BOGIES AND SUSPENSION - South Central Railway

CHAPTER 6 – BOGIES AND SUSPENSION
603 C. MAINTENANCE OF SUBASSEMBLIES
a) MAINTENANCE OF CAST STEEL SIDE FRAME
WAGON MAINTENANCE MANUAL
Page 40 of 121
It is very important that the axle box holes are drilled at correct
distance from the centre of the casting. Also centre distance of the holes meant
for the same axle box should be correct. Holes meant for riveting the spring
plank should be correctly located and marked in the side frame as well as in
the spring plank otherwise this will not give correct bogie alignment. After
and before riveting, the holes alignment should be checked and corrected, if
necessary. Similarly, after assembly of the tie bar, its alignment should be
checked before final riveting it with the casting. For alignment, it is necessary
to check whether the axle box bolt holes in the side frame & tie bar are in the
same line and top and bottom holes are in alignment with each other. It should
also ensured that tie bar is horizontal & parallel to the top surface and at
correct distance from the top surface. The longitudinal edges of the tie bar
should also be parallel to the top edge of the side frame otherwise, box will
not fit properly.
At the time of POH as well as in sick line, side frame should be
examined for cracks, distortion, excessive pitting etc. During POH,
longitudinal, transverse and diagonal distances of the journal centres should be
checked to ascertain the squareness and correct alignment of the trolley. The
permissible variation is 3 mm in longitudinal and diagonal distances, and 2
mm in transverse distances. If the variation extends beyond these limits, the
defects should be rectified.
During POH the central distance of axle box holes and the diameter
should be checked. Normally wear takes place in the hole. However the holes
should be built up by welding & drilled to correct distance, when the dia
exceeds by 2 mm above the nominal size. The steel bushes in the bracket of
the brake beam hanger should be checked for wear and replaced when dia
exceeds 0.75 mm above the nominal size. The rivets of the spring plank and
tie bar should be checked for soundness. It should be replaced if found
unsound. The alignment of the tie bar with corresponding top surface and side
frame should be checked If found defective, it should be rectified.
There is one drain hole in each of the top extended portion and two in
bottom central portion of the side frame. During POH and in service, these
holes should be cleaned and kept clear.
b) MAINTENANCE OF SPRING PLANK
It is important that the holes meant to secure the Cast Steel frame and
Diamond frame bogies respectively are drilled correctly to ensure squareness
and proper alignment of the trolley. Before finally riveting the squareness and
alignment should be checked. In service, the spring plank is prone to corrosion
and excessive pitting. The extent of pitting should be assessed at the time of
POH. If necessary, the spring plank should be replaced.