The frogs are made of steel rails; for all common crossings a check rail is placed on each side, at least 12 feet in length, and much longer in special cases. The narrowest part of the throat of the frog is 1¾ inches wide.

From Fig. 22 it will be seen that a common crossing consists of four rails, i.e. one point rail, one splice rail, and two wing rails.

During the study, various railways will be investigating different types of common crossing, such as Vario, manganese steel, glued or bloomed common crossings and common crossings with glued or welded fishplates.

The drawback of these common crossings lies in the difficulty of welding them to the adjacent rails.

Common crossing

Meaning

Noun