I. General

1. Spacing of tracks :

  1. Minimum distance centre to centre tracks



  1. Curves

Minimum radius of curves



  1. Rails :
  1. Minimum clearance of check rails for a curve:



  1. (a) Minimum clearance of check rail at a level crossing.
  2. (b) Maximum clearance of check rail at a level crossing.


57 mm

51 mm


  1. Tunnels, through and semi-through girder bridges :

Minimum distance centre to centre of tracks


4725 mm



  1. Safety refuges : Maximum distance apart of refuges in tunnels

100 m

100 m

  1. Maximum distance apart of trolley refuges :



  1. On bridges with main spans of less than 100 m.
  1. m
  1. m
  1. On bridges with main spans of 100 m or more

A refuge over each pier

A refuge over each pier

  1. Station yards :Maximum gradient in station yards unless special safety devices are adopted and/or special rules enforced to prevent accidents in accordance with approved special instructions.


1 in 400


1 in 400

  1. Platforms :Horizontal distance from centre of track to face of platform coping

1680 mm Maximum 1670 mm minimum

1345 mm

(ii) Horizontal distance from centre of track to face of any platform wall

1905 mm maximum 1675 mm minimum

1345 mm

  1. Height above rail level for high passenger platforms

840 mm maximum 760 mm minimum

405 mm of any passenger platform, 305 mm minimum

  1. Maximum height above rail level for low  passenger platforms

455 mm

  1. Maximum height above rail level for goods platforms (except horse and end loading platforms)

1065 mm

685 mm

  1. Points and crossings :
  1. Maximum clearance of check rail opposite nose of crossing

48 mm

44 mm

  1. Minimum clearance of check rail opposite nose of crossing and at heel of switch rail

44 mm

41 mm

  1. Maximum clearance of wing rail at nose of crossing

48 mm

44 mm

  1. Minimum clearance of wing rail at nose of crossing

44 mm

41 mm

  1. Minimum clearance between toe of open switch and stock rail

95 mm

89 mm

  1. Minimum radius or curvature for slip points, turnouts or cross over roads,

218 m

116 m

II. Electric traction.

  1. Direct current :

Minimum distance between live conductor wire and any structure

130 mm

152 mm

** Note: In case of 1 in 81/2 diamond crossing the minimum clearance between nose and check rail/check flat obtuse crossing shall be 38 mm.  
 Broad Gauge 1676mm

  1. Standard track structure on trunk routes: 60 Kg UTS Rails, 60Kg PRC Sleepers at 1660 Nos per km, Ballast cushion below sleeper 350mm, formation width 7.85m with 1 in 40 cross slope. Rails are seated over 6/10mm GRPs on PRC sleepers fixed with Liner and ERCs. Design speed 160kmph. At present max speed is 130 Kmph and on certain sections, with enhanced safety standards few trains run at 160 Kmph.
  2.  Rails of 13/26m long are being manufactured and laid in track. Certain gap (up to 6mm) to be provided towards thermal expansion /contraction. Since these rail joints necessitate regular maintenance, speed is restricted, generation of heavy sound while passing the joint, the rail joints are welded to form Long/continuous welded rail (LWR/CWR). The thermal forces are countered by increased track resistance by way of heavier rail /sleepers, ballast cushion, modern type fittings (GRPs, Liners, ERCs) and SEJs at the end of LWR/CWR
  3. Points & Crossings are provided in station yards for moving from one line to another line. Generally, 1 in 8½, 1 in 12 and 1 in 16 point’s crossings are adopted on Indian Railways. Present Speed potential on these points is from 10 Kmph to 30 Kmph and 50 Kmph with improved design.
  4. Maximum degree of curved track is 10o on B.G. and maximum Super elevation (cant) is 165mm.
  5. Spacing of railway tracks is 5300mm between track centers and it will be increased by width of post /stanchion /structure if any, existing between tracks.
  6. Safety Zone is 15m in cities/urban area and 30m in other areas from railway track and no structures above/below ground level is permitted in safety zone. No objection from Railway is to be obtained for any construction proposed to be undertaken within 30 m from Railway boundary and the local civil authorities to ensure the same.
  7. USFD (Ultrasonic Flaw detection) testing of track is carried out at periodicity based on the traffic density to detect any flaw propagation in rail section and to take measures to avoid unusual.
  8. Spacing of tracks in station yard /section in electrified areas is 5300mm.
  9.  Height of platform surface is 840mm from rail top and edge of platform is at 1670 -1680mm from Centre of track.
  10. Height of any overhead structure crossing railway track with electrification shall be 6250mm from rail level to bottom of overhead structure (Road over Bridge / Foot over Bridge)
  11. Minimum width & height of any structure underneath track to pass drain, pipe line etc., is 1.2m.
  12. Height Gauge provided on road approaches of Level Crossing with clearance of 4.67m. Similarly, on road approach of any RUB the clearance available for road vehicle will be 150mm less than actual clearance in RUB to prevent road vehicles touching/damaging RUB superstructure.
  13. Vertical clearance to be maintained between rail level to bottom of ROB superstructure (girder/ slab) is 5870 / 6250mm for heavy/light overhead structure. (It shall be 8050 / 8430 mm for electrified routes of double stack container plying).
  14. Minimum horizontal distance of structures of HT power line crossings from Centre of nearest track shall (Height of such structure+6) m. Upto 32 KV power lines crossing overhead is not permitted and it shall be through cables passing through Pipes of 915mm dia or more underneath track.
  15. Minimum size of any bridge underneath track shall have 1.2mx1.2m clear opening.

UTS – Ultimate Tensile Strength; PRC – Pre-stressed reinforced concrete sleepers; GRP – Grooved Rubber Pad; ERC – Elastic Rail Clip; ROB/RUB – Road Over/Under Bridge; 60 Kg rail – unit weight rail is approx. 60 kg per meter length