The morning times., 1895-07-21
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CEMENT COHcaETe

AT first by engineers whether the system
could be made TO operate on long roads,
but the trial OF the Clay street line finally
demonstrated the success OF Halladie's
To the layman the power houses, con-
tanning the machinery which runsthc ca BILE,
is undoubtedly the most interesting part Of
the system. This machinery consisting
in principle Of an immense steam engine
which turns the drums or series OF drums
ar ound which the cable passes Seems
simple enough, but IN practice it is some what
complex.
THE BIG FLYWHEEL.
The driving plant Of the Washington
and Georgetown Railroad, on Pennsylvania
avenue between Thirteenth-and-a-half and
Fourteenth streets northwest. is n sample
of the power houses used by the different
roads in the country, varying OF course ID
magnitude. There the piston from an I'M
mense CoTliss engine turns big iiywheel
weighing fifty-siX tons and measuring
tweDty-four feet in diameter, and revolving
at the rate Of sixty-six revolutions a
minute. Geared upon the same shaft with
this fly wheel is drum four
teen feet in diameter, connected by
cotton cables with another drum thrt y-two
feet in diameter. A pair Of wheels around
which the street cable passes, and from
which il gets its power, are geared ON the
shaft with this drum.
The cotton cables connecting the engine
Shaft drum with the driving shaft drum
are made in England, and when in use
look very much like wire and are thought
by observers TO be a part OF the ca bic
which runs in the street. They are simply
used however, in place of the big leather
belts that are used 10 communicate power
from one wheel 10 another in ordinary ma
chinery, and their Preference is due TO
the fact that they are comparatively noise
less. Twelve, fifteen aud even thirty cables
are used to connect some of the drums.
The cable after passing around the driv-
ing drums before starting on its journey
through the streets Is Strengthened out b1
an arrangement Of weights, and its tension
is always kept the same, no matter what
the pull il may be subjected TO by the cars.
Every time grip loosens its hold OF the
cable the pull on the rope is reduced, and If
il were not for the system OF weights 10
keep il tight there would frequently be
very announcement slack in the long mass OF
steel wires
There are several devices of this kind in
use IN various cities, but the one used
here is probably the simplest and most eI
fective. consisting Of movable carriage
attached TO a wire cable at the other end
oil which are ldHltItu iluEt tlE IAS cO "a
ranged as TO rise and fan according 10 the
pull on the street cable, which is pulled
back by the carriage and the force OF tn
weights " hen there is slack, and Outw hen
taut.
ADVANTAGES OF QUICK TRANSIT.
The cable road possesses innumerahle ad
vantages over the old horse car roads. In
the first place with the cable road the City
can keep cleaner and better streets. They
run much faster than horse cars, and the
waits between cars arenot so interminable
At first in rapid transit there was great
danger to life and limb, but this has bee
reduced to n minimum in washington by
the adoption of adequate safety devices.
As q paying enterprise, it is evident tC
even the casual beholder that the cable
road is more profitable to the company tha
the horse cars. The first outlay for the
plant is OF course enormous, the average
cost of construction being about $50, ,00C
mile. but the deteriOrationlnthe machinery
is slight, and the average operating eX
penses after the road is completed, art
about s 4 cents per car and per mile The