IMPROVEMENTS IN THE PROPULSION AND CONSTRUCTION OF TRAMWAY ENGINES AND CARRIAGES, AND IN THE APPARATUS OR MECHANISM CONNECTED THEREWITH, WHICH IMPROVEMENTS ARE ALSO APPLICABLE TO MOTIVE- POWER ROAD ENGINES AND CARRIAGES
Year: 1872

page_text: PROVISIONAL SPECIFICATION left by William Stewart Taylor at the
Office of the Commissioners of Patents, with his Petition, on the
18th June 1872.
I, WILLIAM STEWART TAYLOR, of the City and County of Edinburgh,
North Britain, Civil Engineer, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN THE PROPULSION AND CONSTRUCTION OF
TRAMWAY ENGINES AND CARRIAGES, AND IN THE APPARATUS OR MECHANISM
CONNECTED THEREWITH, WHICH IMPROVEMENTS ARE ALSO APPLICABLE TO MOTIVE-
POWER ROAD ENGINES AND CARRIAGES," to be as follows, that is to say :-
My said Invention has for its object and mainly consists in the
driving or propelling of tramway engines and carriages by very high
pressed air as a motive fluid, immediately supplied from strong storing
and supplying receivers, carried on or along with the engine and carriage
to be driven by it, previously supplied or charged from the large primary
air pressure, supplying and producing magazines and their stationary
motive engines and force pumps and machinery placed at suitable fixed
stations, as from two to twelve miles apart along the line; all so as to
effect the propulsion of such tramway engines and carriages in a more
convenient manner for passing through cities without the use of horses

page_text: or requiring to carry heat, steam, or other motive fluid producing
apparatus with them than has been the case heretofore.
And the nature of my Invention consists all substantially and par-
ticularly according to the essential application thereof,-
First. In having an ordinary stationary steam or other motive-power
engine and air forcing pumps, with a large primary air pressure receiving
or charging magazine erected at convenient stations along the line of
tramways. The engines and air pumps work regularly or at times, as
required, and force and maintain the air at a high pressure (considerably
above that at which it is required to be charged into the receiver of the
carriage), as say, from thirty to sixty atmospheres within the magazine,
so that the high pressed air receivers carried with each tramway engine
and carriage for actuating them may be charged, as desired, when they
reach the stations.
When the air to be forced into the stationary supplying magazines is
damp it is by preference drawn through chambers or ducts provided
with the best ordinary means of drying it, such as by passing it through
or over layers of dry fibrous, porous, or other substances having an
affinity for the moisture, which would absorb or dry the damp or
moisture out of the air in its passage to or from the pumps, and at the
same time prevent dust or other injurious matter from entering with the
air into the magazine.
Both the stationary magazines and the receivers on the tramway
engines are made of the strongest material and of the best and lightest
construction and shape practicable to sustain the enclosed high pressed
air with safety and durability, and for this purpose they are preferred
to be made of solid or welded round tubes, or of double riveted long
small hollow cylinders of thin steel; as from an eighth to a quarter of
an inch thick, according to their diameter, which it is not at present
considered advisable should exceed fifteen inches, and inversely from
fifteen to thirty diameters in length. All the tubes in each case are
arranged in convenient spaces below the carriage or other convenient
space, either longitudinally or transversely, and strongly connected by
branches at their ends, so as to make one containing and high pressed
air supplying receiver or reservoir, furnished with a proper safety valve
and pressure guages, and the withdrawing ducts or pipes with properly
adjusted regulating or reducing valves, especially between the motive
engine and its supply vessel.

page_text: The carriage and engine are preferred to be formed in one, having the
passenger scats arranged longitudinally in two rows on the top and
inside below, much as in the ordinary omnibuses, having the inside seats
placed over the two driving and traction wheels, disposed on each side
in the middle part of its length, to sustain the weight equally, having
the springs placed either between the main axle box frame and the axle
boxes as usual, or between it and the carriage.
Although in some cases the engine may be made as a separate portable
traction engine to draw the separate passenger carriage after it the
two wheels on each side are directly coupled through crank or eccentric
pins and a straight parallel acting connecting rod, one pin on each far
wheel being made to project out beyond these connecting rods, and at
right angles to each other, so as to be directly connected by ordinary
crank driving connecting rods to the sliding cross heads and piston rods
respectively of their driving engines, the cylinders of which are preferred
to be of the outside horizontal class and arrangement, disposed below the
seats of the carriage in the horizontal line or plane through the axis of
both wheels. The engines being thus coupled at right angles through
the fore or rear axle and wheels, the periphery of the other or opposite
pair of wheels just clearing the fore ends of the cylinders. These
cylinders for an ordinary sized engine and carriage to carry from forty
to fifty passengers, with wheels about three feet in diameter capable of
rising a gradient of one in ten, would, by preference, be from sixteen to
twenty inches in diameter with a stroke of about twenty inches, which
going at seventy-four revolutions per minute would give a running rate
of about eight miles per hour, which speed may be regulated by a
governor or by a cut-off valve and hand link motion, as may be desired.
And if the receiver be made to contain, say one hundred and ten cubic
feet at one thousand pounds pressure per square inch in starting from
the supply station, this would enable the tramway engine to go from six
to twelve miles with the said supply of compressed air, according to
the weight of the whole carriage and power required and absorbed in
driving it.
It is preferred to have the cylinders of the engines and valve chests
cased (especially when the compressed air was not sufficiently dried),
and have heated air or water circulated through these close jacketed
spaces to prevent the formation of ice in these working parts or valve
ports, the heat and steam being supplied and kept up by a small, nearly

page_text: smokeless, coke oven and air or water heater, whichever was preferred,
which hot air or water currents might also be made to heat the air
receivers and also the passenger compartment of the carriage.
The air forcing pumps of the stationary engines may, when found
desirable, as when working at very high pressures, have jacketed spaces
surrounding them for a current of cold air to circulate through, to
prevent the overheating of the pumps and working parts, and in some
cases the stationary air magazines, and especially the motive receivers
might be lagged, or the latter might have casings round them for heating
them by steam or other hot fluid currents at the different stations. And
the heated air or a portion of the whole heated products of combustions
from the coke oven may be forced by a small pump for the purpose,
worked from one of the carriage shafts into the air receiver to assist in
heating and drying it, to prevent moisture or the formation of ice in the
receiver or duct and motive cylinders; the engine in descending gradients
would work this pump most economically.
For the purpose of turning corners, curves, and off-sets, a pair of light
steering wheels carried on their axle would be mounted at each end of
the carriage, so that the advance pair, whichever that may be for the
time being, could be lowered at pleasure by their bogic frame and a
screw or rack and pinion arrangement of gearing, so as to let the wheels
into the grooves of the tramway and steer the carriage through them
and any desired ordinary arrangement of hand steering wheel and gearing
fitted thereto.
Although the nature of these improvements has mainly been described
in reference to one special application, it will be evident that they are
susceptible of various modifications to suit particular circumstances,
without departing from the main or essential features thereof, either to
snit tramway rails or common roads as desired, or ordinary railways for
short distances.