Special types of crossing

Diamond crossings

When one track crosses an other at an angle, a diamonds is formed comprising of two acute and two obtuse crossings. When a vehicle passes over a diamond crossing, there is an inherent risk of derailment owing to a large unguided gap at the elbow of the obtuse crossing and due to the possibility of a wheel, particularly of a small diameter, being deflected to the wrong side of the nose. The position becomes worse, when the angle of intersection is very acute. In the Indian Railways, it has therefore been laid down that diamond crossing normally should not be flatter and less acute then 1 in 8 ½.

Diamond crossings

Square Crossing

When two tracks cross one another at right angles, a square crossing is formed. Square crossings are generally avoided, since the gap in the running rail for wheel flanges, being opposite to each other, causes severe jolting to vehicles resulting in the rapid wear of the crossings and damage to rolling stock on account of the heavy impact.

Square Crossing

Moveable Switch Diamond

Movable switch diamonds are used for flatter crossing angles i.e. 1 in 10 or 1 in 12, where normal crossing is not permitted as mentioned in

Diamond Crossings with slips

If track are to be so arranged that a train on one track may normally cross another track, but when required, may also be diverted to that track, an arrangement known as diamond crossing with slips is installed. This is made possible by the inclusion of two or four pairs of switches, with the connecting lead rails. When such diversion is permitted in one way the arrangement is known as single slips, and if it is permitted in both ways, the arrangement is known as double slip.

Diamond Crossings with slips

Scissors Crossover

When two crossover overlap exactly opposite to each other, a scissors cross over is formed. It consists of 4 turnouts and diamond crossing. The same function can be performed by two crossovers following one after the other, but the advantage in scissors crossover is the saving of space. This is commonly used in busy passenger yards when two train are dealt with on a single long platform.

Scissors Crossover

Triangles turnout

Triangles are laid for turning engines, or vehicles end to end in place of turn tables. They are laid when space is available. Their maintenance cost is very little as compare to turn tables. It consists of two 1 in 8½ turnouts, one 1 in 8½ symmetrical split with connecting rail.

Triangles turnout

Gathering lines

A gathering line or a ladder track is one into which a number of parallel track merge. This layout is commonly used in goods yard.

Gathering lines

Gauntleted Track

It is an arrangement in which two track of the same or different gauges are carried together for a certain length. The arrangement is useful, when both BG and MG track is to be carried together on the same bridge. Gauntlet track has two crossings of the same gauge or mixed gauge, at either ends, without any switches.

Gauntleted Track