Evening star. [volume] (Washington, D.C.) 1854-1972, 1893-01-31

THOSE ELECTRICAL EXPLOSIONS.
Capt. Rossell's Report Of His Investigation
| Of the Matter.
| WHAT HE LEARNED FROM OFFICIALS IN NEW
| YORK CITY, WHERE SIMILAR EXPLOSIONS HAVE
| OCCURRED-HIs SUGGESTIONS TO THE CON-
MIssIoNERs APPROVED BY THEM.
During the past few months Washington has
had several explosions in the streets
and manhole covers to underground conduits
have been thrown high into the air by the
shock, and in two instances, at least, persons
have been injured by the flying metal.
On Friday last, as set forth in The STAR,
| Capt. Rossell went to New York city for the
! purpose of studying the method in vogue there
| to prevent these explosions for the purpose Of
| laying the matter before the board.
| The report Of Capt. Rossell was handed to the
| Commissioners this morning the full text of
| which follows:
''ln view of the various explosions in man.
holes OF electric conduits that have occurred
within the last two three months l visited
the city of New York on Friday last for the
purpose of seeing what steps were being taken
In that city to prevent such occurrences.
Some time ago the explosions in New York Of
this character were frequent but of late they
have nearly disappeared. In consultation with
persons having knowledge Of the matters of
New York find that all, or nearly all, of these
explosions occur from collections of ilumi-
mating gas in the conduits or manho,es which
was ignited in some manner and thus caused
the explosions.
UNCERTAIN METHOD OF IGNITION.
As to the method Of ignition the ideas Of the
officials vary. They stated to me that in some
cases they were able to trace the matter up,
and in other cases the cause will probably re-
main unknown forever
1 was told by Col. Kerney, chief engineer of
the board Of electrical control of the city of
New York, that he thought some Of the explo-
sions were caused by sparks entering the man
holes through openings or crevices at the man
hole covers, these sparks being struck by shoes
of horses coming in contact with the stones of
the pavement. and in other cases that they were
caused by electric discharges from cables Of
high tension.
Col. Jamison, chief engineer Of the Consoli-
dated Electric and Telephone Company, told
me that some explosions had also occurred by
the careless use Of lighted candles. Statements
were made that at the time the electric con-
duits we're put down in New York CITY
the gas mains of the service pipes were found
in a very leaky and bad condition, and the
amount of gas permeating through the soil was
enormous. This gas found it's way with greater
or less rapidity into the manholes, and it MAS
necessary to remove the covers frequently to
relieve them.
HOW TO PREVENT THE EXPLOSIONS.
The methods adopted in New York city to
prevent these troubles is about as follows:
Air pipes varying in diameter from six to
sixteen inches are laid parallel and near to
every electric conduit, with brass pipes, leading
from them to every manhole. and at the ends Of
these pipes are put in small escape pipes. Air
is then forced into these pipes by means of
blower, the Root blower being used in prefer
ence in that city.
The air is kept in these pipes and in the man
holes by connections with these blowers, at a
pressure of one-quarter to three-eighths of
pound per square inch. this being greater than
the pressure in the gas pipes. The blowers are
kept in use day and night continuously.
The city is divided into districts of COM
paratively small sizes. and gangs of men under
foreman are continually going over the
ground. examining for the presence of gas
in the manholes and removing the covers of
the manholes to relieve them from anv gas
that may have collected. Wherever anv odor of
gas is found, all tine gas companies are notified
at once, and are reqgired to take steps to stop
any possible leak i'll that vicinity BY these
means the explosions have almost disappeared
at the present time in New York city.
New York city has Of underground conduits
for electric wires at the present time probably
more than 200 miles, and believe stands at the
head in this matter in the United States.
CAPT. RossELL's SUGGESTION.
would advise the Commissioners that, in
my opinion, many of the old gas mains of the
Washington and Georgetown Gas Light Com
panies will be found leaky, and that it will be
necessary wherever the odor of gas is detected,
or its presence in any way observed. that
the companies be notified to at once examine
into and repair any defects that may be found
in their pipes. 1t would be In my opinion ask
tons Nf
ing and digging up OF our streets.
The electric companies, including the light
ing companies and the telephone companies
should be required to ventilate all their con-
duits and mauholes, either by the method
used In New York or by some equally service
able one, and notice should be sent to these
companies at once requiring them to make
such construction as will give the proper VEN
tilation to their corduits, the plans for such
construction to be submitted to the board Of
Commissioners for their approval before the
matter is undertaken.
Until the construction can be finished how
ever, 1t Will be necessary TO require the electric
companies to remove their manhole covers at
frequent intervals, SO as TO avoid the collection
Of any amount of gas at these places. and l
would suggest that police regulation be passed
by the board in the following Ianguage
All companies owning operating under
ground conduits containing electric wires
shall provide for the conduits and their ap-
purtenances such means OF ventilation as
shall meet the approval Of the board of Com
mssioners of the District of Columbia, to
prevent the accumulation of explosive gases
in said conduits. and until such means of VEN
tilation provided they shall be required to
keep constant supervision over their lines
with reference to the collection Of gases in
the manholes, and remove manhole covers at
sufficiently close intervals to prevent explosive
sccumulations.
recommend that the board at once COM
municate to these companies their views on
this matter and enforce the regulation at the
earliest practical moment"
The Commissioners unanimously approved
the report and the recommendations.
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