Prohibited Locations for LWR
Due to the technical problems
arising on account of the use of long welded rails, the Indian Railways have
specified locations where the laying of LWRs is prohibited. These locations are
constructions and doublings of lines, where the formation and the track is not
fully stabilized. However, if mechanical compaction of the earthwork is done,
LWRs may be laid on the new lines at the initial stage itself with the approval
of the chief engineer.
where rails are subjected to heavy wear, corrugation, or corrosion, or require
where the formation is weak and track deformations are extensive, which may
lead to buckling.
where the formation soil is susceptible to pumping and the ballast is likely to
get heavily contaminated, thereby necessitating the frequent opening of the
track and the screening of the ballast.
where frequent breaches, flooding, and subsidence may occur.
(f) On curves
with a radius sharper than 500 m. In the case of reverse curves, the limiting
value is 1500 m.
steepest gradient permitted for LWRs is 1 in 100. At every change of gradient,
vertical curves should have the minimum radii listed in Table 17.1.
17.1 Minimum radii for
vertical curves at gradient changes
All other locations besides those
listed in Table 17.1 are known as permitted locations for LWRs.