Iowa County democrat. [volume] (Mineral Point, Wis.) 1877-1938, 1885-08-14
Air-Driyen Street. Cars.

About two years since We described
a system of irdriven tram-cars
which was then about to be adopted
on the Caledonian road line of the
London Street Tramway Company's
system, and the car which was then
experimental which was put on Cor
regular traffic, and was worked on
that line for about four months, TAX
ing its turn with the pair horse cars.
It was intended then to displace the
whole of the horse worked cars on this
line by ten air driven cars, but various
delays occurred which prevented eff
feet being given to this intention UNI
til the present time. Now, however,
arraa gements have been completed
and the first Of the series of cars will
very shortly be placed on the line for
regularly working, to be followed in
due course by the other nine which
are being built. Since our previous
notice, however, several improve"
ments have been introduced into the
details of the air engines, which are
now made upon the compound princi>
pie. The high pressure cylinder is
81 inches and the low pressure s inch
es in diameter, with an S-inch stroke,
and through these the compressed air
from the reservoirs is successfully
used. Means are provided by which
the high pressure air can be used IN
the low pressure cylinder if necessary.
The engine house containing the
air COMPRISING machinery is STU
ated at Holloway road end
Of the tramway line, where there are
boilers, engines, and pumps, by means
of which atmospheric air is compress
ed, at a pressure of $50 pounds per
square inch, into reservoirs placed in
the engine house. From these reser~
voirs the air is onVeyed to the tram
car through charging pipes with
proper couplings, which are connect-
ed 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 CON
Quoted through boiling water and
steam at pressure of 60 pounds to the
square inch, which is contained in
what is known as hot-pot. This hot
pot is charged at the COMPRISING
station. while the car reservoirs are
being filed with compressed air. By
this means the heat which the air
takes up during the 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 cyclinders ranges from
$50 pounds down to fifty 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 the
other day at the Inventions Exhibi-
ton by a number of gentlemen inter
ested in tramway locomotion. They
were received by Captain Clipperton
on behalf of the company, and the
working were explained by Mr.. Har-
ris. for Sir Frederick Bramwell, who
is the engineer to the Mekarski Conn
pany, but who was unavoidably alb
sent. The car was run to and fro on
a short line in the south promenade
of the exhibition, its working powers
beng satisfactorily demonstrated over
such severe curves as could not occur
in practice. We NAV 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.