| bolted rail crossing | A crossing in which all running surfaces are of rolled rail and the parts are held together with bolts. |
| manganese steel insert crossing | A crossing in which a manganese casting is inserted into the intersections, fitting into the rolled rails and forming the points and wings of the crossing frogs. |
| solid manganese steel crossing | A crossing in which the frogs consist entirely of manganese steel castings. |
| center frogs | The two frogs at opposite ends of the short diagonal of a crossing. |
| end frogs | The two frogs at opposite ends of the long diagonal of a crossing. |
| running rail | The rail or surface on which the tread of the wheel bears. |
| guard rail | The rail placed parallel with the running rail with the flangeway between them. |
| easer rail (easer) | A rail placed with its head along the outside and close up to the head of the running rail and sloped at the ends to provide a bearing for the overhanging portion of hollowed-out treads of worn wheels. |
| single rail crossing | A crossing in which the connection between the end frogs and center frogs consist of running rails only. |
| two-rail crossing | A crossing in which the connection between end frogs and center frogs comprises running rails and guard rails. |
| three-rail crossing | A crossing in which the connection between end frogs and center frogs comprises running rails, guard rails and easer rails. |
| movable point crossing | A crossing in which each of the two center frogs is formed of a obtuse point or knuckle rail and two opposed movable tapered rails, with operating mechanism connecting them so that when two of the movable rails lie against the point or knuckle rails, giving a continuous running surface on one track, the other two stand away from the point to give clearance for the wheel flanges to pass. (Used in small angle crossings and slip switches.) |
| knuckle rail | A bent rail forming the obtuse point against which the movable rails operate in a movable point crossing. |
| reinforcing rail | A piece of rail placed along the outside of the head of the knuckle rail or movable center point for strengthening and to act as an easer rail. |