Gauntlet track

Gauntlet track or interlaced track (also gantlet track) is an arrangement in which railway tracks run parallel on a single track bed and are interlaced (i.e., overlapped) such that only one pair of rails may be used at a time. Since this requires only slightly more width than a single track, all rails can be carried on the same crossties/sleepers. Trains run on the discrete pair of rails appropriate to their direction, track gauge or loading gauge.

The term gauntlet is derived not from gauntlet meaning a type of glove, but from the expression running the gauntlet (originally running the gantlope) which means running between two confining rows of adversaries; gauntlet in this sense is a "corrupt form".

Gauntlet tracks can be used to provide horizontal clearance to a fixed obstruction adjacent to a track such as a cutting, bridge, or tunnel. Frog gauntlets are also commonly used when a rail line's capacity is increased by the provision of an additional track, but cost or other factors prevent the widening of the bridges. They are typically used for short stretches of track where it is cheaper to provide extra rails than to provide switches and reduce the line to single track. This also eliminates the problem of switch failures.

In a frog gauntlet, one rail crosses over a rail on the adjacent track. A frog is used to provide the flangeway for the crossing tracks. The train taking the gauntlet runs over the frog onto the parallel rails, passes through the gauntlet area, and passes over another frog to return to the original line. Since there are no points or other moving parts on a frog gauntlet track, a train operating on one of the tracks cannot be routed onto the other.

Because two trains cannot use the gauntlet at the same time, scheduling and signalling must allow for this restriction.

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