Full Site Search  
Tue Apr 25, 2017 08:15:00 IST
PostPostPost Trn TipPost Trn TipPost Stn TipPost Stn TipAdvanced Search
What is Interlocking work? What are the Types of Interlocking?  
3 Answers
Apr 06 2013 (11:27)

Entry# 1531     
S V Iyer*^~
What is Interlocking work? What are the Types of Interlocking?

Apr 06 2013 (11:26)
Blog Post# 715271-1     
S V Iyer*^~   Added by: S V Iyer*^~  Apr 06 2013 (11:27)
In railway signalling, an interlocking is an arrangement of signal apparatus that prevents conflicting movements through an arrangement of tracks such as junctions or crossings. The signalling appliances and tracks are sometimes collectively referred to as an interlocking plant.

A minimal interlocking consists of signals, but usually includes additional appliances like switches / Points, derails, crossings at grade and movable bridges. Some of the fundamental principles of interlocking include:

1. Signals may not be operated to permit conflicting train movements to take place at the same time.

2. Switches and other appliances in the route must be properly 'set' (in position) before a signal may allow train movements to enter that route.

3. Once a route is set and a train is given a signal to proceed over that route, all switches and other movable appliances in the route are locked in position until either
a. The train passes out of the portion of the route affected, or
b. The signal to proceed is withdrawn and sufficient time has passed to ensure that a train approaching that train has had opportunity to come to a stop before passing the signal.

Apr 06 2013 (11:28)
Blog Post# 715271-2     
S V Iyer*^~   Added by: S V Iyer*^~  Apr 06 2013 (11:28)
The Benefit:
Interlockings allow trains to cross from one track to another using a turnout and a series of switches. An interlocking is designed so that it is impossible to give clear signals to trains unless the route to be used is proved to be safe

Apr 06 2013 (11:29)
Blog Post# 715271-4     
S V Iyer*^~   Added by: S V Iyer*^~  Apr 06 2013 (11:29)
Types of Interlocking:

Mechanically operated interlocking:
In mechanical interlocking plants, a locking bed is constructed, consisting of steel bars forming a grid. The levers that operate switches, derails, signals or other appliances are connected to the bars running in one direction. The bars are constructed so that, if the function controlled by a given lever conflicts with that controlled by
another lever, mechanical interference is set up in the cross locking between the two bars, in turn preventing the conflicting lever movement from being made.

Manually operated interlocking:
This is a form of mechanical interlocking as well, but relies on the signalman to move about from one set of points and signals to another carrying with him the keys used to operate them.

Electrically operated interlocking:
In the more advanced electrical or electronic interlocking schemes, the points and signals are worked from one integrated mechanism in a signal cabin which features a display of the entire track layout with indications of sections that are occupied, free, set for reception or dispatch, etc. The interlocking is accomplished not by mechanical devices but by electrical circuitry -- relays and switches in older electrical or electropneumatic systems, and computerized circuits in the newer electronic systems.

Panel Interlocking:
It is a system used in most medium-sized stations on IR. In this, the points and signals are worked by individual switches that control them.

Route Relay Interlocking:
It is the system used in large and busy stations that have to handle high volumes of train movements. In this, an entire route through the station can be selected and all the associated points and signals along the route can be set at once by a switch for receiving, holding, blocking, or dispatching trains.

Source: Wikipedia, IRFCA
Scroll to Top
Scroll to Bottom

Go to Desktop site