IMPROVE- MENTS IN THE MEANS OF AND APPARATUS FOR SIGNALLING ON RAILWAYS
Year: 1868

page_text: LETTERS PATENT to John Alexander, of Westport, Ireland, and
James Hill, of the City of Dublin, for the Invention of "IMPROVE-
MENTS IN THE MEANS OF AND APPARATUS FOR SIGNALLING ON RAILWAYS,"
PROVISIONAL SPECIFICATION left by the said John Alexander and
James Hill at the Office of the Commissiouers of Patents, with
their Petition, on the 2nd December 1868.
We, JOHN ALEXANDER, of Westport, Ireland, and JAMES HILL, of
the City of Dublin, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN THE MEANS OF AND APPARATUS POR SIGNALLING ON
RAILWAYS," to be as follows:-
This Invention relates to certain improvements in the means of
actuating signals on railways, and in the apparatus to be employed
therein, the object being to effect a self-acting system and to dispense
with personal attendance and with signals worked by electricity.
In order to accomplish these results the passage of the locomotive over
particular portions of the line is made the motive power for working
[Price]

page_text: the signals, either at the extremities of sharp curves, the entrances to
tuunels or stations, or even along the entire line of railway if required.
We propose to arrange on either side of the rail, or of both rails, a
bar of iron or steel presenting a raised curvilinear or segmental surface
above the level of the rail, such raised surface receiving contact from
the flange or edge of the tyre of the wheels of the engine or train and
becoming thereby depressed to the level of the rails; the rails them-
selves will not therefore be interfered with, and the engine guard bars
will be free to travel over the rails without touching the raised segmental
bur. This bar should be from six to eight feel or thereabouts in length,
and a corresponding depth, on the principle of a boam or girder to
resist a lever strain, and is attached at one end to a fulcrum or axis
below-the-level of the rails and at right angles thereto. The ends of
the bar are formed with a gradual ascent, each extremity lying well
below the surface of the rail to permit the engine wheels to run smoothly
thereon, and to effect a gradual depression from the fulcrum or axis,
which then extends completely in a transverse direction under the rails
to any extent required, to act on a vertical arm to which is attached the
chain or rope by which the signals- are. operated; or the vertical arın
may be attached to the rocking segmental bar at the side thereof clear
of the train, to actuate a signal at that point, the chain or rope is then.
carried along the line on rollers set on vertical standards in the ordinary
manner to the next signal post, when further attachments are made to the
signal levers at such point, and so on, as may be thought necessary. The
curvilinear bar to be depressed should be constructed with its bearings and
attachments in connection with a length of rail, and the whole applied at
once wherever necessary, in place of the ordinary rail. The method of
construction will be easily understood by any one conversant with railway
work.
Now the operation of these arrangements is as follows:-When the
engine arrives at any one signalling bar the wheel or wheels depress
the same, and the leverage power being communicated to the rope or
chain, the signal to which it immediately appertains becomes elevated,
thus denoting danger to a following train; and the strain on the con-
tinuation of the rope or chain to the next signalling post in advance
causes simultaneously the elevation of that signal denoting the approach
of the train, which passing in its course such advanced signal it becomes
again depressed as well as the one it previously elevated, and again
elevates the next signal in advance. The rope or chain should be made

page_text: of sufficient lightness to reduce the friction to a minimum, and yet of
ample strength to endure the strain upon it, but counterweights and
springs may be applied to the different signal levers to render as far as
possible an equilibrium of strain, and thus reduce the power necessary
to work them, whether they consist of disc signals turning on a
horizontal centre or pivot, or the more frequent arm signals where
greater power is required. Revolving lights may be easily operated, or
their shades or covers applied and removed. So also a bell may be rung
at a distant station to denote the approach of the train. There may be
a hand lever with its attachments applied to the rope or chain at any
convenient situation between two signal posts, or at either, to reverse
the signals in exceptional cases; and in order to ensure the greater
safety of trains at stations the second signal post should be at a short
distance beyond the station because while the train is waiting, and not
having passed the second signal, no other train will follow until such
second signal shall have been passed by the final departure of the train;
and all other trains shunting at the sidings or preparing to start, and
which have not passed over the first signal, should while making ready,
if possible, not enter on the main line or principal rails inside the
second signal, but when ready, instead of passing over the second, pass
in on the main line beyond it which will ensure their own safety and
that of the trains which pass in regular course over the first, and into
the station, unless the danger signal has been raised as before stated,
by the hand lever. So also, at junctions where several lines of rails
throw their trains in on the trunk line the first section of such line
would be the best position for the first and second signal posts, whereby
the safety of the respective trains would be ensured. In order to
compensate for the expansion and contraction of the wires, chains, or
ropes whereby the signalling apparatus described are respectively con-
nected we propose to form junctions in such wires, chains, or ropes at
intervals between some or all the supporting pillars, and to apply to
such junction helically coiled steel springs fixed within the ends of the
wire, chain, or rope by means of hooks or other equivalent means, the
effect of which will be that an uniform degree of tension will be given
to the entire system, because when from the changes of temperature or
other cause, the sections of the rope, wire, or chains expand or contract,
the springs will respectively exercise a contrary influence and allow of
such contraction or expansion while constantly and invariably maintain-
ing a tension sufficient to ensure the motion of the depressing segmental

page_text: or curvilinear bar effecting the exact degree of movement required for the
signals. This improvement is of course applicable to all other systems of
signalling where such ropes, wires, or chains are employed. Moreover, it
permits of the adjustment or removal of the connecting medium, in a very
convenient manner, without the necessity of drawing long lengths of wire,
chain, or rope through a number or series of pillars and lessens the labour
and expense. The hooks could be formed with sockets attached, a screw
thread being cut therein, whereby a few turns of the hook and socket on
the ends of the wire rope which is commonly used would make a firm and
lasting connecting link for the spring. By these arrangements it will
be obvious that with the exception of working the hand levers (of which
few would-be-required in practice) this system in self-acting, and thereby
rendered more safe than in those cases where electrical communication-is-
used between every station to regulate the traffic. It is obvious that
the actions of the signals may be varied beyond the extent herein
described, it being only necessary here to point out the principles whereon
the Invention is based, from which all other modifications of arrangement
may be deduced.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Alexander and James Hill in the Great Seal
Patent Office on the 2nd June 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, JOHN
ALEXANDER, of Westport, Ireland, and JAMES HILL, of the City of Dublin,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Second day of December, in the
year of our Lord One thousand eight hundred and sixty-eight, in the
thirty-second year of Her reign, did, for Herself, Her heirs and
successors, give and grant unto us, the said John Alexander and
James Hill, Her special licence that we, the said John Alexander
and James Hill, our executors, administrators, and assigns, or such
others as we, the said John Alexander and James Hill, our executors,
administrators, and assigns, should at any time agree with, and no
others, from time to time and at all times thereafter during the terin

page_text: therein expressed, should and lawfully might make, use, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN
THE MEANS OF AND APPARATUS FOR SIGNALLING ON RAILWAYS," upon the
condition (amongst others) that we, the said John Alexander and
James Hill, our executors or administrators, by an instrument in
writing under our, or their, or one of their hands and scals, should
particularly describe and ascertain the nature of the said Invention,
and in what manner the same was to be performed, and cause the
same to be filed in the Great Seal Patent Office within six calendar
months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that we, the said John Alexander and James Hill.
do hereby declare the nature of our said Invention, and in what manner
the same is to be performed, to be particularly described and ascertained
in and by the following statement :-
This Invention relates to certain improvements in the means of
actuating signals on railways, and in the apparatus to be employed therein,
the object being to effect a self-acting system and to dispense with
personal attendance and with signals worked by electricity. In order
to accomplish these results the passage of the locomotive over particular
portions of the line is made the motive power for working the signals,
either at the extremities of sharp curves, entrances to tunnels or
stations, or even along the entire line of railway if required. We
arrange on either side of the rail, or of both rails, a bar of iron
or steel presenting a raised curvilinear or segmental surface above the
level of the rail, such raised surface receiving contact from the flange or
edge of the tire of the wheel of the engine or train, and becoming
thereby depressed to the level of the rails; the rails themselves will not
therefore be interfered with, and the engine guard bars will be free to
travel over the rails without touching the raised segmental bar. This
bar should be from six to eight feet, or thereabouts, in length, and a
corresponding depth, on the principle of a beam or girder to resist a lever
strain, and is attached at or near one end to a fulcrum or axis below the
level of the rails and at right angles thereto; the ends of the bar are
formed with a gradual ascent, each extremity lying well below the
surface of the rail to permit the engine wheels to run smoothly thereon,
and to effect a gradual depression from the fulcrum or axis, which then

page_text: extends completely in a transverse direction under the rails to any extent
required, to act on a vertical arm to which is attached the chain or rope
by which the signals are operated, and where required to work along the
eutire line; what is technically called a "dog" is made to work into each
lever, so as to cause a continuation or succession of signals to operate so
as to effect only those as required as the train passes on. Or the vertical
arm may be attached to the rocking segmental bar at the side thereof
clear of the train to actuate a signal at that point; the chain or rope is
then carried along the line on rollers set on vertical standards in the
ordinary manner to the next signal post, when further attachments are
or may be made to the signal levers at such point, and so on, as may
be thought necessary. The curvilinear bar to be depressed should be
constructed with its bearings and attachments in connection with a
length of rail, and the whole applied at once wherever necessary
in place
of the ordinary rail.
The method of construction will be easily understood by any one con-
versant with railway-work.
Now the operation of these arrangements is as follows:-When the
engine arrives at any one signalling bar, the wheel or wheels depress
the same, and the leverage power being communicated to the rope or
chain, the signal to which it immediately appertains becomes elevated,
thus denoting danger to a following train; and the strain on the con-
tinuation of the rope or chain to the next signalling post in advance
causes simultaneously the elevation of that signal, denoting the approach
of the train, which passing in its course such advanced signal it becomes
again depressed, as well as the one it previously elevated, and again
elevates the next signal in advance. The rope or chain should be made
of sufficient lightness to reduce the friction to a minimum, and yet of
ample strength to endure the strain upon it, but counterweights and
springs may be applied to the different signal levers to render as far
as possible an equilibrium of strain and thus reduce the power necessary
to work them, whether they consist of disc signals turning on
horizontal centre or pivot, or the more frequent arm signals where
greater power is required. Revolving lights may be easily operated, or
their shades or covers applied and removed. So also a bell may be rung
at a distant station to denote the approach of the train.
There may be
a hand lever with its attachments applied to the rope or chain at any
convenient situation between two signal posts, or at either, to reverse
a

page_text: the signals in exceptional cases; and in order to ensure the greater safety
of trains at stations the second signal post should be at a short distance
beyond the station, because while the train is waiting, and not having
passed the second signal, no other train will follow until such second
sigual shall have been passed by the final departure of the train, and all
other trains shunting at the sidings, or preparing to start, aud which have
not passed over the first signal, should, while making ready, if possible,
not enter on the main line or principal rails inside the second signal, but
when ready instead of passing over the second pass in on the main line
beyond it, which will ensure their own safety and that of the trains which
pass in regular course over the first and into the station unless the danger
signal has been raised, as before stated, by the hand lover. So also at
junctions where several lines of rails throw their traius in on the trunk
line, the first section of such line would be the best position for the first
and second signal posts, whereby the safety of the respective trains would
be ensured.
In order to compensate for the expansion and contraction of the wires,
chains, or ropes whereby the signalling apparatus described are respectively
connected, we form junctions in such wires, chains, or ropes at intervals
between some or all the supporting pillars, and apply to such junction
helically coiled steel springs fixed within the ends of the wire, chain, or
rope by means of hooks or other equivalent means, the effect of which will
be that an uniform degree of tension will be given to the entire
system, because when from the changes of temperature or other cause
the sections of the rope, wire, or chains expand or contract, the
springs will respectively exercise a contrary influence and allow of such
contraction or expansion while constantly and invariably maintaining a
tension sufficient to ensure the motion of the depressing apparatus or
curvilinear bar effecting the exact degree of movement required for the
signals.
This improvement is of course applicable to all other systems of
signalling where such ropes, wires, or chains are employed. Moreover,
it permits of the adjustment or removal of the connecting medium in a
very convenient manner, without the necessity of drawing long lengths of
wire, chain, or rope through a number or series of pillars, and lessens the
labour and expense. The hooks could be formed with sockets attached,
a screw thread being cut therein, whereby a few turns of the hook and

page_text: locket on the ends of the wire rope which is commonly used would make
a firm and lasting connecting link for the spring.
In order that our Invention may be more completely understood, we annex
the accompanying Drawings in which Fig. 1 represents a side view of the
apparatus, whereby the signals are actuated by the passage of the loco-
motive over the rails; Fig. 2 being a plan view shewing the position of the
segmental bar in relation to the rail, the outer sides of the flanges being
cut away toperm it the bar to come under the tyre of the wheels and be
thereby depressed The various arrangements of signals are not shewu as
no novelty is sought to be claimed in regard to them, and therefore it is uoi
necessary to detail any special arrangement of signal posts, levers, pulleys,
-or-signals, but merely the method by which such devices may be primarily
actuated.
In Fig. 1, a represents the outer rail, the train being supposed to
travel in the direction of the arrow; b shews the segmental depressing
lever bar set on a fulcrum c below the rail, the form of curve ou which
the wheels of the locomotive and train are to bear is shewn by the
line b' presenting a gradual ascending slope terminating at the apex 62;
and passing below the rail again by the incline 63, so that when the
wheels have arrived at the apex the bar is depressed to its extreme
limit; the highest level of the bar above the rail may be two, three,
four, or six inches according to the depression required, and the extent
of motion required to be given to the connecting medium of the signals,
but this will depend upon the length of the bar and the position of the
fulcrum which may be made to shift in a bearing so as to alter its
elevation; the front of the bar is formed with a descending beak or head
to the extremity of which an arm is bolted by flanges at a right angle
to the line of the bar, such arm extending a sufficient distance to actuate
a balanced detent or curvilinear tooth d to which the vertical staudard e
is attached, being the point of suspension of this arrangement, the
standard being well clear of the train. It will be observed that there is
no attachment between the bar and balanced tooth, but that the action
of the tooth is simply dependent on the depressing contact of the bar,
when actuated by the passage of the train or locomotive, and by this
simple construction a great principle is effected which has often been
attempted, viz., the disconnection or independence of each signalling
apparatus. The apertures g, y, formed in the bar and tooth are for the
purpose of attaching balance weights in order to maintain as near as

page_text: possible an equilibrium so as to require the smallest amount of power to
work them, and also that they may be restored to their normal position
by gravity alone. In the Drawing two series of apparatus are shown.
the distance between the two being dependent on the nature of the line
of railway, whether at a sharp curve or a junction, or the entrance of
a tunnel, or near the approach of a station, and in such cases the
balanced catches may be dispensed with and the bars only used to
actuate the signals, one bar being connected to the other by wires or
chains passing over suitable pullies and guide posts. On the assumption
that only two of the apparatus are placed at some point where it is
necessary to prevent the too close following of one train to another, the
first train would depress the bar b and bring down the tooth, thereby
tilting forward the standard or pillar e as shewn by the dotted lines to
which one or more wires, chains, or ropes are to be attached extending to
a suitable distance down the line to actuate a signal of danger to the
following train. To the head of the bar (say at the part h,) a similar wire,
chain, or rope should be attached by means of a horizontal rod, such
wire, chain, or rope continuing on suitable supports to the next
apparatus in advance and connected to the standard as before, the wire
being actuated by the depression of the tooth, but when the engine and
train reach the second apparatus and depress the bar b, the standard e
will be brought over and thereby pull up the bar of the first, releasing
the tooth, and permitting the standard to assume the vertical, thus
slackening the connection between the first standard and the extreme
rear signal, which then will be in a position to indicate safety to the
approaching train. The second apparatus in such example. may be so
weighted as to return to its first position when the train passes over the
first lever, and the second one will not go up till the next train has
arrived at the first, but in case of a continuous line of apparatus being
required it is evident that they may be arranged at suitable distances in
any number required according to the exigencies of the railway. Since
it will be necessary wherever the apparatus is applied to the rail to leave
a sufficient space for its free operation, the rail may be supported by a
longitudinal girder on a foundation or flange on the principle of I iron,
on which the bearings may be made, or by short uprights or blocks upon
which the other sleepers may rest, or if necessary a framework, case, or
box of iron may be made to contain and support the whole, and in some
instances the entire apparatus containing also a length of rail may be
made complete and applied in substitution of an ordinary rail and

page_text: sleepers at any situation required. In the Drawing Fig. 1, the train is
supposed to have passed over the first lever and depressed it, raising the
sigual to danger, where it will remain until released by the passage of
the train over the other lever, when it will be again lowered to safety by
the ascent of the lever and the depression of the second, here the attach
ments are also shewn between the levers and signals and are made direct
without the aid of the standards.
Having now described the nature of our said Invention and the manner
in which the same is to be performed, we would remark that we do not
restrict ourselves to the exact details and configuration of apparatus we
Lave described and shewn, as the same may be modified or varied as
experience may suggest, but what we claim and desire to be secured to us
by the herein in part recited Letters-Patent-are,-
Firstly. The means and apparatus whereby primary motion is given to
signals on railways by the passage of a locomotive or train over the rail to
which such apparatus is applied, and which consists of the depressing
lever in connection or not with the catches and standards as required,
acting-in-unison with a second depressing lever, and with wires, chains, or
ropes, and signals.
And, secondly. The means of effecting the junctions of the lengths..of
wire, chain, or rope in order to counteract the results of expansion and
contraction, both substantially as herein specified.
In witness whereof, we, the said John Alexander and James Hill,
have hereunto set our hands and seals, this First day of June,
in the year of our Lord One thousand eight hundred and sixty-
nine.
Witness,
ALEX. PRINCE,
Office for Patents,
4, Trafalgar Square,
Charing Cross.
JOHN ALEXANDER. (L.S.)
JAMES HILL.
(L.S.)