BOGIES AND SUSPENSION - South Central Railway

CHAPTER 6 – BOGIES AND SUSPENSION
WAGON MAINTENANCE MANUAL
Page 37 of 121
It is a hollow casting forming a box section for about 2/3 of its middle
length and ‘C’ section for 1/3 of its length at the ends. Its ends sit on the
spring nest through the spring plate. In the centre and on its top surface,
bottom centre pivot is fixed with four counter-sunk rivets. Bottom side-bearers
are fitted on its top surface at both the ends, each secured with the bolster by
two bolts. Similarly bogie top centre pivot and top side-bearers are fitted in
corresponding positions on the underframe of the wagons. The portion of the
bolster, where centre pivot is fitted, is rough machined and the portions
coming in contact with side- bearers are finish-machined. There are four holes
in the bolster to rivet the bottom centre pivot and two holes on both ends to
bolt the bottom side-bearers with it. Also, at each end, there are two blind
holes to receive the nibbed portion of the spring plate. In the centre, an
opening is left in the casting to receive the centre pivot pin. The pin goes to
about half the depth of the casting.
In the central portion on both the sides, at about half the depth of the
casting, four holes have been provided to fit the bogie brake fulcrum bracket
with the bolster. One fulcrum bracket is fitted on the bolster towards the buffer
end.
d) BOGIE CENTRE PIVOT (BOTTOM)
It is fitted on the top of the floating bolster, exactly in the centre,
secured with the latter by means of four counter-sunk rivets. It is finish
machined all round at all places except on the four vertical edges of the
rectangular flange. There is a central hole to allow the fitment of bogie centre
pin through it. The initial diametrical clearance between the hole and the pin is
2 mm. The top surface of the bottom pivot is in concave spherical shape
(Radius: MG-710 mm, BG-495 mm). The corresponding convex spherical
surface of the top pivot of equal radius rests on it. The vertical central pin like
portion of the bottom pivot goes inside the corresponding hollow portion of
the top pivot. The side surface of the pin portion is in convex spherical shape
(Radius: MG - 115 mm, BG - 225 mm). There are circular grease grooves on
the concave & convex surfaces of the bottom and top pivot respectively. The
vertical inner edge of the bottom pivot has slight radius at the top. There are
four rivet holes near the corners of the rectangular flange.
e) BOGIE SIDE BEARERS (TOP & BOTTOM)
Side bearers are provided on the wagons to limit the rolling movement.
Two bottom side bearers are fitted on the bogie bolster, one at
each end. Similarly two top side-bearers are fitted in corresponding position
on the underframe. The bottom side-bearers are made of cast iron. Its cross
section is like a box section with one side having a flange. Its longer edge is
curved. It has a long rectangular hole in which oil soaked cotton waste is
provided for lubricating the rubbing surfaces. The flanged side has two bolt
holes to bolt it with the bogie bolster. Its top and bottom surfaces are finish
machined.