“Ilm-fan muammolari yosh tadqiqotchilar talqinida”
mavzusidagi 9-sonli respublika ilmiy konferensiyasi
22
Rails must be inspected within 10 days to 2 months before they are removed. No
more than 10 days earlier the rails are inspected by ultrasonic and magnetic flaw
detectors and marked directly on the track.
Marking of rails is carried out with light indelible paint on the neck of the rail,
facing inward, at a distance of about 1 m from the left joint and 12.5 m from the end
of the rail strip (when an employee is inside the track facing the marked rail or track
or a track, Fig. 1). In winter period temporary marking with chalk with
subsequent resumption with light indelible paint is allowed.
Fig. 1. Marking place of old-age rails: 1 - left joint; 2 - marking place.
The marking of rails intended for reuse on the track without repair in the RRS
consists of characters on the neck of the rail, defining its suitability group, which is
indicated by the number of vertical lines corresponding to the group number, as well
as the letters A and I for group I-AI, the letter AND for groups I-I, II-I, III-Y, and the
letters T and I for Group III-TI. Thermally hardened Rails are marked with the letter
U, non heat-strengthened - with the letter C (Fig. 1). On rails of I and II suitability
groups type P50 and heavier the missed tonnage (rounded to 10 mln gross tons) shall
be indicated on rails of I and II suitability groups of R50 and heavier.
10 mln tonnes gross) and load intensity of the section (rounded up to 5 mln
tonnes to 5 mln t-km gross/km per year) (Fig. 1, a-c).
Rails removed from curved
sections of track with a radius of 1000 m and less, the letter K should be additionally
indicated (see Fig. 1, c). Rails to be repaired by the RRS before re-laying in the track