IMPROVEMENTS IN THE CONSTRUCTION OF ELEVATED STREET RAILWAYS, TRAMWAYS AND ROADWAYS
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by Alexander Melville Clark at the
Office of the Commissioners of Patents on the 7th September 1883. Communi-
cated to him from abroad by the firm of Milinaire frères of Paris, France.
ALEXANDER MELVILLE CLARK of the firm of A. M. and W. Clark of 53 Chancery
Lane in the County of Middlesex, Fellow of the Institute of Patent Agents,
IMPROVEMENTS IN THE CONSTRUCTION OF ELEVATED STREET RAILWAYS, TRAMWAYS
AND ROADWAYS' [communicated to him from abroad by the firm of Milinaire
frères of Paris, France]
"
This Invention relates to the construction of a two storeyed elevated street
railway, tramway, or roadway, the up and down lines of traffic being superposed
in order to reduce the width of the structure to a minimum. At the terminal
stations hydraulic or other lifts would be provided to transfer the trains or the
carriages from the one to the other line.
In order that the construction of the two storeyed elevated rail tram or roadway
may be more readily understood, I have illustrated an example thereof in the
accompanying drawings and will proceed to describe it with reference thereto.
Figure 1 is a side elevation of the structure supported on a single central row of
columns, and Figure 2 is a cross section thereof showing the superposed roadways
each laid with an ordinary two rail railway. Figure 3 represents a side elevation
of a hydraulic lift for transferring the vehicles from one road to the other. Figure 4
represents a side elevation, and Figure 5 a cross section of a similar structure
specially designed for a single-rail tramway, these figures also illustrating the
construction of the carriages travelling thereon.
Referring to Figures 1. 2. 3 in which the same letters indicate the same parts,
a are the columns bedded on foundations of masonry laid in hydraulic cement or on
cast iron blocks, the base of the columns above the ground level being of such form as
to occupy as little of the width of the ordinary road way and leave as much space
between consecutive columns as possible. These columns may be cast in one or
more sections, or they may be constructed of wrought iron and filled with concrete
so as to ensure the necessary strength for a small diameter.
The superstructure is similar in construction to railway bridges of the lattice
Union C21

page_text: girder type, and consists of two main lattice girders c placed at a sufficient distance
apart for a single line of traffic. To the upper and lower members of the main
girders are bolted cross girders d to support the rail or tramway rails f, the spaces
between the cross girders being filled by brick arches in the case of roads for
ordinary vehicles, or tied together by longitudinal girders g or by the rails f, and
at either side of the track, or over the whole width a plank floor laid close together
or suitably spaced.
The upper track is at the level of the upper members of the main girders c and
is supported by similar cross girders d', the intervening spaces being filled with a
floor of brick, iron, or wood. k are hand rails fixed upon the main girders c.
Access is had to each track by gangways leading from suitable waiting rooms
situated at the sides of the street, on the foot paths for example.
The rolling stock is transferred from one road or track to the other by means of
lifts operated in any suitable way and constructed as shown in Figure 3, or
otherwise,
Referring to Figures 4. 5. 6 in which the same letters also indicate the same
parts, a are columns of cast or wrought iron or masonry of circular, oval, polygonal,
or other section and resting upon a suitable foundation. b is a central longitudinal
arched or straight girder resting on the columns a and upon which is laid the
single central elevated rail of the lower track. c are cantilevers or brackets bolted
upon the columns at right angles to b and supporting cross girders & upon the ends
of which are fixed the lattice work uprights e from which spring the arches ffl of
lattice, box, or plate girder form. The lower series of arches f support and are tied
by a central longitudinal girder / which serves to guide the carriages running on
the lower track and to support the upper track or rail. This girder h may be of
lattice, plate, box, or other form. The upper series of arches f¹ are tied together
by a lattice or other girder & which ensures the necessary rigidity and serves as a
guide for the vehicles running on the upper track. nn' are Tiron ties or struts
abutting respectively upon the cross girders d and upon the columns o. 7 are
balustrades fixed along a light footway supported by the longitudinal girders
b and h.
The construction shown in Figure 6 is modified with a view to diminish the
height of the structure and afford greater clearance for the passage of the vehicles.
The construction of the carriage used on this single rail tramway consists of a body
with longitudinal benches m placed back to back at either side of a longitudinal
central partition and with doors p at the sides. The vehicle is supported upon two
running wheels o one at each end situated in the centre line of the vehicle between
the benches m and running on the rail as shown and is kept upright by pairs of
guide rollers q mounted on the roof and embracing a guide rail.