THE AUTOMATIC ELECTRIC BLOCK SYSTEM.
A realizing sense of the necessity of ultimately adopting some
system of protection against the danger of rear-end collisions was,
above all else, brought directly home to American railroad managers
through the Revere disaster. In discussing and comparing the
appliances used in the practical operation of railroads in different
countries, there is one element, however, which can never be left
out of the account. The intelligence, quickness of perception
and capacity for taking care of themselves--that combination of
qualities which, taken together, constitute individuality and
adaptability to circumstance--vary greatly among the railroad
employés of different countries. The American locomotive engineer,
as he is called, is especially gifted in this way. He can be relied
on to take care of himself and his train under circumstances which
in other countries would be thought to insure disaster. Volumes
on this point were included in the fact that though at the time
of the Revere disaster many of the American lines, especially in
Massachusetts, were crowded with the trains of a mixed traffic,
the necessity of making any provision against rear-end collisions,
further than by directing those in immediate charge of the trains
to keep a sharp look out and to obey their printed orders, seemed
hardly to have occurred to any one. The English block system was
now and then referred to in a vague, general way; but it was very
questionable whether one in ten of those referring to it knew
anything about it or had ever seen it in operation, much less
investigated it. A characteristic illustration of this was afforded
in the course of those official investigations which followed the
Revere disaster, and have already more than once been alluded to.
Prior to that disaster the railroads of Massachusetts had, as a
rule, enjoyed a rather exceptional freedom from accidents, and
there was every reason to suppose that their regulations were as
exact and their system as good as those in use in other parts of
the country. Yet it then appeared that in the rules of very few of
the Massachusetts roads had any provision, even of the simplest
character, been made as to the effect of telegraphic orders, or
the course to be pursued by employés in charge of trains on their
receipt. The appliances for securing intervals between following
trains were marked by a quaint simplicity. They were, indeed,
"singularly primitive," as the railroad commissioners on a
subsequent occasion described them, when it appeared that on one of
the principal roads of the state the interval between two closely
following trains was signalled to the engineer of the second train
by a station-master's holding up to him as he passed a number of
fingers corresponding to the number of minutes since the first
train had gone by. For the rest the examination revealed, as the
nearest approach to a block system, a queer collection of dials,
sand-glasses, green flags, colored lanterns and hand-targets. The
climax in the course of that investigation was, however, reached
when some reference, involving a description of it, was made to the
English block. This was met by a protest on the part of one veteran
superintendent, who announced that it might work well under certain
circumstances, but for himself he could not be responsible for the
operation of a road running the number of trains he had charge of in
reliance on any such system. The subject, in fact, was one of which
he knew absolutely nothing;--not even that, through the block system
and through it alone, fourteen trains were habitually and safely
moved under circumstances where he moved one. This occurred in 1871,
and though eight years have since elapsed information in regard
to the block system is not yet very widely disseminated inside of
railroad circles, much less outside of them. It is none the less
a necessity of the future. It has got to be understood, and, in
some form, it has got to be adopted; for even in America there are
limits to the reliance which, when the lives and limbs of many are
at stake, can be placed on the "sharp look out" of any class of men,
no matter how intelligent they may be.
The block system is of English origin, and it scarcely needs
to be said that it was adopted by the railroad corporations of
that country only when they were driven to it by the exigencies
of their traffic. But for that system, indeed, the most costly
portion of the tracks of the English roads must of necessity have
been duplicated years ago, as their traffic had fairly outgrown
those appliances of safety which have even to this time been found
sufficient in America. There were points, for instance, where two
hundred and seventy regular trains of one line alone passed daily.
On the London & North-Western there are more than sixty through
down trains, taking no account of local trains, each day passing
over the same line of tracks, among which are express trains which
stop nowhere, way trains which stop everywhere, express-freight,
way-freight, mineral trains and parcel trains. On the Midland road
there are nearly twice as many similar trains on each track. On the
Metropolitan railway the average interval is three and one-third
minutes between trains. In one case points were mentioned where
270 regular trains of one line alone passed a given junction
during each twenty-four hours,--where 470 trains passed a single
station, the regular interval between them being but five-eighths
of a mile,--where 132 trains entered and left a single station
during three hours of each evening every day, being one train in
eighty-two seconds. In 1870 there daily reached or left the six
stations of the Boston roads some 385 trains; while no less than
650 trains a day were in the same year received and despatched from
a single one of the London stations. On one single exceptional
occasion 1,111 trains, carrying 145,000 persons, were reported as
entering and leaving this station in the space of eighteen hours,
being rather more than a train a minute. Indeed it may well be
questioned whether the world anywhere else furnishes an illustration
so apt and dramatic of the great mechanical achievements of recent
times as that to be seen during the busy hours of any week-day from
the signal and interlocking galleries which span the tracks as
they enter the Charing Cross or Cannon street stations in London.
Below and in front of the galleries the trains glide to and fro,
coming suddenly into sight from beyond the bridges and as suddenly
disappearing,--winding swiftly in and out, and at times four of them
running side by side on as many tracks but in both directions,--the
whole making up a swiftly shifting maze of complex movement under
the influence of which a head unaccustomed to the sight grows
actually giddy. Yet it is all done so quietly and smoothly, with
such an absence of haste and nervousness on the part of the stolid
operators in charge, that it is not easy to decide which most to
wonder at, the almost inconceivable magnitude and despatch of the
train-movement or the perfection of the appliances which make it
possible. No man concerned in the larger management of railroads,
who has not passed a morning in those London galleries, knows what
it is to handle a great city's traffic.
Perfect as it is in its way, however, it may well be questioned
whether the block system as developed in England is likely to
be generally adopted on American railroads. Upon one or two of
them, and notably on the New Jersey Central and a division of the
Pennsylvania, it has already been in use for a number of years.
From an American point of view, however, it is open to a number
of objections. That in itself it is very perfect and has been
successfully elaborated so as to provide for almost every possible
contingency is proved by the results daily accomplished by means of
it.[13] The English lines are made to do an incredible amount of
work with comparative few accidents. The block system is, however,
none the less a very clumsy and complicated one, necessitating the
constant employment of a large number of skilled operators. Here
is the great defect in it from the American point of view. In this
country labor is scarce and capital costly. The effort is always
towards the perfecting of labor-saving machines. Hitherto the
pressure of traffic on the lines has not been greater than could
be fairly controlled by simpler appliances, and the expense of the
English system is so heavy that its adoption, except partially,
would not have been warranted. As Barry says in his treatise on the
subject, "one can 'buy gold too dear'; for if every possible known
precaution is to be taken, regardless of cost, it may not pay to
work a railway at all."
[13] An excellent popular description of this system will be found
in Barry's _Railway Appliances, Chapter V_.
It is tolerably safe, therefore, to predict that the American
block system of the future will be essentially different from the
present English system. The basis--electricity--will of course be
the same; but, while the operator is everywhere in the English
block, his place will be supplied to the utmost possible degree by
automatic action in the American. It is in this direction that the
whole movement since the Revere disaster has been going on, and
the advance has been very great. From peculiarities of condition
also the American block must be made to cover a multitude of weak
points in the operation of roads, and give timely notice of dangers
against which the English block provides only to a limited degree,
and always through the presence of yet other employés. For instance,
as will presently be seen, many more accidents and, in Europe even,
far greater loss of life is caused by locomotives coming in contact
with vehicles at points where highways cross railroad tracks at a
level therewith than by rear-end collisions; meanwhile throughout
America, even in the most crowded suburban neighborhoods, these
crossings are the rule, whereas in Europe they are the exception.
The English block affords protection against this danger by giving
electric notice to gatemen; but gatemen are always supposed. So
also as respects the movements of passengers in and about stations
in crossing tracks as they come to or leave the trains, or prepare
to take their places in them. The rule in Europe is that passenger
crossings at local stations are provided over or under the tracks;
in America, however, almost nowhere is any provision at all made,
but passengers, men, women and children, are left to scramble across
tracks as best they can in the face of passing trains. They are
expected to take care of themselves, and the success with which they
do it is most astonishing. Having been brought up to this self-care
all their lives, they do not, as would naturally be supposed, become
confused and stumble under the wheels of locomotives; and the
statistics seem to show that no more accidents from this cause occur
in America than in Europe. Nevertheless some provision is manifestly
desirable to notify employés as well as passengers that trains are
approaching, especially where way-stations are situated on curves.
Again, it is well known that, next to collisions, the greatest
source of danger to railroad trains is due to broken tracks. It
is, of course, apparent that tracks may at any time be broken by
accident, as by earth-slides, derailment or the fracture of rails.
This danger has to be otherwise provided for; the block has nothing
to do with it further than to prevent a train delayed by any such
break from being run into by any following train. The broken track
which the perfect block should give notice of is that where the
break is a necessary incident to the regular operation of the road.
It is these breaks which, both in America and elsewhere, are the
fruitful source of the great majority of railroad accidents, and
draw-bridges and switches, or facing points as they are termed in
the English reports, are most prominent among them. Wherever there
is a switch, the chances are that in the course of time there will
be an accident.
Four matters connected with train movement have now been specified,
in regard to which some provision is either necessary or highly
desirable: these are rear collisions, tracks broken at draw-bridges
or at switches, highway grade crossings, and the notification of
agents and passengers at stations. The effort in America, somewhat
in advance of that crowded condition of the lines which makes the
adoption of something a measure of present necessity, has been
directed towards the invention of an automatic system which at
one and the same time should cover all the dangers and provide
for all the needs which have been referred to, eliminating the
risks incident to human forgetfulness, drowsiness and weakness of
nerves. Can reliable automatic provision thus be made?--The English
authorities are of opinion that it cannot. They insist that "if
automatic arrangements be adopted, however suitable they may be to
the duties which they have to perform, they should in all cases be
used as additions to, and not as substitutions for, safety machinery
worked by competent signal-men. The signal-man should be bound to
exercise his observation, care and judgment, and to act thereon; and
the machine, as far as possible, be such that if he attempts to go
wrong it shall check him."
It certainly cannot be said that the American electrician has as
yet demonstrated the incorrectness of this conclusion, but he has
undoubtedly made a good deal of progress in that direction. Of the
various automatic blocks which have now been experimented with or
brought into practice, the Hall Electric and the Union Safety Signal
Company systems have been developed to a very marked degree of
perfection. They depend for their working on diametrically opposite
principles: the Hall signals being worked by means of an electric
circuit caused by the action of wheels moving on the rails, and
conveyed through the usual medium of wires; while, under the other
system, the wires being wholly dispensed with, a continuous electric
circuit is kept up by means of the rails, which are connected
for the purpose, and the signals are then acted upon through the
breaking of this normal circuit by the movement of locomotives and
cars. So far as the signals are concerned, there is no essential
difference between the two systems, except that Hall supplies the
necessary motive force by the direct action of electricity, while in
the other case dependence is placed upon suspended weights. Of the
two the Hall system is the oldest and most thoroughly elaborated,
having been compelled to pass through that long and useful tentative
process common to all inventions, during which they are regarded
as of doubtful utility and are gradually developed through a
succession of partial failures. So far as Hall's system is concerned
this period may now fairly be regarded as over, for it is in
established use on a number of the more crowded roads of the North,
and especially of New England, while the imperfections necessarily
incident to the development of an appliance at once so delicate and
so complicated, have for certain purposes been clearly overcome.
Its signal arrangements, for instance, to protect draw-bridges,
stations and grade-crossings are wholly distinct from its block
system, through which it provides against dangers from collision and
broken tracks. So far as draw-bridges are concerned, the protection
it affords is perfect. Not only is its interlocking apparatus so
designed that the opening of the draw blocks all approach to it,
but the signals are also reciprocal; and if through carelessness or
automatic derangement any train passes the block, the draw-tender is
notified at once of the fact in ample time to stop it.
In the case of a highway crossing at a level, the electric bell
under Hall's system is placed at the crossing, giving notice of
the approaching train from the moment it is within half a mile
until it passes; so that, where this appliance is in use, accidents
can happen only through the gross carelessness of those using the
highway. When the electric bell is silent there is no train within
half a mile and the crossing is safe; it is not safe while the bell
is ringing. As it now stands the law usually provides that the
prescribed signals, either bell or whistle, shall be given from the
locomotive as it approaches the highway, and at a fixed distance
from it. The signal, therefore, is given at a distance of several
hundred yards, more or less, from the point of danger. The electric
system improves on this by placing the signal directly at the point
of danger,--the traveller approaches the bell, instead of the bell
approaching the traveller. At any point of crossing which is really
dangerous,--that is at any crossing where trees or cuttings or
buildings mask the railroad from the highway,--this distinction is
vital. In the one case notice of the unseen danger must be given
and cannot be unobserved; in the other case whether it is really
given or not may depend on the condition of the atmosphere or the
direction of the wind.
Usually, however, in New England the level crossings of the more
crowded thoroughfares, perhaps one in ten of the whole number, are
protected by gates or flag-men. Under similar circumstances in
Great Britain there is an electric connection between a bell in the
cabin of the gate-keeper and the nearest signal boxes of the block
system on each side of the crossing, so that due notice is given of
the approach of trains from either direction. In this country it has
heretofore been the custom to warn gate-keepers by the locomotive
whistle, to the intense annoyance of all persons dwelling near the
crossing, or to make them depend for notice on their own eyes. Under
the Hall system, however, the gate-keeper is automatically signalled
to be on the look out, if he is attending to his duty; or, if he is
neglecting it, the electric bell in some degree supplies his place,
without releasing the corporation from its liability. In America
the heavy fogs of England are almost unknown, and the brilliant
head lights, heavy bells and shrill high whistles in use on the
locomotives would at night, it might be supposed, give ample notice
to the most careless of an approaching train. Continually recurring
experience shows, however, that this is not the case. Under these
circumstances the electric bell at the crossing becomes not only a
matter of justice almost to the employé who is stationed there, but
a watchman over him.
This, however, like the other forms of signals which have been
referred to, is, in the electric system, a mere adjunct of its chief
use, which is the block,--they are all as it were things thrown
into the bargain. As contradistinguished from the English block,
which insures only an unoccupied track, the automatic blocks seek to
insure an unbroken track as well,--that is not only is each segment
into which a road is divided, protected as respects following trains
by, in the case of Hall's system, double signals watching over each
other, the one at safety, the other at danger,--both having to
combine to open the block,--but every switch or facing point, the
throwing of which may break the main track, is also protected. The
Union Signal Company's system it is claimed goes still further than
this and indicates any break in the track, though due to accidental
fracture or displacement of rails. Without attempting this the Hall
system has one other important feature in common with the English
block, and a very important feature, that of enabling station agents
in case of sudden emergency to control the train movement within
half a mile or more of their stations on either side. Within the
given distance they can stop trains either leaving or approaching.
The inability to do this has been the cause of some of the most
disastrous collisions on record, and notably those at Revere and at
Thorpe.
The one essential thing, however, in every perfect block system,
whether automatic or worked by operators, is that in case of
accident or derangement or doubt, the signal should rest at danger.
This the Hall system now fully provides for, and in case even of
the wilful displacement of a switch, an occurrence by no means
without precedent in railroad experience, the danger signal could
not but be displayed, even though the electric connection had been
tampered with. Accidents due to wilfullness, however, can hardly
be provided for except by police precautions. Train wrecking is
not to be taken into account as a danger incident to the ordinary
operation of a railroad. Carelessness or momentary inadvertence,
or, most dangerous of all, that recklessness--that unnecessary
assumption of risk somewhere or at some time, which is almost
inseparable from a long immunity from disaster--these are the
great sources of peril most carefully to be guarded against. The
complicated and unceasing train movement depends upon many thousand
employés, all of whom make mistakes or assume risks sometimes;--and
did they not do so they would be either more or less than men.
Being, however, neither angels nor machines, but ordinary mortals
whose services are bought for money at the average market rate of
wages, it would certainly seem no small point gained if an automatic
machine could be placed on guard over those whom it is the great
effort of railroad discipline to reduce to automatons. Could this
result be attained, the unintentional throwing of a lever or the
carelessness which leaves it thrown, would simply block the track
instead of leaving it broken. An example of this, and at the same
time a most forcible illustration of the possible cost of a small
economy in the application of a safeguard, was furnished in the
case of the Wollaston disaster. At the time of that disaster, the
Old Colony railroad had for several years been partially equipped
on the portion of its track near Boston, upon which the accident
occurred, with Hall's system. It had worked smoothly and easily, was
well understood by the employés, and the company was sufficiently
satisfied with it to have even then made arrangements for its
extension. Unfortunately, with a too careful eye to the expenditure
involved, the line had been but partially equipped; points where
little danger was apprehended had not been protected. Among these
was the "Foundry switch," so called, near Wollaston. Had this switch
been connected with the system and covered by a signal-target, the
mere act of throwing it would have automatically blocked the track,
and only when it was re-set would the track have been opened. The
switch was not connected, the train hands were recklessly careless,
and so a trifling economy cost in one unguarded moment some fifty
persons life and limb, and the corporation more than $300,000.
One objection to the automatic block is generally based upon the
delicacy and complicated character of the machinery on which its
action necessarily depends; and this objection is especially urged
against those other portions of the Hall system, covering draws
and level crossings, which have been particularly described. It
is argued that it is always liable to get out of order from a
great multiplicity of causes, some of which are very difficult to
guard against, and that it is sure to get out of order during any
electric disturbance; but it is during storms that accidents are
most likely to occur, and especially is this the case at highway
grade-crossings. It is comparatively easy to avoid accidents so long
as the skies are clear and the elements quiet; but it is exactly
when this is not the case and when it becomes necessary to use every
precaution, that electricity as a safeguard fails or runs mad, and,
by participating in the general confusion, proves itself worse
than nothing. Then it will be found that those in charge of trains
and tracks, who have been educated into a reliance upon it under
ordinary circumstances, will from force of habit, if nothing else,
go on relying upon it, and disaster will surely follow.
This line of reasoning is plausible, but none the less open to
one serious objection; it is sustained neither by statistics nor
by practical experience. Moreover it is not new, for, slightly
varied in phraseology, it has been persistently urged against the
introduction of every new railroad appliance, and, indeed, was first
and most persistently of all urged against the introduction of
railroads themselves. Pretty and ingenious in theory, practically it
is not feasible!--for more than half a century this formula has been
heard. That the automatic electric signal system is complicated,
and in many of its parts of most delicate construction, is
undeniable. So also is the locomotive. In point of fact the whole
railroad organization from beginning to end--from machine-shop to
train-movement--is at once so vast and complicated, so delicate
in that action which goes on with such velocity and power, that
it is small cause for wonder that in the beginning all plain,
sensible, practical men scouted it as the fanciful creation of
visionaries. They were wholly justified in so doing; and to-day
any sane man would of course pronounce the combined safety and
rapidity of ordinary railroad movement an utter impossibility, did
he not see it going on before his eyes. So it is with each new
appliance. It is ever suggested that at last the final result has
already been reached. It is but a few years, as will presently be
seen, since the Westinghouse brake encountered the old "pretty and
ingenious" formula. Going yet a step further, and taking the case
of electricity itself, the bold conception of operating an entire
line of single track road wholly as respects one half of its train
movement by telegraph, and without the use of any time table at
all, would once have been condemned as mad. Yet to-day half of the
vast freight movement of this continent is carried on in absolute
reliance on the telegraph. Nevertheless it is still not uncommon
to hear among the class of men who rise to the height of their
capacity in themselves being automaton superintendents that they do
not believe in deviating from their time tables and printed rules;
that, acting under them, the men know or ought to know exactly what
to do, and any interference by a train despatcher only relieves them
of responsibility, and is more likely to lead to accidents than if
they were left alone to grope their own way out.
Another and very similar argument frequently urged against the
electric, in common with all other block systems by the large class
who prefer to exercise their ingenuity in finding objections rather
than in overcoming difficulties, is that they breed dependence and
carelessness in employés;--that engine-drivers accustomed to rely
on the signals, rely on them implicitly, and get into habits of
recklessness which lead inevitably to accidents, for which they
then contend the signals, and not they themselves, are responsible.
This argument is, indeed, hardly less familiar than the "pretty and
ingenious" formula just referred to. It has, however, been met and
disposed of by Captain Tyler in his annual reports to the Board of
Trade in a way which can hardly be improved upon:--
It is a favorite argument with those who oppose the introduction
of some of these improvements, or who make excuses for the want
of them, that their servants are apt to become more careless
from the use of them, in consequence of the extra security which
they are believed to afford; and it is desirable to consider
seriously how much of truth there is in this assertion. * * *
Allowing to the utmost for these tendencies to confide too
much in additional means of safety, the risk is proved by
experience to be very much greater without them than with them;
and, in fact, the negligence and mistakes of servants are found
to occur most frequently, and generally with the most serious
results, not when the men are over-confident in their appliances
or apparatus, but when, in the absence of them, they are
habituated to risk in the conduct of the traffic. In the daily
practice of railway working station-masters, porters, signalmen,
engine-drivers or guards are frequently placed in difficulties
which they have to surmount as best they can. The more they are
accustomed to incur risk in order to perform their duties, the
less they think of it, and the more difficult it is to enforce
discipline and obedience to regulations. The personal risk which
is encountered by certain classes of railway servants is coming
to be more precisely ascertained. It is very considerable;
and it is difficult to prevent men who are in constant danger
themselves from doing things which may be a source of danger to
others, or to compel them to obey regulations for which they do
not see altogether the necessity, and which impede them in their
work. This difficulty increases with the want of necessary means
and appliances; and is diminished when, with proper means and
appliances, stricter discipline becomes possible, safer modes
of working become habitual, and a higher margin of safety is
constantly preserved.[14]
[14] Reports; 1872, page 23, and 1873, page 39.
In Great Britain the ingenious theory that superior appliances
or greater personal comfort in some indefinable way lead to
carelessness in employés was carried to such an extent that only
within the last few years has any protection against wind, rain and
sunshine been furnished on locomotives for the engine-drivers and
stokers. The old stage-coach driver faced the elements, and why
should not his successor on the locomotive do the same?--If made too
comfortable, he would become careless and go to sleep!--This was the
line of argument advanced, and the tortures to which the wretched
men were subjected in consequence of it led to their fortifying
nature by drink. They had to be regularly inspected and examined
before mounting the foot-board, to see that they were sober. It took
years in Great Britain for intelligent railroad managers to learn
that the more protected and comfortable a man is the better he will
attend to his duty. And even when the old argument, refuted by long
experience, was at last abandoned as respected the locomotive cab,
it, with perfect freshness and confidence in its own novelty and
force, promptly showed its brutal visage in opposition to the next
new safeguard.
For the reasons which Captain Tyler has so forcibly put in the
extracts which have just been quoted, the argument against the block
system from the increased carelessness of employés, supposed to be
induced by it, is entitled to no weight. Neither is the argument
from the delicacy and complication of the automatic, electric signal
system entitled to any more, when urged against that. Not only has
it been too often refuted under similar conditions by practical
results, but in this case it is based on certain assumptions of
fact which are wholly opposed to experience. The record does not
show that there is any peculiar liability to railroad accidents
during periods of storm; perhaps because those in charge of train
movements or persons crossing tracks are under such circumstances
more especially on the look out for danger. On the contrary the
full average of accidents of the worst description appear to
have occurred under the most ordinary conditions of weather, and
usually in the most unanticipated way. This is peculiarly true of
accidents at highway grade crossings. These commonly occur when the
conditions are such as to cause the highway travelers to suppose
that, if any danger existed, they could not but be aware of it.
In the next place, the question in regard to automatic electric
signals is exactly what it was in regard to the Westinghouse brake,
with its air-pump, its valves and connecting tubes;--it is the
purely practical question,--Does the thing work?--The burden of
proof is properly on the inventor. The presumption is all against
him. In the case of the electric signals they have for years been
in limited but constant use, and while thus in use they have been
undergoing steady improvement. Though now brought to a considerable
degree of comparative perfection they are, of course, still in
their earlier stage of development. In use, however, they have not
been found open to the practical objections urged against them. At
first much too complicated and expensive, requiring more machinery
than could by any reasonable exertions be kept in order and more
care than they were worth, they have now been simplified until a
single battery properly located can do all the necessary work for
a road of indefinite length. As a system they are effective and do
not lead to accidents; nor are they any more subject than telegraph
wires to derangement from atmospheric causes. When any disturbance
does take place, until it can be overcome it amounts simply to a
general signal for operating the road with extreme caution. But with
railroads, as everywhere else in life, it is the normal condition of
affairs for which provision must be made, while the dangers incident
to exceptional circumstances must be met by exceptional precautions.
As long as things are in their normal state, that is, probably,
during nineteen days out of twenty, the electric signals have now
through several years of constant trial proved themselves a reliable
safeguard. It can hardly admit of doubt that in the near future they
will be both further perfected and generally adopted.