Wood County reporter. [volume] (Grand Rapids [i.e. Wisconsin Rapids], Wis.) 1857-1923, 1885-09-03
A.r-Driyen Street-Cars.

About two years since, says the Lon
don Times, we described system of
air-driven tram-cars which was then
about to be adopted on the Caledonian
road line OF the London Streets Tram
way 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
for about two months, taking its turn
with the pair of horse-cars. 1t was in
tended then to displace the whole of
the horse-worked cars on this line by
ten alr-drlven 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-
lar working, to be followed in due
course by the other nine, which arc 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 five and a quarter
inches, and the low-pressure eight
inches in diameter, with an eight-inch
stroke, and through these the COM
pressed 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-compressing machinery is
situated at the Holloway road end of
the tramway line, where there are
boilers, engines, and pumps, by means
of which atmospheric air is compress
ed, at pressure of 450 pounds per
square inch, into reservoirs placed in
the engine-house. From these reser-
voirs the air is conveyed to the tram
car through charging pipes with prop
er couplings, which are connected up
for charging and disconnected when
the reservoirs on the car-which are
placed underneath the platform-are
charged to the necessary pressure.
The principal feature of the system,
however, is that the air in passing
from the reservoirs on the tram-car to
the cylinders of the engine is conduct
ed 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 fill
ed 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 pre-
vents 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 efficient
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 Caledonian road
line was inspected recently at the in
ventions exhibition by number of
gentlemen interested in tramway To-
comotion. They were received by
Capt. Clipperton on behalf of the COM
pany, and the construction of the en-
CINE and its working were explained
by Mr.. Harris, for Sir Frederick Bran
well, who is the engineer for the Me-
karski company, but who was unavoid-
ably absent. The car was run to and
fro on a short line in the south prom
enade of the exhibition, its working
powers being satisfactorily demonstrate
ed over such severe curves as could
not occur in practice. We may add
that the tram-cars upon the Mekarski
system have been successfully working
on the tramway lines at Nantes, in
France, for the last six years.