Passing Loop - Simultaneous Crosses and Passing Lanes

Simultaneous Crosses and Passing Lanes

If a crossing loop is several times the length of the trains using it, and is suitably signalled, then trains proceeding in opposite directions can pass (cross) each other without having to stop or even slow down. This greatly reduces the time lost by the first train to arrive at the crossing loop for the opposing train to go by. This system is also referred to as a dynamic loop.

In the AusLink project for the Junee to Melbourne line, roughly every other section of single line will be duplicated to provide so-called passing lanes. About 220 km of the 450 km line will be duplicated.

In Sweden, the passing loops are generally 750 m long, made for cargo trains. Passenger trains are usually much shorter, at least on most single track lines, less than 200 m. The signalling system now allows two passenger trains to cross without stopping, but one has to slow down to 40 km/h, because of the limited length of the loop and the sharp curves in the switch points.

For Norway an investigation has been made about future high speed railways, using 250 km/h as cruise speed. The most promising link would be a new Oslo-Trondheim railway, which is suggested to be single track along a 370 km long route. It is suggested to have about 15 km long passing loops, more like 15 km double track, located about 80 km apart. This would enable passing in 160 km/h, but there could be only one train per hour per direction on the rail line. See also High-speed rail in Norway.