interchanging of rails a.gunashekar aden.bpq nagpur division central railway 1

INTERCHANGING OF RAILS

A.Gunashekar ADEN .BPQ NAGPUR Division

CENTRAL RAILWAY

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Cause of Lateral wear

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• HOW TO INTERCHANGE IN STRAIGHT

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We can not bodily lift the rail one by one and Shift from Left to Right

• HOW TO INTERCHANGE IN STRAIGHT

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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

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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

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How the panel is moving in the direction of Interchange (Straight)

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500m

500m

When shifting from LH to RH,

How to Interchange (Straight)

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500m

500m

How to Interchange (Straight)

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500m

500m

Length required to form reverse curve is pulled in the direction of work

How to Interchange (Straight)

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500m

500m

How to Interchange (Straight)

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500m

500m

How to Interchange (Straight)

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500m

500m

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

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Snakinglength

Other side panel is slewed over the first to otherside

It has moved ‘s’ distance to the right side

s

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‘s’ distance is carried to the right side

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ss

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

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Sameway the other panel has also moved to the right

Two extra rails are to be replacedFour extra cuts are to be provided

s

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Snaking length s =60mm

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500 m

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

60mm 60mm

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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

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Other side panel is slewed over the first to otherside

It has moved ‘s’ distance to the right side

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‘s’ distance is carried to the right side

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‘s’ distance is carried to the right side

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ss

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

No extra rail replacement & no extra cut is involved

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200 m

200 m

LG/R

Interchanging of panels in curve

Para.424 IRPWM Outer length of Railis longer than inner Rail by LG/R

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LG/R increasing against the direction of progress

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How to start interchange in CURVE

We can not bodily lift the rail one by one and Shift from Left to RightLike in this animation

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How to start interchange in CURVE

200 m

200 m

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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

200 m

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Inside panel is slewed outside from LH to RH

200 m

200 m

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200 m

200 m

LG/R

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200 m

200 m

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LG/R

200 m

200 m

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200 m

200 m

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LG/R

200 m

200 m

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200 m

200 m

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200 m

200 m

Sameway the other panel has also moved to the right

Four extra rails are to be replacedFour extra cuts are to be provided

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LG/R

LG/R + La T - S

L T - S

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Marking of cut locations at starting

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200 m

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.

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200 m

200 m

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

200 m

200 m

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Inside panel is slewed Outside from LH to RH

200 m

200 m

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200 m

200 m

No extra rail replacement & no extra cut is involved

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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)

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Clueless Interchanging andBursting of Block

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Clueless Interchanging andBursting 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.

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Snaking length s =21.6mm

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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)

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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

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d =La T

Rail Length Coeff.of expansion

Temp Variation

Change in Length

52Kg 100m 1.152X10-5 100 C 11.5mm 60Kg 100m 1.152X10-5 100 C 11.5mm

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D =Lat

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.

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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

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300 m

280 m

LG/R

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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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