Rails are fixed to cast iron sleepers using cotters and tie bars. These fittings are described below.
Cotters (Fig. 10.14) are used for fixing tie bars to CI sleepers. Cotters are classified according to their methods of splitting. The four different types of cotters being used on Indian Railways are as follows.
(a) Centre split cotter
(b) Side split cotter
(c) Solid end split cotter
(d) Bent plate cotter
The overall dimensions, taper, etc. of these four cotters are by and large identical; they only differ in their methods of splitting. The length of a cotter is 152 mm and the approximate weight is 0.80 lb per piece.
MS tie bars
MS tie bars are used for holding the two plates of CST-9 sleepers together. The normal length of a tie bar is 2720 mm for BG and 1870 mm for MG. The section of a BG tie bar measures 50 mm x 13 mm and that of an MG tie bar measures 45 mm x 10 mm.