BOGIES AND SUSPENSION - South Central Railway

CHAPTER 6 – BOGIES AND SUSPENSION
Don’ts
WAGON MAINTENANCE MANUAL
Page 96 of 121
(v) Ensure use of journal gauges to measure the length and diameter of the
journal and the suspension link for sounding the brass.
(vi) Ensure that an arc of contact of 30 o is provided on the bearing brass.
(vii) Ensure that a minimum of 3 mm for MG and 5 mm for BG lateral play
is provided between the brass and the journal.
(viii) Ensure that oil is measured on the journal, bearing brass and the two
sides of the key plate before assembling the axle.
(ix) Ensure that the key plate is sitting properly in relation to the bearing
brass lug and the axle box retaining lug.
(x) Ensure that packing is carried in drums fitted with lids.
(i) Do not re-use a bearing brass with spread white metal on sides without
it being redressed and restored to an arc of contact of 30 o on the crown.
(ii) Do not use baffle block (wooden keep) of non-standard size.
(iii) Do not pack the axle box in a manner, which may permit the roll
packing to come beyond the inner edge of the journal collar.
605 S. WHITE METALLING PROCEDURE
The carriage and wagon bronze bearing shell should be tinned and white
metalled with antifriction metal strictly according to the practice laid down in the
subsequent paragraphs. As regards SGCI shells, the procedure prescribed in the
pamphlet “Prevention of Hot Boxes - A Guide” revision 1, issued by RDSO should be
followed.
De-metal the old bearing in a de-metalling bath. The temperature of the demetalling
bath should be kept 400 o C and 450 o C. The bath should be an oil fired, pot
type furnace with temperature controlling and recording devices.
In this operation, the white metal lining is melted and collected in the bath and
all the oil is normally burnt. The white metal collected in the demetalling bath should
be ingoted and reconditioned.
Remove the shell from the demetalling bath soon after the white metal has
been melted and clean it by scrubbing with a stiff wire brush to remove traces of dross
and other impurities. The shell should then be allowed to cool in air.
Check the demetalled shell with suitable gauges for important dimensions
such as overall length, width at the ends, crown depth, and the height and length of
the lug. The maximum wear of 2 mm may be permitted on the length and width of
the brass as also on the length and height of the lug. Maximum permissible wear on
the crown depth is 6 mm in B.G and 3 mm in M.G. Shells. Any demetalled shell,
worn beyond these limits should be rejected and sent to the foundry for being recast.