This Presentation Contains Railway engineering concepts. The contents covered are Points & crossings: Turnout, switches, throw switches, diamond crossing, cross-overs, single slip and double slip, scissor cross-over, Triangle & turntable. Feel free to write in Comment Section or drop a line in my Inbox amanbathla710@gmail.com
3. Turnout: Definition
Arrangements by which different routes either parallel or
diverging are connected & afford the means for trains to
move from one route to another.
Sometimes turnouts, cross-overs are also used in place of
points & crossing.
4. Turnout: Necessity
The direction of movement & the diversion of the vehicles to
the another track are controlled automatically by wheel
flanges rather than the driver as in case of roads.
Provide flexibility of movement y connecting one line to
another.
Impose restrictions over turnouts to retard the movement.
5. Turnout: Types
The simplest combination of points & crossings which
enables one track to take off from another track.
Depending upon the direction of movements of trains from
main track; turnout are classified as
Left hand turnout
Right hand turnout
6. Left-hand Turnouts
The diversion in which train from the main track is diverted
to the left of the main route in the facing direction.
7. Right-hand Turnouts
The diversion in which train from the main track is diverted
to the right of the main route in the facing direction.
8. Turnout: Working Principle
Turnout works with the combination of Points & crossings.
This consist of mainly a pair of points or switches, Four Lead
Rails, two check Rails & crossing.
Rail track A divides into two: track B (the straight track) and track C
(the diverging track).
the green line represents direction of travel only, the black lines
represent fixed portions of track, and the red lines depict the moving
components
10. Turnout Component: Switch
The pair of linked tapering rails, known as points (switch
rails or point blades), lying between the diverging outer rails
(the stock rails).
11. Switch Component: Points
The points (switch rails or point blades) are the movable rails
which guide the wheels towards either the straight or the
diverging track.
They are tapered on most switches, but on stub switches they
have square ends.
12. Switch Component: Frog
The crossing point of two rails.
Assembled out of several appropriately cut and bent pieces
of rail or can be a single casting of manganese steel.
also known as the common crossing (or V-rail in Australian
terminology).
13. Switch Component: Guard rail
A short piece of rail placed alongside the main (stock) rail
opposite the frog.
Ensure that the wheels follow the appropriate flange way
through the frog and that the train does not derail.
Generally, there are two of these for each frog, one by each
outer rail. Guard rails are not required with a "self-guarding
cast manganese" frog, as the raised parts of the casting serve
the same purpose.
14. Other Switch Components
Stock Rails (The main rails of the track)
Tongue Rails (lie between two stock rails & are tapered to a
point)
Heel Blocks (blocks inserted between the heel of the
tongue rail & stock rail)
Distance Block (block to provide distance between running
rail & check rail)
Stretcher Bar (bar through which the tongue rails are
connected together)
15. Important terms in Switches
Heel Clearance/ Divergence
Distance between the running faces of stock rail & tongue rail
Switch Angle
Angle between running faces of the stock rail & tongue rail
Throw of Switch
Distance through which the toe of the tongue rail moves
sideway
16. Types of switches
1) Stub switch (No separate tongue rail is provided)
2) Split switch (Tongue Rail is combined with the stock rail)
17. Split switch: Types
1) Loose-heel type
2 Front bolts are kept loose
Are not favored
2) Fixed-heel type
Tongue & stock rail kept in position by means of heel or
distance block
Use is limited only long switches
18. Crossing & its requirements
Device to permit vehicles moving along one track to cross the
another track.
Requirements
A side plate should be provided for connecting the point &
splice rails. ( Turned bolts should be used for this
connection)
The foot-flanges of the wing rail should be riveted to the
plate.
Alloy steel for light traffic & high manganese steel should be
used on crossing
Crossing should be rigid.
19. Crossing: Types
1) Acute Crossings or V crossing
Acute angle of intersection
2) Obtuse Crossings or diamond crossing
Obtuse angle of intersection
3) Square Crossings
Tracks are at right angles
20. Important terms in Crossings
Theoretical nose of crossing (T.N.C.)
Sharp imaginary point where the two gauge faces would meet
Actual nose of crossing (A.N.C.)
Point rail is never manufactured to a well defined sharp point
as it would break off under the action of moving traffic
A blunt nose is provided for the point rail.
21. Track Junction
Combinations of points and crossings, with curves &
straights to transfer trains from one track to another
Important track junctions
Three throw switch
Diamond crossing
Cross over
Single & double slip
Triangle
22. Three throw Switch
Two turnouts take off from the same point of a main
line track. A three-throw switch can have contrary
flexure (either side of main track) or similar flexure
(one side of main track)
Contrary Flexture Similar Flexture
23. Diamond Crossing
Straight or curved tracks of same of different gauges
cross each other at angle less than 90 degree