The ideal rail joint is one that provides the same strength and stiffness as the parent rail. The characteristics of an ideal rail joint are briefly summarized here.
Holding the rail ends An ideal rail joint should hold both the rail ends in their precise location in the horizontal as well as the vertical planes to provide as much continuity in the track as possible. This helps in avoiding wheel jumping or the deviation of the wheel from its normal path of movement.
Strength An ideal rail joint should have the same strength and stiffness as the parent rails it joins.
Expansion gap The joint should provide an adequate expansion gap for the free expansion and contraction of rails caused by changes in temperature.
Flexibility An ideal rail joint should provide flexibility for the easy replacement of rails, whenever required.
Provision for wear An ideal rail joint should provide for the wear of the rail ends, which is likely to occur under normal operating conditions.
Elasticity An ideal rail joint should provide adequate elasticity as well as resistance to longitudinal forces so as to ensure a trouble-free track.
Cost The initial as well as maintenance costs of an ideal rail joint should be minimal.