The New York herald., 1879-03-10
RAPID TRANSIT CROSSINGS.

PATENT SWITCHES AND SIGNALS CLAIMED A.
GUARANTEES OF SAFETY AT POINTS OF
DANGER-THEIR APPLICATION IN ENGLAND.
To EDITOR HERALD
In your vigorous editorial article Of the Sd Of
March on rapid Transit Crossings" and in the
various articles and paragraphs which you now SO
frequently publish concerning the Il" roads. you
are doing what accustomed to expect you to
do-you are maintaining the interests OF the unor-
ganized public against the interests of powerful
organizations. In this particular of the Chat
ham square crossing there is. however. something
to be said on the side Of the organizations.
The gst of your article is that the arrangement Of
tracks in Chatham square. as proposed by the COM
panies. will be SO simply murderous" as to out
weigh all its advantages. Now it will be but just to
the companies to briefly explain to the public the
means adopted for the protection of that crossing.
This will be done by the mechanical interlocking Of
switches and signals, by the system now in use at
the junction Of Fifty third street Sixth avenue
at Rector street. and to be applied ut the juno
ton OF Fifty-thrd street and Ninth avenue, and at
various other points the Metropolitan Elevated
Railway.
Briefly. the interlocking system substitutes mech
anism for human intelligence; it eliminates.
far as may be, will, Judgment and the senses from
the problem of working traffic safely past danger
GUS point The movement OF trains past point like
the Chatham square crossing is governed by signals.
the disposition of which is determined by men ex-
after careful
locality and traffic.
These signals and the switches of the system un-
der their control all moved by levers placed in
row in one solid frame in q commanding position.
Each lever Is connected with its respective
switch or signals by rods and cranks. and the
levers connected with each other that the
movement of any one lever may be made lock
immovably any other lever levers. 1t will be
seen that the act of moving a lever to set a switch
or lower signal may at the same time make it i'm
possible to move any other switch signal until
the lever has been restored to its first position thus
ha ,ioa11p .ot
position Of the switches should be at any time con-
Trajectory to the position of the signals that in
compatible signals should be given. This system
capable OF indefinite extension. l quote from
Hallway Appliances" by John Wolfe Barry.
"At Cannon street station. where there seventy
switch. and signal levers concentrated in signal
house. the number of combinations which would 10
possible II the levers were not inerocked can be ex-
pressed only by millions OF these only sos combna-
tons safe and by the interlockng apparatus these
S0S combinations rendered possible and all tho
others impossible. II man were to go bndfold
into signal box with an interlocking apparatus he
might SO far as accordance between switches and
signals is concerned be allowed with safety to null
any lever ut random. He might delay traffic. be-
cause he might not know which signel to
lower for particular train; but he could
not lower such signal produce such
combination OF position of switches and signals az
would IL the signals were obeyed. produce u coli
lision." And an engineman knows that. under q
positive and unerring system any disregard Of sig
Archibald Dawney. Associate Institute Civil En-
gineers. writing i'll 1874 Of the same station says
that 6OJ trains daily worked east and west and
vice versa with no difficulty other than the manual
labor necessary to open and close the road with
sufficient expedition to avoid delays.
AT the Moorgate Street Station. Metropolitan Rail-
way, London, the total number of trains using the
station on working day of nineteen hours is 76S.
'As each arriving and departing train requires .
separate movement Of the engine for changing from
end OF the station to the other this gives total
OF 1886 movements of engines on the four lines Of
way in nineteen hours Tor very nearly every
fortyhve seconds) and every movement is separately
and distinctly signalled." "Rapier on Railway Sig
nals Proceedings of the Institute Civu Engineers.
London, 1874
cite these instances to show how enormous and
complicated traffic has been safely handled for years.
The writer's above quoted discuss the subject at
length. Fifteen interlocking apparatus in sue
cessful operation in the United States to-day, and
the best of them perfect in their action that
signalman cannot even commence to make any move
ment of switches signals until he has efficiently
locked in their proper positions all switches and
signals which have any relation to the movement
which he intends to make Moreover, all signals
arranged that in of any accident to apparatus
connections they go to danger. Thus 1t will be
that even Chatham square crossing will be pro-
tccted by signals which cannot err mislead, and
that SO long those signals obeyed even 'Saugh
ter Place will be safe as any point the lines
FAIR PLAY.