Improvements in or relating to Railway or similar Signalling.
Year: 1895

page_text: Date of Application, 2nd May, 1895
Complete Specification Left, 3rd Feb., 1896-Accepted, 21st Mar., 1896
PROVISIONAL SPECIFICATION.
Improvements in or relating to Railway or similar Signalling.
We, WILFRID SWANWICK BOULT of 60 Castle Street, Liverpool, in the
County of Lancaster, Electrical Engineer, and CEDRIC RANDAL BOULT of
62 Dale Street, Liverpool aforesaid, Merchant, do hereby declare the nature of
this invention to be as follows:-
The subject of this invention is a development of the system described in our
previously filed Specifications, namely, No. 17041 of 1893, and No. 11773 of 1894,
and has reference to methods of continuously giving a desired signal on a moving
train, by means of the magnetism developed by maintained electric currents,
whether, "continuous" alternating, or pulsating, in conductors laid along the track.
When using continuous currents (and as having no possible ill effects on
telephone or telegraph circuits they are to be preferred to alternating currents),
for non-automatic working, the method we prefer is as follows;-Between every
two successive block-stations, we lay two parallel insulated conductors either of
which can at the will of the signalman be utilised for conveying the electric current
while the other is idle. In order to enhance the magnetic effect of the current we
may lay the conductors each in an iron trough, preferably in the middle and about
at the level of its edges.
"
Each conductor with or without a trough thus forms a continuous electro-magnet
along the line, and over each such electro-magnet the train will carry (with or
without a "divided armature") a "contact-maker " or equivalent such as is
described in our above named previous Specifications the contact-maker in each
case being arranged to give one signal only or not to give it according as the track
magnet below is energised or not. One contact-maker may give the
66 danger
signal and the other the "line clear" and thus as long as current is maintained in
the conductors on the road-bed, and in the local circuits on the train if any, a
positive signal is given on the train. Should the current in any circuit fail the
fact is at once indicated to the driver by his signal falling to a third position which
it never occupies when all is working properly. Instead of two separate continuous
electro-magnets as described we may use one only with reversible current.
By this arrangement of track conductors, although ordinarily a signalman would
only interfere with the section before his cabin, a switch could be arranged by
which he could on an emergency cut the current off from the following section
(sending it by a third conductor to the section after that) and so caution the driver
of a train that had passed him.
For automatic block signalling the switching of the track current may be effected
by a magnet on the train.
Instead of a comparatively large current being taken once along each track a
correspondingly smaller current may be taken oftener.
If alternating or pulsating currents are to be used the arrangement of track
conductors and troughs may he as above described, two separate ones being in this
case necessary but the receiving apparatus on the train may consist of an inverted
trough or equivalent wound with one or more turns of insulated wire in which
secondary currents will be generated, which secondary currents may be utilised in
suitable apparatus, either with or without a relay. In all cases the troughs
any

page_text: may be formed with lips so as to afford a large polar surface for the induced
magnetism at the "air-gap."
Dhi and 100
BOULT & WADE,
Agents for the Applicants.
Improvements in or relating to Railway or similar Signalling.
We, WILFRID SWANWICK BOULT, formerly of 60 Castle Street Liverpool in
the County of Lancaster, but now of 14 South Parade, Chelsea, in the County of
London, Electrical Engineer, and CEDRIC RANDAL BOULT, of 62 Dale Street,
Liverpool, in the County of Lancaster, Merchant, do hereby declare the nature of
this invention, and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
The subject of this invention is a development of the system described in the
Specifications of prior Letters Patent granted to us, namely No. 17041 of 1893,
No. 11773 of 1894 and No. 2282 of 1895, and has reference to methods of
continuously giving a desired signal on a moving train by means of magnetism
developed by maintained electric currents, whether continuous, alternating, or
pulsating, in conductors laid along the track.
When using continuous or any uni-directional current, even if it be rapidly
intermitted or made to pulsate, we may employ the following arrangement,
namely Between every two successive block-signalling stations we lay two
parallel insulated conductors either of which can at the will of the signalman be
utilized for conveying the electric current while the other is "idle." In order to
enhance the magnetic effect of the current we may lay the conductors each in an
iron trough, preferably in the middle of the trough and about at the level of its
edges. Or as equivalent to the trough we may use a series of iron bars or plates
connected together or not, and partially surrounding the conductors.
91
61
Each conductor, with or without a trough, thus constitutes a continuous electro-
magnet along the line, and over each such electro-magnet the train will carry a
"contact-per or equivalent (with or without a "divided armature") such an is
de cried in our Love Sipcifications of prior Letters Patent, the contact-
maker or equivalent device in each case being arranged to give one signal only or
not to give it according as it is passing along an energised or non-energised trough
or conductor. One conductor and contact-maker may co-operate to give the
"danger
signal and the other conductor and a contact-mer the line-clear"
signal and thun, as long as current is maintained in either conductor along the track
and in the corresponding local circuits on the train a positive signal is given on the
train. Should the current in any of these circuits fail, the fact will be at once
indicated to the driver by his signal, which should be arranged to fall, under such
conditions, to a third position. Instead of two separate continuous electro-magnets
as described, we may use only one with reversible current and a polarised contact-
maker of such a kind, for example, as is described in our aforesaid prior Specification
of Letters Patent No. 11773 of 1894; in this case alternating current would not
be suitable, but rapidly-intermitting or pulsating uni-directional current would
serve.
By these arrangements of truck-conductors, although ordinarily a signalman
would only interfere with the section before his cabin, a switch can be arranged by
which he can un en emergency cut the current off from the signalling section into
which a train has just entered sending it by a third conductor hereinafter termed
**by-pass to the section into which the train would next enter, so cautioning
the driver of a train that had pa-ed the signahan's cabin, the cautionary a

page_text: being conveniently given by the assumption of a neutral position by the indicating-
device, i.e., the "third" position previously referred to.
For automatic block-signalling, the switching of the track-current instead of
being effected manually may be effected in the manner described in the Specification
of our prior Letters Patent No. 2282 of 1895.
Instead of a comparatively large current being taken by a single conductor as
hereinbefore described once along the track a proportionately smaller current may
be taken along the track in each of several related conductors or through several
turns of a single conductor.
If alternating currents are to be used, the arrangement of track-conductors and
troughs may be as above described, two separate troughs and conductors (as in
Fig. 1 for instance) being in this case necessary, but the receiving apparatus on
the train may consist of an inverted trough or equivalent (such as the T-ended
armature described in the aforesaid Specification No. 11773 of 1894 without a gap
for a contact-maker) wound with one or more turns of insulated conductor in
which secondary currents will be generated by the primary or track current which
secondary currents may be utilised in any suitable apparatus, either with or without
the aid of a relay. In all cases the troughs may be forned with lips so as to
afford a large polar surface for the induced magnetism at the air-gap.'
In the accompanying drawings
66
"
Figure 1 is a diagrammatic plan showing an arrangement with two troughs each
with one insulated conductor therein, and suited for direct, alternating or pulsating
current.
Figure 2 is a similar plan showing an arrangement with a single trough and two
oppositely-flowing currents.
Figure 3 is a section through one trough of Figure 1 showing the train-armature
in the position which it would occupy above it.
Figure 4 is a similar section showing a train-armature for alternating current.
Figure 5 is a section of the trough in Figure 2, showing it turned up sideways
and carried on vertical posts, the train-armature being also carried sideways as
shown.
Figures 6 and 7 are diagrammatic plans similar to Fig. 1 of alternative
arrangements hereinafter explained.
In all the figures like parts are indicated by the same letters.
A B and C are three signal-cabins, controlling signal-sections of the railway,
which sections will be respectively referred to as sections A, A B, and B C
(section A being the section extending from the bottom of the sheet to the cabin A
on the accompanying drawings, section A B being that between cabins A and B,
and section B C that between cabins B and C).
The current in these sections is controlled by switches composed each of two
arms a' and a 2 or 1 and 2 or c' and c 2 each arm of each pair being pivotted so as
to be able to turn independently of its companion arm about the pivot a or b or c
as the case may be. These switches would be placed in the several cabins, but are
shown outside for clearness; the small circles on the conductors indicate contact
terminals. T are iron troughs with lips t, and D are insulated conductors for
magnetising the troughs T. E are the "bye-pass conductors for allowing the
troughs of any section such as B C, for instance to be thrown out of action without
cutting the current off from other sections before and behind it.
"
F Figs. 3 and 5 are train armatures with longitudinal pole-plates or T-ends f
such as are illustrated in Fig. 4 of the drawings appended to the aforesaid
Specification of prior Letters Patent No. 11773 of 1894 and contact-makers or
elays indicated by the needle G; these are intended for use with continuous-
current track circuits, or other uni-directional current circuits.
H, Fig. 4 is an undivided armature with similar pole-plates and a coil J for
use with alternating or equivalent fluctuating current-.
K, Fig. 5 is a post for supporting a trough and conductors alongside the track.

page_text: The direction of traffic is shown by the large arrows, and the course of the
electric currents by small arrows.
In the arrangements illustrated in Figs. 1 and 2 any suitable source of electric
energy may be employed; the connections between this source and the conductors D
are not shown in the drawings, but it will be readily understood that they may be
permanent connections such as will cause current to flow say upward in Fig. 1 by
way of either conductor D, or, in Fig. 2 to flow downward by way of the upper
end of either of the conductors of the right-hand pair, and upward by way of the
lower end of either of the conductors of the left-hand pair.
Consider first the arrangement shown in Figs. 1, 3 and 4. Tracing the course
of the current by means of the small arrows and the switches a' a² 52 c¹ c² it will
be seen that, in section A, only the left hand trough T is energised; in section A B,
only the right-hand trough; and in section BC the current is switched clear of
the troughs altogether by way of the bye-pass E. Thus section A may be giving
the "line clear" signal to an advancing train, through signalling devices carried
by the train along the left hand trough, while section. A B is blocked by the
operation of the current in the right-hand trough to protect another train which
has entered section BC, in which signalman Chad given "line clear." As this
last mentioned train passed cabin B, the signalman is supposed to have noticed
something wrong with it and to have immediately warned the driver by diverting
his signalling current from that section entirely, thus causing the driver to receive
a caution signal by the assumption of a neutral position (the "third position
bereinbefore referred to) on the part of the driver's signal for instance, or by the
release of any suitable signal on the engine which normally is held up by whichever
of the ordinary signalling currents happens to be flowing. Or the current diverted
through the bye-pass may be utilised to give a positive signal; for instance the
bye-pass conductor may be put in a trough and operate a special alarm signal on
the engine, in a manner similar to that in which the conductors D operate. It
may also be utilized to inform the signalman in the succeeding section that the
bye-pass is being made use of.
"
The use of two troughs as described with reference to Figs. 1, 3 and 4 involves
the use also of two train-armatures each to give one signal only. An arrangement
whereby one armature with such a polarised contact-maker for instance as is
hereinbefore referred to may give the two different signals is shown in Figs. 2
and 5. In this case there is only one trough T, but instead of being as in the
previous example simply magnetised or nut magneti-ed the direction of the
magganisation is capable of reversal. For this purpurealapter 1)
are shown which can be used in pairs-one comictor of each pair being locatel
inside the trough and the other outside; current flowing in two directions is also
required, and is indicatel by the small arrows.
In tion A (Fig. 2) the left-hand or up" current is out-ile the trough anl
the "down" current inside, thus making the left-hand lip into a S pole and the
right-hand lip into a N pole; in retion AB, these conditions are reversed; and,
in section BC, the trough is not magnetised. The bye-passes E are similar to
those described for Fig. 1 but are in duplicate.
With the arrangement shown in Fig. 1, continuous, alternating or pulsating
current may be used, but for Fig. 2 only continuous or other uni-directional
current is suitable.
In both Fig. 1 and Fig. 2 the troughing is shown as extending over the full
length of each section, but in long sections it might be laid for a part of the
distance only-say from the place of the usual home signal hack to a little before
the place at which the distant signal would ually be situated and in either case
might be divided so as to indicate to the driver how far he had travelled. Thus
suppe the troughing for a section to he say 1200 yards in length, it might be
divided by a pap into two portions the first say NC yards long run
the

page_text: Instead of having the distant and home troughs in a continuous line, they may
be so placed as to face separate armatures on the train and thus give distinctive
signals.
For instance the engine might carry on each side an armature mounted as F
Fig. 5, the distant trough facing one and the home-trough the other. To allow of
the engine running either end first, the connections of the signal instruments and
local circuits could be suitably altered by a switch or each instrument might
actuate two signals; the signal not required for the time being could be covered
by a sliding screen.
In the modification illustrated in Fig. 6 only one signal section is included in
a circuit DL from a source of electricity M-for instance a primary or secondary
battery in or near each controlling signal-cabin, a trough T with reversible
magnetisation will require only two conductors D instead of the six conductors D
and E shown in Fig. 2; one of these conductors being inside the trough and the
other outside and the current being reversible in these two conductors and controlled
by a reversing switch d of well-known construction in the cabin. To give the
"caution" signal to a train in any such section it is only necessary that the circuit
shall be interrupted anywhere say at X for instance; other sections not being
interfered with thereby.
In the modification illustrated in Fig. 7 the sections are in series on the same
electric circuit E' and even then the number of conductors may be reduced to
four, viz. ; two trough conductors D D with reversing-switch d as just described
and a bye-pass conductor E under the control of the signalman at the "preceding"
cabin by the switch e, to switch current past a section in the manner hereinbefore
described. The other conductor E' connects the switches of successive sections
together in series as shown.
Other modifications of the arrangements of parts both on the track and on the
train may be effected without departing from the spirit of this invention.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed we declare that what we
claim is ;-
1. Railway or similar signalling apparatus operating by continuous utilisation
of a maintained electro-magnetic field substantially as described.
2. In railway or similar signalling the combination of a pair of electrical
conductors such as D adapted to produce long electro-magnetic "fields" lying in
the direction of movement of the traffic and switches to cause one of such
conductors at a time to become energised substantially as and for the purpose
described.
3. In railway or similar signalling a single electrical conductor D of uni-
directional or alternating current arranged to produce an approximately constant
magnetic field utilized directly to actuate signalling-apparatus substantially as
described.
4. In railway or similar signalling the combination of a single electrical
conductor such as D arranged to produce an approximately constant magnetic
field utilized directly to actuate signalling-apparatus and automatic or other means
to effect reversal of an uni-directional flow of current in that conductor for the
purposes described.
5. In railway or similar signalling the combination with a source of electric
energy of a device such as the two conductors D or two sets of electrical
conductors D and switches with or without a trough T producing an electro-
magnetic field of reversible polarity the whole operating substantially as and for
the purpose described.
6. In railway or similar signalling a bye-pass circuit such as E employed to give
a positive signal substantially as described."
7. In railway or similar signalling the combination with apparatus such as
described in sets appropriated to successive signalling-sections of the railway of

page_text: bye-pass circuits such as E and switches to divert the current out of a section
through a bye-pass circuit substantially as and for the purpose described.
8. In railway or similar signalling a trough-shaped electro magnet with lips or
flanges such as t.
9. In railway or similar signalling the combination with a conductor such as D
of a trough such as T with or without flanges such as t for the purpose described.
10. In railway or similar signalling a trough electro-magnet such as is herein-
before described with the exciting conductor D in or near the middle of the trough
opening and about in the plane of its edges or lips.
11. In railway or similar signalling apparatus of the kind hereinbefore described
with reference to the employment of alternating electric currents a train armature
such as H with or without lips h and with a winding such as J substantially as
and for the purpose described.
12. In railway or similar signalling apparatus the combination with a conductor
such as D with or without a trough such as T of an armature such as H with a
winding such as J substantially as and for the purpose described.
13. The combination and arrangement of signalling apparatus substantially as
and for the purposes described and illustrated in Figure or Figure 2 or Figure 4
or Figure 5 or Figure 6 or Figure 7 of the accompanying drawings.
Dated this 3rd day of February 1896.
Witness to the signature of C. R. Boult―
K. F. BOULT,
Brooke House,
Blundellsands.
W. S. BOULT.
C. R. BOULT.
Boult & Wade,
Agents for the Applicants.