IMPROVEMENTS IN ELECTRICAL RAILWAYS AND TRAMWAYS
Year: 1883

page_text: LETTERS PATENT to William Acheson Traill Civil Engineer, of Portrush in
the County of Antrim for an Invention of IMPROVEMENTS IN ELECTRICAL
RAILWAYS AND TRAMWAYS
1
PROVISIONAL SPECIFICATION left by the said William Acheson Traill at
the Office of the Commissioners of Patents on the 2nd July 1883.
WILLIAM ACHESON TRAILL, Civil Engineer of Portrush in the County of Antrim
"IMPROVEMENTS IN ELECTRICAL RAILWAYS AND TRAMWAYS."
My Invention relates to an improved construction of electrical tramway or street
railway and it has for its object to prevent the possibility of horses or pedestrians
receiving shocks by coming into contact with the electrical conductor and to avoid
interference with the ordinary street traffic such as would be caused were the
conductor laid above the street level.
My Invention consists in enclosing the conductor, in an envelope or casing laid
beneath the ground by preference midway between the rails and provided with a
longitudinal opening to admit of one or more electrical contact arms projecting
from the car and travelling along in the casing in contact with the electrical
conductor. The said casing may be a cast iron tube having a narrow longitudinal
mouth or slot along its upper side enclosed between flanged lips that rise up to the
ground level. The contact arm that travels in this slot would be encased in a
protective sheath from which it would be insulated and would carry at its lower
end a spring contact piece (preferably of the form described in another application
for Provisional Protection of even date herewith) which would rub against the
side or top of the electrical conductor carried upon insulating supports within the:
tubular casing. The necessary provision would be made in the casing at junctions
with branch or other lines, and the casing would be provided with suitable
manholes and drainage outlets,

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said William Acheson Traill in the Patent Office on the 2nd January
1884.
WILLIAM ACHESON TRAILL, Civil Engineer of Portrush in the County of Antrim,
"IMPROVEMENTS IN ELECTRICAL RAILWAYS AND TRAMWAYS."
My Invention relates to an improved construction of electrical tramway or street
railway, and has for its object to prevent the possibility of horses or pedestrians
receiving shocks by coming into contact with the electrical conductor, and the
better to prevent persons from interfering with the same, and to avoid interference
with the ordinary street traffic such as would be caused were the conductor laid
above the street level.
My invention consists in enclosing the conductor in an envelope or casing laid
beneath the ground by preference midway between the rails and provided with a
longitudinal opening to admit of one or more electrical contact arms projecting
from the, car and travelling along in the casing in contact with the electrical
conductor.'
The said casing may be a cast iron tube having a narrow longitudinal mouth or
slot along its upper side enclosed between flanged lips that rise up to the ground
level. The connection arm that travels in this slot would be encased in a protective
sheath from which it would be insulated and would carry at its lower end a spring
contact piece which would rub against the top or side of the electrical conductor
carried upon insulating supports within the tubular casing.
In order that the invention may be more readily understood I have illustrated it
in the accompanying Drawings and will proceed to describe it with reference
thereto.
Figure 1 represents a cross section of the Tramway and the underground tube..
The casing A is by preference a cast iron tube of circular, oval or rectangular
section in lengths with socket ends for bolting together or united by thimbles, the
pipes being provided at the ends and intermediate points with sole plates B which
would rest on a suitable concrete foundation. There- would be also at the same
intervals wings C near the top surface, to which the tram rails would be secured
to preserve accuracy of gauge and also to prevent compression of the sides of the
longitudinal slit in the tube. The tube would be supported at intervals with
transverse struts E allowing a free passage underneath for water, so that the lower
portion of the tube would serve as a drain for carrying off any water or debris
which night fall-therein, suitable outlets F being provided leading into the street
drains. These struts would act as distance pieces to prevent the upper members of
the tube from being crushed in under a passing load. There are also manholes
at intervals for gaining access to the inside.. This tube may partly. be built of
sewer blocks in conjunction with the iron thimbles, the upper portions adjacent to
the slit being of metal, essentially as described. The space between the rails D.
and to the margin of the flanged lips P would be paved or laid with asphalt upon
a bed of cement.
t
The struts E above referred to would be formed with sockets H into which
would fit, or to which could be attached blocks I of insulite porcelain or other
insulating material supporting a bar J of T iron or copper band, continuous
metallic connection being maintained throughout by means of U shaped expansible
connections and fish plates. This rigid conductor would be placed a little to one
side of the longitudinal slit. In order that dirt or water in falling through would
not fall upon it, the stem K of the contact brush L being cranked to one side to
admit of the contact brush properly rubbing upon the conductor.

page_text: Figure 1 shows the ordinary arrangement of the tube and the enclosed conductor
with one conductor J along one side. A second conductor J¹ may be placed at the
corresponding opposite side and which may be kept charged by a second and
different electric current from an independent Generator, so that one series of cars
can be driven by one current and the return cars or another series of cars be driven
by the second conductor, or the second conductor may be used for a branch line
Tramway, the return current being carried through the tram rails or metal tube
and tram rails combined.
Figure 2 is a cross section of a modification wherein the tube has two longitu-
dinal slits containing two independent insulated conductors, which can be used
independently along the same line or where branch lines occur. In this case the
central portions E¹ of the struts E are continued up to support an iron trough M¹,
which can be screwed down to the upright pedestal E' and filled in with asphalt,
the flanged lips. forming the sides of the two longitudinal slits. This mode of
construction admits of the ready removal of this central trough for the purpose of
inspection or repairs without disturbing the stone paving.
Figure 1 shows the general arrangement with the Tramcar in position and the
manner in which the contact arm is connected with the car. In general there
would be two such contact arms placed immediately adjacent to and just outside
the axles of each pair of wheels, so that the relative positions of the wheels, contact
arm, and central slit would be preserved as nearly as possible even when going
round sharp curves.
The details of the arm and contact brushes are shown in Figures 3, 4, and 5.
The connecting rod K is a thin strip of steel some inches in width encased inside
an outer shield of steel O the edges of which are bevelled as in Figure 5, the two
portions being insulated from each other by an intervening insulating material.
The arm K is held by the outer casing between two hangers R underneath the
floor of the car so arranged either by two pins S or by being clamped into a socket
as to admit of sufficient lateral motion to accommodate the lateral oscillation of
the car whilst remaining rigid in the fore and aft direction. The lower extremity
of the arm is provided with a contact brush T in the form of an elliptical steel
spring (as described in the specification of letters patent of even date herewith)
provided with a steel shoe, whereby rubbing contact is made with the conductor
rail J. From the upper extremity of the arm K the current is taken off to the
dynamo working the car. The use of two brushes gives certainty of constant
metallic contact with the conductor, the rubbing contact being an essential
feature.
The advantage of the system is that junctions and branch lines are readily
provided for the conductor rail branching as required and the brushes passing in
either direction according as the points may be set and automatically conforming
themselves to any variations of loads on the cars or irregularities on the
conductor.
The system of propelling the cars is by preference that adopted in the Giants
Causeway and Portrush Electric Tramway, a dynamo machine being placed under-
neath the floor of the car between the axles. Commutator handles at both ends of
the car switch on the current through a number of resistance frames to the commu-
tator of the dynamo which by altering the position of the brushes gives motion
in either direction. the revolutions of the armature of the dynamo being
considerably reduced and communicated to the wheel axles by means of chain
gearing
Having described the nature of my Invention and the manner of performing
the same, I declare that what I claim as my Invention to be protected by the
hereinbefore in part recited Letters Patent is.
1st The general construction, combination, and arrangement of parts constituting
the electrical tramways or street railway, substantially as herein described and
shown in the Drawings.
2nd In the construction of electrical tramways or street railways, the employment

page_text: of a tubular casing for the conductor or conductors with an upwardly projecting
longitudinal flanged mouth which alone reaches to. the surface of the ground,
substantially as shown and described.
3rd The construction of the tubular conductor casing with internal bridge pieces
or struts to carry the conductors on insulated supports, substantially as shown and
described.
4th In a system of electrical tramways or street railways, the employment of
sheathed contact carriers attached to the car and provided with contact brushes
whereby essentially a self regulating rubbing contact is maintained with the
conductor constructed substantially as shown and described.
In Witness whereof I the said William, Acheson Traill have hereunto set my
hand and seal this twenty eighth day of December, A.D. 1883.
WILLIAM ACHESON TRAILL M.A. Eng. (L.S.)