Richmond dispatch. [volume] (Richmond, Va.) 1884-1903, 1885-08-09
Air-DriveD street-Cars.

ABOUT TWO years slnCe VIC ueSSiioou
q system of air-driven tram-cars which
was then about to be adopted on the
Caledonian Road line Of the London
Streets Tramway Company's system.
This was the Mekarski system, and the
car which was then experimental with
was put on for regular traffic, and was
worked on that line for about four
months, taking its turn with the
pair horse-cars. 1t was intended
then to displace the whole Of
the horse-worked cars on this line
by ten air-driven cars, but various de-
lays occurred which prevented effect
being given to this intention until the
present time. Now, however, arrange
ments have been completed, and the
first Of the series of cars will very
shortly be placed on the line for regu-
larly working, to be followed in due
course by the other nine which are be-
ing built. Since our previous notice,
however, several improvements have
been introduced into the details of the
air engines, which are now made upon
the compound principle. The high
pressure cylinder is 81 inches and
the low-pressure inches in di-
ameter, with an 8-inch stroke,
and through these the compressed
air from the reservoirs is sue
cessively used. Means are provided
by which the high-pressure air can be
used in the low-pressure cylinder if
necessary. The engine-house contain
ing the air-cempressing machinery is
situated at the Holloway-road end of
the tramwsy line, where there are boil
ers, engines, and pumps, by means of
which atmospheric air is compressed,
at a pressure of $50 pounds per square
inch, into reservoirs placed in the en-
gine-house. From these reservoirs the
air is conveyed to the tram-car through
charging pipes with proper couplings,
which are connected up for charg-
ing and disconnected when the reser-
voirs on the car-which are placed I'M
deIneath the platform-are charged to
the necessary pressure Tho principal
feature Of the system, however, is that
the air in passing from the reservoirs on
the tram-car to the cylinders Of the en-
CINE is conducted through boiling water
and steam at pressure Of sixty pounds
to the square inch, which is contained
in what is known as a hot-pot. This
hot-pot is charged at the COMPRISING
station while the car reservoirs are being
filled with compressed air. By this means
the heat which the air takes up during
its passage through the hot water not
only causes the air to expand, but
prevents the formation Of snow in the
cylinders and at the exhaust. The
working pressure in the high pressure
cylinder ranges from $50 pounds down
to so pounds per square inch, and
can be varied at will. There are eff
ficient brake arrangements, and all the
other requirements Of the Board Of
Trade have been amply met. The
first of the series of cars for the Gale
DOMAIN Road line was inspected last
Saturday at the Inventions Exhibition
by a number of gentlemen interested
in tramway locomotion. They were
received by Captain Clipperton on be-
half of the company, and the construc-
ton Of the engine and its workings
were explained by Dir. Harris, for Sir
Frederick Bramwell who is the engi-
neer to the Mekarski Company, but
who was unayoidably absent. The car
was run to and fro on short line in the
south promenade Of the exhibition, its
working powers being satisfactorily de-
monstrated over such severe curves as
could not occur in practice. We may
add that the tram'cars upon the Me-
karski system have been successfully
working on the tramway lines at Nantes,
in France, for the last six years.