Maintenance and Inspection of Points and Crossing

• Points and crossings require more maintenance effort because of complex assembly and heavy forces applied by rolling stock.

• Manual Maintenance: Covers rectification of clearances, gauge, level &alignment; tightening of fittings; packing.

• Machine Maintenance: By UNIMAT tampers. Alignment, levelling and packing is done. Machine packing is essential for concrete sleeper layouts.

• Reconditioning: Switches and crossings are reconditioned if the wear comes close to permissible limits.

• Ensure efficient drainage.

• Ensure adequate ballast cushion

• Ensure correct spacing of sleepers.

• No junction fish plate at SRJ and HOC. At least one rail should be of the same section.

• Spherical washers are used on skew side. In I.R.S. turnouts with straight switches, these should be provided on the left hand side invariably in the switch assembly.

• Burred stock rail should be replaced.

• Creep anchors and box anchoring of one rail length ahead of stock rail.

• Desirable to weld SRJ and lead curve joints.

• Lubrication of gauge face of tongue rail.

• ST sleepers – Wooden blocks under crossing in case of ST sleepers.

• Gauge Tie Plate should be used on wooden layouts under switch and crossing.

• Tongue rail should bear evenly on all the slide chairs.

• No change of cant outside ATS and HOC for a distance of 20 m on BG and 15 m on MG.

• In case of straight switches, correct amount of bend should be given to the stock rail on the turnout side at the theoretical toe of switch.

• Tongue rail should bear evenly on all the side chair. When the tongue rail is in closed portion, it must bear evenly against distance studs or blocks.

• Insertion or removal of P & C in a running line affecting layout must be carried out only after obtaining sanction of CRS

• Avoid

o Gap at toe

o Loose packing and loose bolts in switch

o Tight gauge at nose of crossing

o Loose bolts in crossing assembly

• If only wing rails are replaced, the difference in the level of nose of Xing and wing rail to be as per original assembly

• On TOs where one road is used predominantly, the wear on Stock Rail should be closely monitored and attended.

• Grind gauge face of stock rail if burr is there.

• Maintain P & C with zero missing fittings.

• In case of bad housing, replace that pair of Stock Rail & Tongue Rail if not able to rectify.

• Cleaning and Lubrication of Points:- At all interlocked and partially interlocked stations the signal staff will be responsible for the periodical cleaning and lubrication of those slide chairs in which signaling and interlocking gears are connected generally upto 3rd sleeper from toe of switch in all points interlocked with signals or provided with locks. The PWI shall be responsible for cleaning and lubrication of slide chairs of all hand operated points on their sections and remaining slide chairs of all points interlocked with signals or provided with locks. (CS.No-103)

SCHEDULE OF INSPECTION OF POINTS AND CROSSINGS

• Regular Inspection by Engineering Officials

      BY ADEN       

• All the points on passenger running lines once in a year.
• 10% of the points on other lines

BY SE (INCHARGE) / JE (NOT IN OVER ALL CHARGE)

• All the points on passenger running lines once in three months by rotation .
• Other points once in six months by rotation.

Sr. DEN/DEN to inspect at his discretion certain number of points particularly on running lines and those recommended for renewal.

Results of Inspections to be recorded in Points & Crossings Register using prescribed Performa.

Joint inspection of P & C

• SE/P.Way (I/C or sectional) and SE/Signal are to jointly inspect all interlocked

points once in three months.

• Mainly switch portion is inspected.

• Results and compliance to be reviewed at Divisional level.

INSPECTION OF POINTS AND CROSSINGS

• Gauge just ahead of ATS

All the turn out with SEA ≤ 0º20’00’’ = Nominal gauge

All the turn out with SEA >0°20’00” = Nominal gauge + 6 mm

Throw of Switch - 115 mm

Gap between top of stretcher bar and bottom of stock rail 1.5mm-3.0 mm

• Maintain prescribed clearance at the heel of switch, at check rail and wing rail

• No loose packing under the crossing and switch.

• All the fittings should be tight and properly secured.

• Badly worn out and damaged tongue rail should be replaced.

• A Tongue rail is classified as badly worn out when :

1. It is chipped /cracked over small lengths aggregating to 200 mm within a distance of 1000 mm from the actual toe of switch.(chipped length will be portion where tongue rail has worn out for a depth of more than 10 mm over a continuous length of 10 mm)

2. Has developed knife edge tip (thickness of top edge being less than 2 mm) over a length of 100 mm anywhere upto a distance of 1000 mm from it’s toe.

3. Badly twisted or bent and does not house properly.

• Tongue rail should be replaced/reconditioned when :

Vert. wear >8 mm (For 60 kg.)

                     >5 mm ( For 52 kg and 90R)

Lateral wear > 8 mm (For 60 kg.)

                         6 mm (For 52 kg and 90R)

• Tongue rails should be replaced/reconditioned when:

1. Vert. wear should be measured at a point where tongue rail head width is 13 mm and where tongue rail and stock rail are at same level.

2. Lateral wear at the above said points 13 to 15 mm below top of stock rails

• Wear on stock rail should not exceed the following limits:

Vert. wear ≤13 mm (for 60 kg.)

                     ≤8 mm ( for 52 kg )

                    ≤5 mm ( for 90R)

Lateral wear : For curve ≤8 mm (For Gr. A & B Routes)

                                           ≤10 mm (For Gr. C&D Routes)

                           For straight     ≤ 6 mm (For Gr. A & B Routes)

                                                   ≤8 mm (For Gr. C&D Routes)

• Max. ver. wear on wing rails or nose of crossing 10 mm

• Max. ver. Wear on wing rails or nose of crossing(for Rajdhani routes)

        Built up/welded 6mm

        CMS 8mm

        For CMS Crossing following should be deducted (to account for slope

           in casting of wing rails to 1 in 20 cant) from measured wear

           2mm for 52 Kg 2.5mm for 60 Kg

• In case of Welded heat treated crossings, the dimensions to be deducted from

the observed wear for finding out actual wear is as shown on the relevant

layout drawing.

Lead potion and turn in curves -

• Initially the lead curve correctness to be ensured by measuring offset from the

straight track

• During maintenance the versine of turn in curve and lead curve should be

measured by 6 m chord at stations at 3 m interval.

• The variation in versine on two successive stations in lead curve and turn in

curve should not be more than 4 mm and at individual stations should not be

beyond ±3mm from it’s designed value.

LUBRICATION OF SLIDE CHAIRS

• By S& T staff for two sleepers of interlocked points

• By Engg. Staff all remaining slide chairs and hand points

• The month and year of laying should be painted by white block letters

1.          On web of tongue rail at 500 mm distance from heel joint
2.          On web of crossing at 500 mm distance from toe