IMPROVEMENTS IN SIGNALLING ON RAILWAYS, INCLUDING APPLIANCES USED THERE- FOB
Year: 1875

page_text: LETTERS PATENT to Samuel Telford Dutton, of Worcester, in the
County of Worcester, for the Invention of "IMPROVEMENTS
"
IN
Sealed the 11th May 1875, and dated the 13th March 1875.
PROVISIONAL SPECIFICATION left by the said Samuel Telford Dutton
at the Office of tho Commissioners of Patents, with his Petition, on
the 13th March 1875.
I, SAMUEL TELFORD DUTTON, of Worcester, in the County of
Worcester, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN SIGNALLING ON RAILWAYS, INCLUDING APPLIANCES USED THERE-
FOB," to be as follows:-
:-
This Invention refers chiefly to arrangements for giving a distin-
guishing or a series of distinguishing signals from the lamps in the form
of numbers, letters, or words, and also in the mode of working signals
conjointly acted upon by different signalmen, also indicating distant
signals.

page_text: The mode of carrying the same into effect is as follows:-Instead of
looking at the light through a magnifying lense or glass the light is
reflected or refracted, or both, upon an obscured surface, such as ground
glass or opal glass, the light falling or being focused upon such surface
as equally as possible, the object being to arrest and absorb the rays of 5
light upon this surface or disc of the lamp. On either side of this surface
(I prefer the outside) shades, say, of sheet iron, which have the various
characters cut in them, are moved, and in some cases fixed over the
illumined surface; the result will be a clearly defined object of the
character cut in the screen.
Various colors may be given to the illumined surface or characters
in the usual way, but I prefer the colored glass to be introduced between
the refracting medium and the obscured surface when practicable.
1
Another way of producing an illumined object on the obscured surface
is by using a series of lenses and slides in the same way as the magic 1
lantern, the disc of obscured surface taking the place of the usual
screen:
It will be at once seen by the practical mind that the above system
of giving distinguishing signals may be extended in various useful ways
to railway signalling, as well as for engine and tail lamps of trains, and 2
so forth, and an important and economical feature is that in many cases
it will diminish the number of lamps required, and also lessen the
liability to mistakes.
Another feature is that a very small burner will be sufficient to
illumine the disc of a lamp for a siding or other signal not required to be 2
seen a long way off, and being invisible or indistinct at a distance would
tend to give greater distinction between the various signals.
By my improved mode of enclosing the burner with the reflecting and
refracting. medium very little of the light escapes, the greater portion
being thrown upon and absorbed by the obscured surface or disc of the
lamp.
For a distinguishing day signal the obscured disc of opal will in many
cases be sufficient, as it will show white through the screen, and show
tho characters as the night signal.
In other cases the characters should be made. sav. in sheet iron fixed:

page_text: night signal in such a manner that as the signal arm is lowered to the
"all right" position the character would be raised over it into the place
occupied by the arm before it was lowered, so that in some cases one
arm and lamp will indicate several distinctive signals, and in other cases
one lamp can be made to indicate for several arms.
In cases when the home signal at one station is controlled as a distant
signal from the next in advance, as at present carried out, it frequently
causes misunderstanding and unnecessary blocking of a section of the
line when it might be occupied, the driver of a train not knowing
whether the signal that is against him is controlled for the home or the
distant signal, as according to the rules of most railway companies a
driver is authorized to pass a distant signal at danger and to slacken
speed, but to stop at a home signal in that position. I therefore make
such an arrangement that the cause of obstruction is removed and yet
retain the necessary controlling agency, so that a driver will be able to
distinguish both by day and night which signal is against him, the
arrangement to be somewhat as follows:-Instead of the single signal
arm being as heretofore equally controlled by each signalman I propose
to have two arms, one in front of and covering the other, the front arm
to denote the home and the rear the distant signal, the former to work
quite independently of the distant arm; the latter however cannot be
moved to "all right" until the home signal is lowered; the effect of
putting the home signal to "danger raises the distant likewise to
danger" if it be lowered, so that the operation of the home signal
controls the distant arm.
"
"
For the night signals, when both arms are at "danger," a red light
would be shown. When the front arm or home signal was lowered the
letter H, say in green, would be shown, indicating to the driver that it
was the home signal that was pulled off, and the distant arm at danger
indicating that he might pass the signal and draw up cautiously towards
the next. When both arms were lowered a white light would be shown,
indicating that the line was clear at both places.
The ordinary lamp may be used, with the spectacles so arranged that
a red, green, and white light may be given for the three indications in a
corresponding manner.
The signals being the principal and in many cases the only means of
communication between the drivers and the signalman it is obvious tha

page_text: they should denote all the information needed by the former without
confusing him with complications or uncertainty, therefore at junctions
or stations through which fast trains run, or in other cases where
necessary, I propose to make the distant signal with two arms, one
covering the other, the front one referring to the station, and the other
to indicate for the section of the line beyond or in advance, the former to
control the action of the latter, each worked by separate levers, so that a
driver on approaching a distant signal would know in good time whether
the line was blocked at the station or the section in advance of the
station, the arrangement for working the arms and the night signals to
be somewhat similar to that before described.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Samuel Telford Dutton in the Great Seal Patent
Office on the 13th September 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, SAMUEL
TELFORD DUTTON, of Worcester, in the County of Worcester, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Thirteenth day of March, in the year
of our Lord One thousand eight hundred and seventy-five, in the
thirty-eighth year of Her reign, did for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Samuel Telford Dutton,
Her special licence that I, the said Samuel Telford Dutton, my
executors, administrators, and assigns, or such others as I, the said
Samuel Telford Dutton, my executors, administrators, and assigns,
should at any time agree with, and no others, from time to time and
at all times thereafter during the term therein expressed, should and
lawfully might make, use, exercise, and vend, within the United
Kingdom of Great Britain and Ireland, the Channel Islands, and Islo
of Man, an Invention for "IMPROVEMENTS IN SIGNALLING ON RAILWAYS,
INCLUDING APPLIANCES USED THEREFOR," upon the condition (amongst others)
that I, the said Samuel Telford Dutton, my executors or administrators,
by an instrument in writing under my, or their, or one of their hands
and seals, should particularly describe and ascertain the nature of the

page_text: 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 I, the said Samuel Telford Dutton, do hereby
declare the nature of my 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 refers chiefly to arrangements for giving a distin-
guishing or a series of distinguishing signals from the lamps in the form
of numbers, letters, or words, and also in the mode of working signals
acted upon by different signalmen; also mode of acting distant signals.
Carrying the same into effect is as follows:-Instead of looking at the
light through a magnifying lens or glass the light is reflected or
refracted, or both, upon an obscured surface, such as ground glass or opal
glass, the light falling or being focused upon such surface as equally as
possible, the object being to arrest and absorb the rays of light upon the
surface or disc of the lamp. On either side of this surface (I prefer the
outside) shades, say of sheet iron, which have the various characters cut
in them, are moved, and in some cases fixed over the illumined surface,
the result being a clearly defined object of the character cut in the
screen.
Various colours may be given to the illumined surface or characters
in the usual way, but I prefer the coloured glass to be introduced between
the refracting medium and the obscured surface when practicable.
Another way of producing an illumined object on the obscured surface
is by using a series of lenses and slides in the same way as the magic
lantern, the disc of obscured surface taking the place of the usual
screen.
It will be at once seen by the practical mind that the abovo system
of giving distinguishing signals may be extended in various useful ways
to railway signalling, as well as for engine and tail lamps of trains, and
so forth, and an important and economical feature is that in many cases
it will diminish the number of lamps required, and also lessen the
liability to mistakes.

page_text: Another feature is that a very small burner will be sufficient to
illumine the disc of a lamp for a siding or other signal not required to
be seen a long way off, and being invisible or indistinct at a distance
would tend to give greater distinction between the various signals.
By my improved mode of enclosing the burner with the reflecting and
refracting medium very little of the light escapes, the greater portion
being thrown upon and absorbed by the obscured surface or disc of the
lamp.
For a distinguishing day signal the obscured disc of opal will in many
cases be sufficient, as it will shew white through the screen, and show
the characters as the night signal.
In other cases the characters should be made, say in sheet iron, fixed
to an arm moving on a centre and working with the slides, giving the
night signal in such a manner that as the signal arm is lowered to the
"all right" position the character would be raised over it into the place
occupied by the arm before it was lowered, so that in some cases one
arm and lamp will indicate several distinctive signals, and in other cases
one lamp can be made to indicate for several arms.
In cases when the home signal at one station is controlled as a distant
signal from the next in advance, as at present carried out, it frequently 2
causes misunderstanding and unnecessary blocking of a section of the
line when it might be occupied, the driver of a train not knowing
whether the signal that is against him is controlled for the home or the
distant signal, as according to the rules of most railway companies a
driver is authorized to pass a distant signal at danger and to slacken ?
speed, but to stop at a home signal in that position. I therefore mako
such an arrangement that the cause of obstruction is removed, and yet
retain the necessary controlling agency, so that a driver will be able to
distinguish both by day and night which signal is against him, the
arrangement to be somewhat as follows:-Instead of a single signal 3
arm being as heretofore equally controlled by cach signalman I propose
to have two arms, one in front of and covering the other, the front arm
to denote the home, and the rear the distant signal, the former to work
quite independently of the distant arm; the latter however cannot be
moved to "all right" until the home signal is lowered; the effect of 3

page_text: "
putting the homo signal to " danger raises the distant likewise to
" danger "if it be lowered, so that the operation of the home signal
controls the distant arm.
For the night signals, when both arms are at "danger," a red light
would be shewn. When the front arm or home signal was lowered the
letter H, say in green, or other letters, say D in red, as may be considered
best for that particular purpose, would be shewn, indicating to the
driver that it was the home signal that was pulled off, and the distant
arm at danger, indicating that he might pass the signal and draw up
cautiously towards the next. When both arms were lowered a white
light would be shown, indicating that the line was clear at both places.
The ordinary lamp may be used, with the spectacles so arranged that
a red, green, and white light may be given for the three indications in a
corresponding manner.
The signals being the principal and in many cases the only means of
communication between the driver and the signalman it is obvious that
they should denote all the information needed by the former without
confusing him with complications or uncertainty, therefore at junctions
or stations through which fast trains run, or in other cases, when
necessary, I propose to make the distant signal with two arms, one
covering the other, the front one referring to the station, and the other to
indicate for the section of the line beyond or in advance, the former to
control the action of the latter, each worked by separate levers, so that a
driver on approaching a distant signal would know in good time whether
the line was blocked at the station or the section in advanco of the
station, the arrangement for working the arms and the night signals to
be somewhat similar to that before described.

page_text: Fig. 5, vertical section of a lamp suitable for a siding signal, & being
the fixed screen with character cut in over the obscured surface e, a
smaller light without reflector being sufficient to illumine the object;
Fig. 6, front elevation of Fig. 5.
Fig. 7, front elevation of signal with one arm and lamp, but fitted
with screens for giving by day and night a series of distinguishing
signals. The arm is at danger, and a red light shewn.
Figs. 8 and 9 are front elevations of signals shewn in Fig. 7, with the
Nos. 1 and 2 screens raised in front of the lamp, and the arm lowered;
the operation of raising either of the screens lowers the signal arm. A 1
corresponding character to that in the screen may be shewn on the other
side clear of the signal post in the place occupied by the arm before
being lowered.
Fig. 10, front elevation of signal with three arms, say, referring to one
lino of railway diverging to three other lines, and so arranged that one 1
lamp distinguishes for the three arms on the signal.
Fig. 11 is another view of the same signal with the third arm lowered,
as shewn, and showing thereby the distinguishing screen (3) brought
over the disc of the lamp.
Figs. 12, 13, and 14, front clevations of signal fitted with distinguishing a
controlling arrangement. In Fig. 14 both arms are at danger, and a red
light shewn. In Fig. 13 the home signal arm is shown lowered and the
distant arm at danger, with the distinguishing screen over the lamp. In
Fig. 12 both arms are lowered, and the lamp shows an all clear light.
In these Figures j represents the home signal arm; k, the distant arm; 2
1, the spectacle with red glass working with home signal arm; m, the
intermediato distinguishing screen acted upon alternately by each of the
arms. The effect of lowering the home signal ; places the screen in
front of the lamp, and that of lowering the distant arms / to remove it.
Tho spindle to which the home signal arm is fixed is hollow, and that
for the distant arm & works through it. n is the balance lever actuating
the home signal, and controlling the distant signal arm fixed to the short
intermediate balance lever o, p being the balance distance lever.
Figs. 15 and 16, front elevations of ground siding signal, with distin-
guishing lamp and indicating disc.

page_text: Figs. 17, 18, and 19, enlarged views of lamps and screens for Figs. 10
and 11, f, f', and f³ being the screens; g, colored spectacle; h, the
disc; i, the refracting lens, with reflector enclosing the light.
Fig. 20 shews diagram sketch of station with distant, home, and
starting signals for up and down lines. The distant signals q and q¹ arc
shewn with the double arm arrangement, similar to Fig. 14. The home
signals and 7 and starting signals 8 and s¹ as usual. The object
intended is that the distant signals shall indicate the condition of the
home and starting signals, and whether the line is blocked at the station
or beyond. Taking the distant signal q' on the up line, one arm being
down, and the other up, indicates that the home signal is down, and
starting signal up, viz., station clear and section blocked. The signal q
for down line having both arms down indicates that the home and
starting signals are down, and the line clear through.
Having now particularly described and ascertained the nature and
object of the said Invention, and in what manner the same is to be
performed or carried out in practice, I hereby declare that I claim the
Invention of "Improvements in Signalling on Railways, including
Appliances used therefor," substantially as the same is herein-before
set forth and described, in which Invention the following are points of
importance :-
Firstly. So arranging the signal lamps that instead of using the usual
round bulls' eyes or lenses as the night signal mediums I give a
distinctive object in light in the shape of a figure, letter, or word,
thereby distinguishing one signal from another apart from its locality,
and to indicate the nature and position of the various sidings and other
points.
Secondly. Arranging the moving screens so that one lamp is used to
give a series of distinctive signals.
Thirdly. One signal arm arranged to give a series of distinctive signals,
as beforo described.
Fourthly. Arrangements in cases when one signal is controlled by two
or more signalmen, as the homo signal for one and the distance for the
other, and to give such a distinction to each operation that an engine
driver will know which signal may be against him, and yet to give the
necessary controlling to each of the signalmen,

page_text: And, Fifthly. Similar arrangements adapted for a double distant signal
o indicate, as before described.
In witness whereof, I, the said Samuel Telford Dutton, have.
hereunto set my hand and seal, this Tenth day of September, in
the year of our Lord One thousand eight hundred and seventy-
five.
SAMUEL TELFORD DUTTON. (L.S.)
Witness,.
ALFRED LUCADON WELLS,
London Road,
Worcester.