required to conform. The working gauges are
compared with the standards at regular intervals, and absolute
uniformity is thus maintained. The system is carried into every
possible important detail. Frames are planed and slotted to gauges,
and drilled to steel bushed templets. Cylinders are bored and planed,
and steam-ports, with valves and steam-chests, finished and fitted, to
gauges. Tires are bored, centres turned, axles finished, and
crossheads, guides, guide-bearers, pistons, connecting- and
parallel-rods planed, slotted, or finished, by the same method. Every
bolt about the engine is made to a gauge, and every hole drilled and
reamed to a templet. The result of the system is an absolute
uniformity and interchangeableness of parts in engines of the same
class, insuring to the purchaser the minimum cost of repairs, and
rendering possible, by the application of this method, the large
production which these Works have accomplished.