Intermediate Sidings

8/14/2019 Intermediate Sidings

1/14

Concepts of Signalling

Intermediate Sidings


2/14


Sidings taking off from passenger running

lines outside station limits (i.e., in the Block

Section) are called Intermediate or OutlyingSidings

SEM 7.75, 7.76 and 7.77 cover the

requirements of such siding points


3/14


Minimum Points equipment at siding points

on single line sections:

A gauge tie plate where steel sleepers are not

provided

A Facing Point Lock the plunger of which shall

lock each switch independently

Control of Points shall be by a key whichshall prove the setting and locking of Points

for the running line. This key shall be

interlocked with the Block Instruments


4/14


Minimum Points equipment at siding pointsin the facing direction on double line

sections:

A gauge tie plate where steel sleepers are notprovided

A Facing Point Lock the plunger of which shall

lock each switch independently

Control of Points shall be by a key which

shall prove the setting and locking of Points

for the running line. This key shall be

interlocked with the Block Instruments


5/14


Minimum Points equipment at siding points

in the trailing direction on double line

sections:

A gauge tie plate where steel sleepers are not

provided

A Key Lock the key of which can only be

extracted when points are set and locked for therunning line

Points shall be controlled through the Block

system in force


6/14


Provision of Markers and Signals:

These depend on the sectional speed.

Where sectional speed is upto 50 kmph, no

Markers and boards are required


7/14


Provision of Markers and Signals:

These depend on the sectional speed.

Where the sectional speed is more than 50 kmph,an S marker at the Points and a Speed Indicator

board (indicating 50 kmph) at 30 m from the

points will be provided in the facing direction. A

Caution and Termination Indicator shall also beprovided

In the trailing direction, only the S Marker at

Fouling mark is provided


8/14


S

50

30 m800 m (min)

T

Train Length


9/14


Where speed more than 50 kmph is to be

allowed over the facing points (para 166 d of

SEM 1955),

Point equipment as per para 144, and a stop signal adjacent to the points detecting each

switch and facing point lock, and

a warner or distant or warning board at EBD in the

rear shall be provided


10/14

Intermediate Sidings Some important points:

Speed restriction of 50 kmph is only in the

facing direction.

No speed restriction in the trailing direction

Intermediate Sidings are always provided with

isolation. A trap indicator is provided but is not

lit at night.All bolts, studs, pins etc. of apparatus used for

locking and control of points shall be rivetted to

prevent unauthorised interference


11/14


Some more points:Responsibility for operation of siding points

rests with the Guard of the train

After shunting the train into the siding, the

points are again set for the main line and

normal block working can be restored

This is achieved by special type of block

instruments and keys interlocked with blockinstruments


12/14


Operation of Intermediate Sidings:Points are controlled through the Block System

On single line, the key for the points is released by

the token

On double line, the key for siding points is released

when Instrument is in TOL position

Double Line Block Instruments with occupation key

are also available. This key locks the BI in normal,when taken out. It is given to the Guard, who, after

putting the train into the siding, returns the key to

the station through EKT. The BI can then be

unlocked to resume normal Block working.


13/14

Intermediate Sidings Operation of Intermediate Sidings:

On single line, Token-Key Exchangers are used

The Exchanger at the station has one token and no Key

locked into it

The Exchanger at the Siding has no token and a Keylocked into it

The ASM obtains LC and takes out a token from the BI.

It is given to the Guard, who, after reaching the Siding,

puts the token in the Exchanger and takes out the Key.This is used to unlock the siding points. After putting the

train into the siding and normalising the points, he

returns the key to the station through EKT. The ASM

uses the Key to release the token in the Exchanger. The

BI can then be normalised by using this token.


14/14

Intermediate Sidings Operation of Intermediate Sidings:

The procedure is reversed when the train has to come

out of the siding.

Another arrangement is to use an auxiliary BI

between the Parent station and the Siding. The tokensare identical but ABI is out of phase so that token

cannot be extracted from it. A train takes normal

token from main BI from any station. At the siding,

the token releases the key for operating the points.

After the train is placed in the siding, the key isdeposited back and the token is released. The token is

deposited into the ABI at the siding which enables a

token to be taken out from ABI at the station. This is

then used to normalise the main BIs.

Intermediate Sidings

Documents

Transcript of Intermediate Sidings