THE WESTINGHOUSE BRAKE.
In March, 1825, there appeared in the pages of the _Quarterly
Review_ an article in which the writer discussed that railway
system, the first vague anticipation of which was then just
beginning to make the world restless. He did this, too, in a very
intelligent and progressive spirit, but unfortunately secured for
his article a permanence of interest he little expected by the
use of one striking illustration. He was peculiarly anxious to
draw a distinct line of demarcation between his own very rational
anticipations and the visionary dreams of those enthusiasts who
were boring the world to death over the impossibilities which they
claimed that the new invention was to work. Among these he referred
to the proposition that passengers would be "whirled at the rate
of eighteen or twenty miles an hour by means of a high pressure
engine," and then contemptuously added,--"We should as soon expect
the people of Woolwich to suffer themselves to be fired off upon one
of Congreve's _ricochet_ rockets, as trust themselves to the mercy
of such a machine, going at such a rate; their property perhaps they
may trust."
Under the circumstances, the criticism was a perfectly reasonable
one. The danger involved in going at such a rate of speed and the
impossibility of stopping in time to avoid a sudden danger, would
naturally suggest themselves to any one as insuperable objections
to the new system for any practical use. Some means of preserving
a sudden and powerful control over a movement of such unheard of
rapidity would almost as a matter of course be looked upon as a
condition precedent. Yet it is a most noticeable fact in the history
of railroad development that the improvement in appliances for
controlling speed by no means kept pace with the increased rate of
speed attained. Indeed, so far as the possibility of rapid motion
is concerned, there is no reason to suppose that the _Rocket_
could not have held its own very respectably by the side of a
passenger locomotive of the present day. It will be remembered
that on the occasion of the Manchester & Liverpool opening, Mr.
Huskisson after receiving his fatal injury was carried seventeen
miles in twenty-five minutes. Since then the details of locomotive
construction have been simplified and improved upon, but no great
change has been or probably will be effected in the matter of
velocity;--as respects that the maximum was practically reached
at once. Yet down to the year 1870 the brake system remained very
much what it was in 1830. Improvements in detail were effected,
but the essential principles were the same. In case of any sudden
emergency, the men in charge of the locomotive had no direct control
over the vehicles in the train; they communicated with them by the
whistle, and when the signal was heard the brakes were applied as
soon as might be. When a train is moving at the rate of forty miles
an hour, by no means a great speed for it while in full motion, it
passes over fifty-eight feet each second;--at sixty miles an hour it
passes over eighty-eight feet. Under these circumstances, supposing
an engine driver to become suddenly aware of an obstruction on the
track, as was the case at Revere, or of something wrong in the train
behind him, as at Shipton, he had first himself to signal danger,
and to this signal the brakemen throughout the train had to respond.
Each operation required time, and every second of time represented
many feet of space. It was small matter for surprise, therefore,
that when in 1875 they experimented scientifically in England, it
was ascertained that a train of a locomotive and thirteen cars
moving at a speed of forty-five miles an hour could not be brought
to a stand in less than one minute, or before it had traversed a
distance of half a mile. The same result it will be remembered was
arrived at by practical experience in America, where both at Angola
and at Port Jervis,[22] it was found impossible to stop the trains
in less than half-a-mile, though in each case two derailed cars were
dragging and plunging along at the end of them.
[22] _Ante_, pp. 15, 119.
The need of a continuous train-brake, operated from the locomotive
and under the immediate control of the engine-driver, had been
emphasized through years by the almost regular recurrence of
accidents of the most appalling character. In answer to this need
almost innumerable appliances had been patented and experimented
with both in Europe and in America. Prior to 1869, however,
these had been almost exclusively what are known as emergency
brakes;--that is, although the trains were equipped with them and
they were operated from the locomotives, they were not relied upon
for ordinary use, but were held in reserve, as it were, against
special exigencies. The Hudson River railroad train at the Hamburg
accident was thus equipped. Practically, appliances which in the
operation of railroads are reserved for emergencies are usually
found of little value when the emergency occurs. Accordingly no
continuous brake had, prior to the development of Westinghouse's
invention, worked its way into general use. Patent brakes had
become a proverb as well as a terror among railroad mechanics,
and they had ceased to believe that any really desirable thing of
the sort would ever be perfected. Westinghouse, therefore, had a
most unbelieving audience to encounter, and his invention had to
fight hard for all the favor it won; nor did his experience with
master mechanics differ, probably, much from Miller's. His first
patents were taken out in 1869, and he early secured the powerful
aid of the Pennsylvania road for his invention. The Pullman Car
Company, also, always anxious to avail themselves of every appliance
of safety as well as of comfort, speedily saw the merits of the
new brake and adopted it; but, as they merely furnished cars and
had nothing to do with the locomotives that pulled them, their
support was not so effective as that of the great railroad company.
Naturally enough, also, great hesitation was felt in adopting so
complicated an appliance. It added yet another whole apparatus to
a thing which was already overburdened with machinery. There was,
also, something in the delicacy and precision of the parts of this
new contrivance,--in its air-pump and reservoirs and long connecting
tubes with their numerous valves,--which was peculiarly distasteful
to the average practical railroad mechanic. It was true that the
idea of transmitting power by means of compressed air was by no
means new,--that thousands of drills were being daily driven by
it wherever tunnelling was going on or miners were at work,--yet
the application of this familiar power to the wheels of a railroad
train seemed no less novel than it was bold. It was, in the first
place, evident that the new apparatus would not stand the banging
and hammering to which the old-fashioned hand-brake might safely
be subjected; not indeed without deranging that simple appliance,
but without incurring any very heavy bill for repairs in so doing.
Accordingly the new brake was at first carelessly examined and
patronizingly pushed aside as a pretty toy,--nice in theory no
doubt, but wholly unfitted for rough, every-day use. As it was
tersely expressed during a discussion before the Society of Arts
in London, as recently as May, 1877,--"It was no use bringing out
a brake which could not be managed by ordinary officials,--which
was so wonderfully clever that those who had to use it could not
understand it." A line of argument by the way, which, as has been
already pointed out, may with far greater force be applied to the
locomotive itself; and, indeed, unquestionably was so applied
about half a century ago by men of the same calibre who apply it
now, to the intense weariness and discouragement no doubt of the
late George Stephenson. Whether sound or otherwise, however, few
more effective arguments against an appliance can be advanced; and
against the Westinghouse brake it was advanced so effectively,
that even as late as 1871, although largely in use on western
roads, it had found its way into Massachusetts only as an ingenious
device of doubtful merit. It was in August, 1871, that the Revere
disaster occurred, and the Revere disaster, as has been seen,
would unquestionably have been averted had the colliding train
been provided with proper brake power. This at last called serious
attention there to the new appliance. Even then, however, the mere
suggestion of something better being in existence than the venerable
hand-brakes in familiar use did not pass without a vigorous protest;
and at the meeting of railroad officials, which has already been
referred to as having been called by the state commissioners
after the accident, one prominent gentleman, when asked if the
road under his charge was equipped with the most approved brake,
indignantly replied that it was,--that it was equipped with the
good, old-fashioned hand-brake;--and he then proceeded to vehemently
stake his professional reputation on the absolute superiority of
that ancient but somewhat crude appliance over anything else of the
sort in existence. Nevertheless, on this occasion also, the great
dynamic force which is ever latent in first-class railroad accidents
again asserted itself. Even the most opinionated of professional
railroad men, emphatically as he might in public deny it, quietly
yielded as soon as might be. In a surprisingly short time after the
exhibition of ignorance which has been referred to, the railroads in
Massachusetts, as it has already been shown, were all equipped with
train-brakes.[23]
[23] Page 157.
In its present improved shape it is safe to say that in all those
requisites which the highest authorities known on the subject have
laid down as essential to a model train brake, the Westinghouse
stands easily first among the many inventions of the kind. It is
now a much more perfect appliance than it was in 1871, for it was
then simply atmospheric and continuous in its action, whereas it
has since been made automatic and self-regulating. So far as its
fundamental principle is concerned, that is too generally understood
to call for explanation. By means of an air-pump, attached to the
boiler of the locomotive and controlled by the engine-driver, an
atmospheric force is brought to bear, through tubes running under
the cars, upon the break blocks, pressing them against the wheels.
The hand of the engine-driver is in fact on every wheel in the
train. This application of power, though unquestionably ingenious
and, like all good things, most simple and obvious when once
pointed out, was originally open to one great objection, which was
persistently and with great force urged against it. The parts of the
apparatus were all delicate, and some injury or derangement of them
was always possible, and sometimes inevitable. The chief advantage
claimed for the brake was, however, that complete dependence could
be placed upon it in the regular movement of trains. It was obvious,
therefore, that if such dependence was placed upon it and any
derangement did occur, the first intimation those in charge of the
train would have that something was wrong might well come in the
shape of a failure of the brake to act, and a subsequent disaster.
Both in Massachusetts and in Connecticut, at the crossing of one
railroad by another at the same level in the former state and in the
approach to draws in bridges in the latter, a number of cases of
this failure of the original Westinghouse non-automatic brake to act
did in point of fact occur. Fortunately they, none of them, resulted
in disaster. This, however, was mere good luck, as was illustrated
in the case of the accident of November 11, 1876, at the Communipaw
Ferry on the New Jersey Central. The train was there equipped with
the ordinary train brake. It reached Jersey City on time shortly
after 4 P.M., but, instead of slacking up, it ran directly through
the station and freight offices, carrying away the walls and
supports, and the locomotive then plunged into the river beyond.
The baggage and smoking car followed but fortunately lodged on the
locomotive, thus blocking the remainder of the train. Fortunately no
one was killed, and no passengers were seriously injured.
Again, on the Metropolitan Elevated railroad in New York city, on
the evening of June 23, 1879, one of the trains was delayed for a
few moments at the Franklin street station. Meanwhile the next train
came along, and, though the engine-driver of this following train
saw the danger signals and endeavored to stop in time, he found his
brake out of order, and a collision ensued resulting in the injury
of one employé and the severe shattering of a passenger coach and
locomotive. It was only a piece of good fortune that the first
of these accidents did not result in a repetition of the Norwalk
disaster and the second in that of Revere.
It so chanced that it was the Smith vacuum brake which failed to
work at Communipaw, and the Eames vacuum which failed to work at
Franklin street. This, however, was wholly immaterial. It might just
as well have been the original Westinghouse. The difficulty lay, not
in the maker's name, but in the imperfect action of the brake; and
such significant intimations are not to be disregarded. The chances
are naturally large that the failure of the continuous brake to act
will not at once occur under just those circumstances which will
entail a serious disaster and heavy loss of life; that, however, if
such intimations as these are disregarded, it will sooner or later
so occur does not admit of doubt.
But the possibility that upon some given occasion it might fail to
work was not the only defect in the original Westinghouse; it might
well be in perfect order and in full action even, and then suddenly,
as the result of derailment or separation of parts, the apparatus
might be broken, and at once the shoes would drop from the wheels,
and the vehicles of the disabled train would either press forward,
or, on an incline, stop and run backwards until their unchecked
momentum was exhausted. This appears to have been the case at
Wollaston, and contributed some of its most disastrous features to
that accident.
To obviate these defects Westinghouse in 1872 invented what he
termed a triple valve attachment, by means of which, if the
thing can be so expressed, his brake was made to always stand at
danger. That is, in case of any derangement of its parts, it was
automatically applied and the train stopped. The action of the brake
was thus made to give notice of anything wrong anywhere in the
train. A noticeable case of this occurred on the Midland railway in
England, when on the November 22, 1876, as the Scotch express was
approaching the Heeley station, at a speed of some sixty miles an
hour, the hind-guard felt the automatic brake suddenly self-applied.
The forward truck of a Pullman car in the middle of the train had
left the rails; the front part of the train broke the couplings
and went on, while the rear carriages, acted upon by the automatic
brakes, came to a stand immediately behind the Pullman, which
finally rested on its side across the opposite track. There was
no loss of life. On the other hand, as the Scotch express on the
North Eastern road was approaching Morpeth, on March 25, 1877, at
a speed of some twenty-five miles an hour, the locomotive for some
reason left the track. The train was not equipped with an automatic
brake, and the carriages in it accordingly pressed forward upon
each other until three of them were so utterly destroyed as to be
indistinguishable. Five passengers lost their lives; the remains of
one of whom, together with the wheels of a carriage, were afterwards
taken out from the tank of the tender, into which they had been
driven by the force of the shock.
The theoretical objection to the automatic brake is obvious. In
case of any derangement of its machinery it applies itself, and,
should these derangements be of frequent occurrence, the consequent
stoppage of trains would prove a great annoyance, if not a source
of serious danger. This objection is not sustained by practical
experience. The triple valve, so called, is the only complicated
portion of the automatic brake, and this valve is well protected
and not liable to get out of order.[24] Should it become deranged
it will stop the working of the brake on that car alone to which it
belongs; and it will become deranged so as to set the brake only
from causes which would render the non-automatic brake inoperative.
When anything of this sort occurs, it stops the train until the
defect is remedied. The returns made to the English Board of
Trade enable us to know just how frequently in actual and regular
service these stoppages occur, and what they amount to. Take, for
instance, the North Eastern and the Caledonian railways. Both use
the automatic brake. During the last six months of 1878 the first
ran 138,000 train miles with it, in the course of which there
were eight delays or stoppages of some three to five minutes each
occasioned by the action of the triple-valve; being in round numbers
one occasion of delay in 17,000 miles of train movement. On the
Caledonian railway, during the same period, four brake failures, due
to the action of the triple-valve, were reported in runs aggregating
over 62,000 miles, being about one failure to 15,000 miles. These
failures moreover occasioned delays of only a few minutes each, and,
where the cause of the difficulty was not so immediately apparent
that it could at once be remedied, the brake-tubes of the vehicle
on which the difficulty occurred were disconnected, and the trains
went on.[25] One of these stoppages, however, resulted in a serious
accident. As a train on the Caledonian road was approaching the
Wemyss Bay junction on December 14th, in a dense fog, the engine
driver, seeing the signals at danger, undertook to apply his brake
slightly, when it went full on, stopping the train between the
distant and home signals, as they are called in the English block
system. After the danger signal was lowered, but before the brake
could be released, the signal-man allowed a following train to enter
upon the same block section, and a collision followed in which some
thirteen passengers were slightly injured. This accident, however,
as the inspecting officer of the Board of Trade very properly found,
was due not at all to the automatic brake, but to "carelessness
on the part of the signal-man, who disregarded the rules for the
working of the block telegraph instruments," and to the driver
of the colliding train, who "disobeyed the company's running
regulations." It gives an American, however, a realizing sense of
one of the difficulties under which those crowded British lines are
operated, to read that in this case the fog was "so thick that the
tail-lamp was not visible from an approaching train for more than a
few yards."
[24] Speaking of the modifications introduced into his brake by
Westinghouse since 1874, Mr. Thomas E. Harrison, civil engineer
of the North Eastern Railway Company in a communication to the
directors of that company of April 24, 1879, recommending the
adoption by it of the Westinghouse, and subsequently ordered to
be printed for the use of Parliament, thus referred to the triple
valve: "As the most important [of these modifications] I will
particularly draw your attention to the "triple-valve" which has
been made a regular bugbear by the opponents of the system, and has
been called complicated, delicate, and liable to get out of order,
etc. * * * It is, in fact, as simple a piece of mechanism as well
can be imagined, certain in its action, of durable materials, easily
accessible to an ordinary workman for examination or cleaning, and
there is nothing about it that can justify the term complication; on
the contrary, it is a model of ingenuity and simplicity."
[25] During the six months ending June 30, 1879, some 300 stops due
to some derangement of the apparatus of the Westinghouse brake were
reported by ten companies in runs aggregating about two million
miles. Being one stop to 6,600 miles run. Very many of these stops
were obviously due to the want of familiarity of the employés with
an apparatus new to them, but as a rule the delays occasioned did
not exceed a very few minutes; of 82 stoppages, for instance,
reported on the London, Brighton & South Coast road, the two longest
were ten minutes each and the remainder averaged some three or four
minutes.
After the application of the triple valve had made it automatic,
there remained but one further improvement necessary to render
the Westinghouse a well-nigh perfect brake. A superabundance of
self-acting power had been secured, but no provision was yet made
for graduating the use of that power so that it should be applied
in the exact degree, neither more nor less, which would soonest
stop the train. This for two reasons is mechanically a matter of
no little importance. As is well known a too severe application of
brakes, no matter of what kind they are, causes the wheels to stand
still and slide upon the rails. This is not only very injurious to
rolling stock, the wheels of which are flattened at the points which
slide, but, as has long been practically well-known to those whose
business it is to run locomotives, when once the wheels begin to
slide the retarding power of the brakes is seriously diminished.
In order, therefore, to secure the maximum of retarding power, the
pressure of the brake-blocks on the revolving wheels should be very
great when first applied, and just sufficient not to slide them; and
should then be diminished, _pari passu_ with the momentum of the
train, until it wholly stops. Familiar as all this has long been
to engine-drivers and practical railroad mechanics, yet it has not
been conceded in the results of many scientific inquiries. In the
report of one of the Royal Commissions on Accidents, for instance,
it was asserted that the momentum of a train was retarded more by
the action of sliding than of slowly revolving wheels; and again,
as recently as in May, 1877, in a scientific discussion in London
at one of the meetings of the Society of Arts, a gentleman, with
the letters C. E. appended to his name, ventured the surprising
assertion that "no brake could do more than skid the wheels of
a train, and all continuous brakes professed to do this, and he
believed did so about equally well." Now, what it is here asserted
no brake can do is exactly what the perfect brake will be made to
do,--and what Westinghouse's latest improvement, it is claimed,
enables his brake to do. It much more than "skids the wheels," by
measuring out exactly that degree of power necessary to hold the
wheels just short of the skidding point, and in this way always
exerts the maximum retarding force. This is brought about by means
of a contrivance which allows the air to leak out of the brake
cylinders so as to exactly proportion the pressure of the blocks
on the wheels to the speed with which the latter are revolving.
In other, and more scientific, language the force with which the
brake-blocks are pressed upon the wheels is made to adjust itself
automatically as the "coefficient of dynamic friction augments with
the reduction of train speed." It hardly needs to be said that in
this way the power of the brake is enormously increased.
In America the superiority of the Westinghouse over any other
description of train-brake has long been established through that
large preponderance of use which in such matters constitutes the
final and irreversible verdict.[26] In Europe, however, and
especially in Great Britain, ever since the Shipton-on-Cherwell
accident in 1874, the battle of the brakes, as it may not
inappropriately be called, has waxed hotter and hotter; and not only
has this battle been extremely interesting in a scientific way, but
it has been highly characteristic, and at times enlivened by touches
of human nature which were exceedingly amusing.
[26] In Massachusetts, for instance, where no official pressure
in favor of any particular brake was brought to bear, out of 473
locomotives equipped with train-brakes 361 have the Westinghouse,
which is also applied to 1,363 out of 1,669 cars. Of these, however,
79 locomotives and 358 cars are equipped with both the atmospheric
and the vacuum brakes.