BOGIES AND SUSPENSION - South Central Railway

CHAPTER 6 – BOGIES AND SUSPENSION
WAGON MAINTENANCE MANUAL
Page 88 of 121
The part of axles is not to be built except the outside fillet by electric welding.
If the wear on the outer side of the journal is beyond limit, the collar should be built
up by electric welding, and be turned to its original size and shape.
The axle should be checked in workshops for flaws. The axle should be tested
by ultrasonic equipment for flaws and cracks. All axles being used in workshop for
POH stock as well as axles being sent to out-station should be given above tests.
To economize on the consumption of raw material, the BG condemned axles
are being used on MG stock and MG condemned axles on NG stock by forging down,
cutting to required length, heat-treatment and turning. Such axles should also be
subjected to examination and flaw detection. After forging and heat treatment, a test
piece of the material out of the same lot, should be sent to CMT for metallurgical test
to ensure that the material and properties of converted axle are at part with that of the
specified new axles. While converting axle in this manner the journal portions should
be discarded.
i) COTTON WASTE PACKING
Lubrication between the journal and the bearing brass is provided by soaked
cotton waste roll packing. The packing is now being provided in the form of rolls on
standard stock.
A good lubricator should possess following essential qualities:-
It should have adequate oil holding capacity.
It should have good wicking action so as to keep packing up the oil from the
bottom of the axle box.
It should have sufficient resilience so as to maintain a continuous contact with
the journal even on uneven track.
The contact pressure between the journal and the lubricator should be such
that it only maintains a continuous contact with the journal but is not so tight,
as to cause a ‘wiping action’ leading to the suspension of the oil feed to the
fluid oil film.
It should remain, in a specified central position, in the course of normal
service, which is seldom free from repeated impacts of varying intensity.
The structure of the lubricator should be such as will not permit the
detachment of any part of it, which might lodge itself between the journal and
the bearing and thereby obstruct the oil feed.
The cotton waste should normally consist of 40% unteased cop bottoms mixed
with 60% good quality reeling hard waste. The specification had to be relaxed due to
non-availability of the required supplies and the permissible mixture should now
consist of 90% unteased reeling waste. It must, however, be of good white color,
absorbent and elastic. The waste should salso be free from moisture, dust, oily