INTERCHANGING OF RAILS A.Gunashekar ADEN.BPQ NAGPUR Division CENTRAL RAILWAY 1

Cause of Lateral wear 2

HOW TO INTERCHANGE IN STRAIGHT 3 We can not bodily lift the rail one by one and Shift from Left to Right

HOW TO INTERCHANGE IN STRAIGHT 4 We can not bodily lift the rail one by one and Shift from Left to Right

200 m Equal length of 200 m is cut squarely opposite 5

One panel is slewed to the centre of track from LH side to RH It has slightly shifted to the right side IN THE DIRECTION OF WORK 6

How the panel is moving in the direction of Interchange (Straight) 7 500m When shifting from LH to RH,

How to Interchange (Straight) 8 500m

How to Interchange (Straight) 9 500m Length required to form reverse curve is pulled in the direction of work

How to Interchange (Straight) m

How to Interchange (Straight) m

How to Interchange (Straight) m And the panel has crept to Right side

One panel is slewed to the centre of track from LH side to RH It has slightly shifted to the right side IN THE DIRECTION OF WORK 13

Snaking length Other side panel is slewed over the first to otherside It has moved ‘s’ distance to the right side s 14

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‘s’ distance is carried to the right side 18

s s After interchanging the panel has moved in the direction of work ‘s’ distance 19

Sameway the other panel has also moved to the right Two extra rails are to be replaced Four extra cuts are to be provided s 20

Snaking length s =60mm 21

500 m Equal length of 500 m is cut out of square by 60mm opposite 60mm 22

One panel is slewed to the centre of track from RH side to LH It has slightly shifted to the left side IN THE DIRECTION OF WORK 23

Other side panel is slewed over the first to otherside It has moved ‘s’ distance to the right side 24

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‘s’ distance is carried to the right side 27

‘s’ distance is carried to the right side 28

s s After interchanging the panel has moved in the direction of work ‘s’ distance No extra rail replacement & no extra cut is involved 29

200 m LG/R Interchanging of panels in curve Para.424 IRPWM Outer length of Rail is longer than inner Rail by LG/R 30

Para 424 IRPWM The excess length ‘d’ by which the inner rail gains over the outer rail is; d = LG/R Sl.NoDegree of curve Length of Interchang planned d' in mm m200mm m300mm m400mm m500mm m600mm m700mm m800mm m900mm m1000mm m1100mm m1200mm

LG/R increasing against the direction of progress 32

33 How to start interchange in CURVE We can not bodily lift the rail one by one and Shift from Left to Right Like in this animation

34 How to start interchange in CURVE

200 m 35 Outside panel is slewed to CENTRE OF TRACK. from LH to RH LG/R gap is left at LH and LG/R extended at RH

200 m 36 Inside panel is slewed outside from LH to RH

200 m 37

200 m LG/R 38

200 m 39 LG/R

200 m 40

200 m 41 LG/R

200 m 42

200 m 43

200 m Sameway the other panel has also moved to the right Four extra rails are to be replaced Four extra cuts are to be provided 44 LG/R

LG/R + L a T - S 45

Marking of cut locations at starting 46

200 m LG/R Equal length of 200 m is cut out of square by LG/R. To your surprise Far end cuts will become square. 47

200 m 48 Outside panel is slewed to CENTRE OF TRACK. from LH to RH

200 m 49 Inside panel is slewed Outside from LH to RH

200 m 50

200 m No extra rail replacement & no extra cut is involved 51

Criteria for Interchanging On Curve when lateral wear exceeds 8mm On Straight when cyclic wear exceeds 6mm On Straight when half service life of rail has passed Corrosion prone area where rail flange corrosion under liner’s seat is predominant on inside. Conversion of SWR in to LWR (also in Tunnels). Conversion of 3 rail panel into 20 rail panel in Ghat (Under trial to avoid excessive creep) 52

Clueless Interchanging and Bursting of Block 53

Clueless Interchanging and Bursting of Block Without PLANNING,if the Interchanging is carried out by deploying labours at both ends, the rail will buckle as it reaches the centre of panel, as shown in figure. First keep the Outer rail at middle of track, then the Inner rail to outside of curve. 54

Snaking length s =21.6mm 55

Different Locations 1. On Curves (In SWR) a) With Square Joints b) With Mid Staggered (Sharp Curves) 2. On Straight (LWR) 3. On Curve (LWR) 56

FACTORS AFFECTING THE LENGTH 1. LG/R increasing against the direction of progress 2. Snaking effect in the direction of progress 3.L T against the direction of progress 4. Welding Gap 57

Para 424 IRPWM The excess length ‘d’ by which the inner rail gains over the outer rail is; d = LG/R Sl.NoDegree of curve Length of Interchang planned d' in mm m200mm m300mm m400mm m500mm m600mm m700mm m800mm m900mm m1000mm m1100mm m1200mm

Para 424 IRPWM The excess length ‘d’ by which the inner rail gains over the outer rail is; d = LG/R Sl.NoDegree of curve Length of Interchang planned d' in mm m200mm m300mm m400mm m500mm m600mm m700mm m800mm m900mm m1000mm m1100mm m1200mm

60 D =L a t

Consider 1 Km track with reverse curves of 300 m long each and 400m straight 1. The 300m of I st curve got to be Inter changed due to excessive side wear in LH rail 2. The 300m of II nd curve got to be Inter changed due to excessive side wear in RH rail 3.In the second Interchanging the 300m of I st curve got to be Inter changed due to excessive side wear in LH rail, for which I st or II nd class rails shall be arranged. 4.The released panel of the above shall be dollied to II nd curve and the second Interchanging shall be done 5. The released panel of the above shall be dollied to straight portion of the track and replaced.And the released rail can be kept reserved for future Interchanging. 61

Advantages Safety 1.Rail profile can be controlled and monitored 2. GFC defects are avoided from propagation. Economy 3. Number of welded joints are reduced 4.Optimum use of rail 62

300 m 280 m LG/R 63 At the mid of curve make two cuts on inner and outer rails in perfect square with each other Measure equal distance,up to where the rail is worn and got to be Interchanged on both rails and make cuts on both rails. 300 m 280 m Keep the outer rail at the centre of track starting from LH end Take the inner rail to the outer side over the rail at centre of track from LH end Shift rail at the centre of track to the inner side from LH end Same way the RH side of curve is Interchanged from RH end NO CALCULATION AND NO THEORY Follow the steps below to Interchange any curve without closure rails

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