Double junction

The simplest and oldest arrangement consists of two turnouts (points) and a fixed Diamond crossing.

Because the diamond needs to be relatively coarse, say 1 in 8, the curve radius is necessarily small, leading to a speed of perhaps 25 km/h (16 mph).

The additional ends are also awkward to control unless power operated point machines are used.

Examples include Harris Park railway station, Sydney.

A single lead junction is used where traffic density is lower, and moves one of the turnouts on the main line onto the branch.

However, unlike in the ladder, branch trains in opposite directions can collide head-on at 32 if either one passes a signal at danger (SPAD).

This has contributed to fatal accidents, e.g. in the UK at: Glasgow Bellgrove on 6 March 1989 and Newton on 21 July 1991.

If the legs of the coarse crossing X are straight and flat, then this arrangement eliminates the need for switched diamonds and their inconvenient moving parts.

The Channel Tunnel has at its entrances a scissors crossover implemented with two turnouts replacing the usual diamond crossing in the middle.