Evening star., 1902-08-22
ELECTRIC CAR FIRES
PAST AND PRESENT CAUSES
METHODS OF PREVENTION.
Frequent and Systematic Inspection Of
Rolling Stock Should Be
Made.

| From the New York Tribune.
An electrical engineer In this city who
has had occasion to watch the working OF
trolley ard elevated railway cars was
| questioned yesterday concerning some OF
the accidents which have recently occurred
In this and other cities. Some OF these,
especially the wrecking of runaway sur
face cars, he said. were entirely independent
/ OF the form OF motive power Ii is not
quite fair to hold electricity responsible for
| a broken chain, for Instance. A defect OF
| that character is purely mechanical, and IL
would be discovered IL there was a proper
! inspection of rolling stock.
On well-managed roads there II n sys-
| tematic examination of cars after they are
| run Into the barn. even when no necessity
for repairs Is reported by motorman or con-
| dIctor But there is great difference in
! railway companies In the thoroughness
with which they have that sort of work
| done. When a heavily loaded car a steep
grade becomes unmanageable. and either
jumps the track or overtakes and strikes
another car. the fault is usually with the
brakes. 1t Is fair inference that these
have either been carelessiy inspected or not
| inspected at all.
Difference in Brakes.
Brakes when In good order, though. are
not equally efficient. One who has noticed
the abruptness with which cars on the
Metropolitan street railways principal lines
are brought to a halt, and the more gradual
way in which many suburban cars are
stopped. might be puzzled by the difference
| In both cases. no doubt. the brakes work
| on the same general principle but the lever
/ age may be made greater In one than In the
| other. and hence the same expenditure of
muscle gives quicker results. Many at
| tempts have been made to perfect an elec-
| trio brake. Devices of the latter charac acter
lint fhsRr not oil
gether satisfactory. One which is In service
| over in New Jersey operates only while the
| car is moving.
The current from the overhead wire hay,
| ing been shut off by the motorman and the
| electric brake having been brought into
play, the electricity necessary to make it
adhere to the wheels is developed by the
! mechanism under the car. For the time
| being the motor is converted into dyna-
no. and the dynamo is driven by the rota-
| tfon of the car wheels. The instant the car
| stops, Of course. the supply of current from
this course stops, and the brake loses Its
grip. If the car is a bit OF level track
| 1t Will remain stationary, but on a grade
the electric brake will not keep IL still. All
| original momentum having been checked
the would alternately start ahead and
stop through a resumption of activity In the
brake. This alienation would continue
| until the foot of the hill was reached. The
electric brake is not useful resource In
emergencies, and is usually supplemented
by an ordinary hand brake.
Reversal of the Motor.
The chief reliance when a sudden stop is
necessary is a reversal OF the motor that
drives the car The motorman first shuts
of his power In the usual way, moves O
separate lever on the controller" box be-
fore him and then turns on his current
again. He is instructed to employ this
plan at critical moments, but he is also
familiar with the order to be careful about
a los ha
by overhead and ruin his motors Hence
he may be too cautious in reversing. Again,
the success of that practice is dependent
on retaining connections with the over
head wire. If the trolley is thrown or
reversing is without effect If the brake
| falls, too, the car becomes a hopeless VIC
| tim of the law of gravitation.
The most common type of accident on
| electrically operated elevated roads Is prob
| ably the burning of car or train. The
most disastrous case of this kind occurred
In Liverpool year so ago on Christmas
eve. The cause of that particular accident
Is known with some degree of accuracy.
The motors under the car which first took
fire were old and had been repeatedly re-
paired. Owing to some fault in the insu-
lating material the electricity was able
to follow a different route from the proper
one. The new channel permitted more than
the proper amount of current to pass An
arc or blaze resulted, and this ignited the
adjacent woodwork.
Use of Asbestos.
To meet danger from that source motors
are usually inclosed in a metal shell.
These are 'ironclad." Further protection
is being afforded to line OF cars built
to run under the Mersey from Liverpool
to Birkenhead by sheathing the wooden
car floor just above the motor with "as-
bestos slate" Perhaps further develop
ment of the fire-proof idea, here embodied,
may yet be deemed wise Mr. Westing-
house once went so far to suggest maxi
ing the whole fireproof This, OF
course, would not be necessary IL fire could
be prevented at all points where 1t was
likely to break out.
Now danger is to be anticipated from
car. Even il the motor Is all right, a fuse
may be blown out by an excessive amount
of current. A small blaze is genera ted
here, which may or may not spread The
modern equipment of elevated railway cars
however, does away with the fuse and SUBJ
stitutes what is called a circuit breaker
This performs the same functions as the
fuse. 1t shuts off the current automatic
cally in case Of excess. But Il is so in
closed with metal that one spark at that
point cannot do any harm.
Although two of the most important
causes Of fire have now been removed. and
the danger greatly reduced, trouble neyer-
startlngly suggestive way. Ii is the more
veXatious because the origin cannot always
be discovered. Sometimes the most that
can be known is the point of the outbreak.
which Is generally in the machinery. But
the precise nature of the defect cannot AL
ways be told with certainty. The fire de-
stroys the insulating material so complete
ly that one cannot say just how il looked
before.