IMPROVEMENTS IN RAILWAY SIGNALS
Year: 1882

page_text: LETTERS PATENT to Andrew White Tuer of Leadenhall Street in the City of
London and James Cleminson of Westminster Chambers in the City of
Westminster for an invention of IMPROVEMENTS IN RAILWAY SIGNALS
PROVISIONAL SPECIFICATION left by the said Andrew White Tuer &
James Cleminson at the Office of the Commissioners of Patents on the
10th May 1882.
ANDREW WHITE TUER of Leadenhall Street in the City of London and JAMES
CLEMINSON of Westminster Chambers in the City of Westminster, IMPROVEMENTS
IN RAILWAY SIGNALS,
The object of our invention is to obviate the risks which owing to prevalence of
what is known as color blindness attend the use on railways at night of signals a
proper understanding of which is dependent upon accuracy in distinguishing from
one another lights of two or more colors.
For this purpose according to our invention we give to every signal a distinctive
form or character such that one signal may be clearly and readily distinguished
from another signal regardless of color-Usually in carrying out our invention it
will be convenient to use white lights as being distinctly visible at greater
distances but we do not limit ourselves to white as various colors may be employed
so long as the signals have imparted to them a form or character clearly
distinguishable regardless of color.
Thus we produce signals by the employment of light in large masses in such
manner as to represent straight or curved lines or bands or devices such as letters
or numerals or other convenient forms affording a ready means of distinguishing
one signal from another signal. According to one arrangement of apparatus for
this purpose the semaphore arm of a signal of the usual type is formed as a box
provided with a mirror or other reflector of a powerful character at the back and
in front thereof a light or series of lights ranged in a row or rows. If a lamp or
lamps be used the front of the box formed as described can be fitted or glazed with
clear glass. If gas be used a series of gas jets, burners or lights can be ranged in a

page_text: row or rows before the above described mirror or reflector or where electric light
is available it can be employed according to our invention in the form of a line
band arc or ray, or lines, bands, or rays of any convenient character. In some
cases a white background such as a painted or enamelled surface may be employed
for the mirror or reflector, or we dispense with a background and arrange the
lights so that they can be seen from both sides of the semaphore arm.
Where a powerful light is not required we in some cases produce signals
according to our invention by the use of a signalling object such as a semaphore
or the like coated with phosphorescent paint such as that known as Balmains or
other phosphorescent substance possessing the property of exhibiting a luminous
appearance for several hours after exposure to light
According to another arrangement we provide the semaphore or other signalling
body with a piece or pieces of glass formed on the dioptric principle and so arrange
in relation thereto a suitable light or lights as to produce by reflection the required
signal. The light or lights used in conjunction with the beforementioned arrange-
ments of reflectors are according to another modification caused to swivel or rise
and fall or otherwise move with the semaphore arm or signalling body though
separate therefrom in such manner that the rays of such light or lights shall be
concentrated on the said signalling body and reflected therefrom.
It is evident that our invention under the foregoing arrangements can be readily
adapted to semaphore signals such as are now commonly used for signalling on
railways.
In carrying out our invention in other cases as for example in applying it to a
new railway it will usually be convenient to so construct and arrange the signals
that there will be exhibited a large white light of some convenient form to
indicate “all right" and another large white light of a different form to indicate
danger or "stop."

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Andrew White Tuer & James Cleminson in the Great Seal
Patent Office on the 10th November 1882.
ANDREW WHITE TUER of Leadenhall Street, in the City of London, and JAMES
CLEMINSON, of Westminster Chambers, in the City of Westminster. "IMPROVEMENTS
IN RAILWAY SIGNALS"
The object of our invention is to obviate the risks which owing to prevalence of
what is known as colour blindness attend the use on railways at night of signals
a proper understanding of which is dependent upon accuracy in distinguishing from
one another lights of two or more colours.
For this purpose according to our invention we give to every signal a distinctive
form or character such that one signal may be clearly and readily distinguished
from another signal regardless of colour.
Usually in carrying out our invention it will be convenient to use white lights
as being distinctly visible at greater distances, but we do not limit ourselves to
white as various colors may be employed so long as the signals have imparted to
them a form or character clearly distinguishable regardless of color.
Thus we produce signals by the employment of light in large masses in such
manner as to represent straight or curved lines or bands or devices such as letters
or numerals or other convenient forms affording a ready means of distinguishing
one signal from another signal.
According to one arrangement of apparatus for this purpose the semaphore arm
of a signal of the usual type is formed as a box provided with a mirror or other
reflector of a powerful character at the back and in front thereof a light or a series
of lights ranged in a row or rows.
If a lamp or lamps be used the front of the box formed as described can be
fitted or glazed with clear glass. If gas be used a series of gas jets, burners or
lights can be ranged in a row or rows before the above described mirror or
reflector, or where electric light is available it can be employed according to our
invention in the form of a line band, arc, or ray, or lines, bands or rays of any
convenient character.
In the accompanying Sheet of drawings Figure 1 shews in front elevation an
arrangement in which a semaphore arm A is employed the arm being raised and
lowered in the ordinary manner.
Figure 2 is a cross section of the same.
The arm A is in the form of a box the back being formed with a mirror a¹ or
other reflecting surface and the front consisting of a clear glass all
A number of oil lamps a a in a row afford the necessary light or illumination.
These lamps are arranged as shewn, to swivel on brackets, so that they may at
all times preserve a vertical attitude.
Figures 4 and 5 are enlarged views at right angles to each other of these
swinging or swivelling lamps a
Figure 3 illustrates in cross section an arrangement of semaphore arm whereby
light is shewn on both sides.
Two mirrors or reflecting surfaces a¹ a¹ are arranged back to back and two rows
of lamps or lights are employed one in front of each mirror.
Figure 6 shews another arrangement of semaphore arm in the form of a box.
In this case gas burners are used in lieu of oil lamps.
The connexion between the gas pipe b within the arm or box and the vertical
gas pipe b may be effected as shewn by a piece of flexible tube 6" or by an
ordinary knuckle joint.

page_text: Figure 7 shows an arrangement differing from the foregoing arrangements in
that electric lights are employed.
Incandesence lamps or lights f (which may be of any ordinary or suitable kind)
are shewn, but it is obvious that are lights of any convenient construction may be
substituted therefor,
In some cases a white background such as an enamelled surface or one coated
with luminous or other paint may be employed in lieu of a mirror or reflector ;
or we may dispense with a background and arrange the lights so that they can
be seen from both sides of the semaphore arm.
It is evident that our invention under the foregoing arrangements can be readily
adapted to semaphore signals such as are now commonly used for signalling on
railways.
In carrying out our invention in other cases as for example in applying it to a
new railway it will usually be convenient to so construct and arrange the signals
that there will be exhibited a large white light of some convenient form to
indicate all right" and another large white light of a different form to indicate
danger" or "stop"
"
A convenient arrangement for this purpose consists in arranging a perforated
shutter to slide in front of a light, such shutter having through it two holes of
dissimilar form such as a long rectangular hole and a round hole for example so
that the light will be seen through the one or the other according to the position
of the shutter or the shutter may be stationary and the light be movable.
In our provisional specification we stated that where a powerful light was not
required we in some cases produce signals according to our invention by the use of
a signalling object such as a semaphore or the like coated with phosphorescent
paint such as that known as Balmain's or other phosphorescent substance
possessing the property of exhibiting a luminous appearance for several hours after
exposure to light.
Also that according to another arrangement we provided the semaphore or other
signalling body with a piece or pieces of glass formed on the dioptric principle
and so arranged in relation thereto a suitable light or lights as to produce by
reflection the required signal.
We however consider that the arrangements hereinabove described and illustrated
are much more desirable in practice.
Having now described the nature of our said invention and the manner in which
it is to be performed or carried into practical effect we would have it understood
that what we claim is :-
1 The use for signalling on railways of signalling apparatus, constructed and
operating in such manner as to afford to persons in charge of trains the desired
indications such as "line clear" or "line blocked" or the like without its being
needful for such persons to distinguish between one color and another substantially
as hereinabove described and illustrated.
2 The use for railway signalling of a semaphore rendered visible by light
displayed within it, substantially as described.
3 The use in conjunction with a semaphore for railway signalling of lighting
apparatus connected thereto and movable therewith so as to make visible the
attitude of the semaphore substantially as described.
In Witness whereof I the said James Cleminson have hereunto set my hand
and seal this tenth day of November in the year of our Lord, one thousand
eight hundred and eightytwo.