7. Transverse Fissures
Fissure or hole in the head occurs due to the poor
manufacturing orexcessive straining.
Poor manufacture,excessive straining
Very Dangerous, railbreaks without any sign
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9. Horizontal Fissures
Horizontal fissures occurs in head and web of
the rail.
Itdevelops and keeps on increasing.
It occurs due to insufficient ballast and worn
fish plates.
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13. Material Required Per Km length of MG
Track
Rails
Length of one rail =12m
Density= 37.2kg/m or(75lb/yd)
No. of rails per km=2*(1000/length of one rail)
=2*(1000/12)=167
Weight of rail per km=(density*length 0f one
rail*no. of rails)
=37.2*12*167=74548.8kg
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14. Sleepers and Fish Plates
No. of sleepers per km=0.5*(no. of rails per
km*(M+X))
=0.5*167*(12+5)=1420
where M=length of one rail
X=density factor
No. of fish plates per Km=2*No. of rails per km
=2*167=334
No. of fish bolts per Km=4*no. of rails per km
=4*167=668
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15. Bearing Plates and Ballast
No. of bearing plates per km=2*No. of sleepers
per km
=2*1420=2840
Bearing Fasteners= No. of sleepers per km*12
=1420*12=17040
Quantity of Ballast=The quantity of ballast
required per m for metre gauge is 0.71cubic
metre.
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16. Different Types of Rail Wear
Wearof rails on the top (vertical wear)
Wear of rails at the end of the rails (battering of the rail
ends)
Wearof rails on the side of head of rail (lateral wear)
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17. Wear of Rails on the Top
The metal from the top of rail flows and forms
projections. These projections are known as
burrs. Rails worn out on the top due to
abrasion of the rolling wheels over them.
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18. Wear of Rails at the End of the Rails
Takes place at the end of the rails. Much
greater than the top of rails. Causes battering
i.e., wear of end. Fish plates become loose.
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20. Wear of Rails on the Side of Head Rails
Most destructive type of wear. Occurs mainly
at the curves.
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21. Method of Measurement of Creep
Creep can be measured with the help of a device called creep
indicator. It consists of two creepposts, which aregenerally rail
pieces that are driven at 1-km intervals on either side of the
track. For the purpose of easy measurement, their top level is
generally at the same level as the rail. Using a chisel, a mark is
made at the side of the bottom flange of the rail on either
side of the track. A fishing string is then stretched between
the two creep posts and the distance between the chisel mark
andthe string istaken asthe amount of creep.
According to the prescribed stipulations, creep should be
measured at intervals of about three months and noted in a
prescribed register, which is to be maintained by the the
permanent way inspector (PWI). Creep in excess of 150 mm (6
in.) should not be permitted on any track and not more than
six consecutive rails should be found jammed in a single-rail
track at one location. There should be no creep in approachesto
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