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".
Triple gauntlet track at Kaufungen, Germany. Wider mainline trains go down the centre; narrower trams switch either to the left, or right, to be closer to the relevant platform. Beyond the station, the rails return to single track.
Where two tracks converge into gauntlet track, they overlap rather than connect.
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.
Point gauntlet/interlaced loop (single-gauntlet-single)
In a point gauntlet track, the rails for the two tracks do not need to cross, so no frog is required. The train taking the gauntlet runs over a set of switch points onto the parallel rails, passes through the gauntlet area, and passes over another set of switch points to return to the original line. This arrangement is used at the Roselle Park Station referenced below.
Interlaced loop with sprung catch point
At a small number of locations on single track lines in Britain, interlaced loops had been provided where sprung catch points were required because of the steep gradient. The points at either end of the loop were set according to the train's direction of travel. Trains running uphill were routed via the loop incorporating the sprung catch point. Trains running downhill used the opposite loop, bypassing the catch point.
Where tracks diverge, a section of gauntlet track may be provided where the switches require to be located remote from the actual divergence. This arrangement is most commonly used on tram systems, to move the switches away from a heavily trafficked road.
An arrangement similar to gauntlet track is sometimes used to allow trains of different gauges to use the same track. In that case, the two interlaced tracks will have different gauges, sometimes sharing one of the rails for a total of three rails.
In Sydney, the Como bridge over the Georges River between Oatley and Como was built as single line in the 1880s. The line was duplicated soon after, except for that bridge. The bridge was fitted with gauntlet track, which needs no turnouts, and hence needs no signal box at the far end. The bridge was replaced with a double-track bridge in 1972.
Another example is visible in the tunnel under George Street, Railway Square, as part of the spur which leads from the connection between Redfern and the Darling Harbour goods station. This was a two-track tunnel (one of the oldest on the New South Wales railways) but became gauntlet track when the line was electrified to allow electric locomotive-hauled freight trains to access the former Darling Harbour. There was insufficient clearance in the tunnel to install overhead catenary above both tracks. A single track now continues on to the PowerHouse Museum and can be visited as part of the Ultimo Pedestrian Network. This track formerly served the Darling Harbour goods yards and was disconnected from the rest of the corridor which now forms part of the Sydney Light Rail network.
At a number of places, including Campsie, a low-speed weighbridge was installed on some gauntlet track, with a high-speed route being available for trains not needing weighing on the other track.
Gemmenich Tunnel and the route taken by wide loads passing through it
The Gemmenich Tunnel (German: Gemmenicher Tunnel, French: Tunnel de Botzelaer) passing under the Dreiländerpunkt (Three country point) has a special track layout to enable the passage of wide military loads. The double-track tunnel has a third set of rails interlaced with one of the normal tracks. Active points (switches) at each end of the tunnel allow a train to divert along the central track, whilst other trains are blocked by signalling. The third track is rarely in use, so there is no limitation of capacity through the tunnel for standard-sized trains.
Close to where the borders of Belgium, Germany and the Netherlands come together, the interlaced tunnel section provides an important connection between Germany and the Belgian harbour at Antwerp. After completing the installation in 1991, trains with an oversize loading gauge were rerouted over this line, and the lightly used (but tunnel-free) secondary line between Stolberg and Welkenraedt (crossing the border at Raeren) was closed to freight traffic. Trains requiring use of the central track must be diesel hauled as electrification only currently reaches the tunnel mouth on the German side to allow for banking.
The Charleroi Pre-metro's Metro sections are entirely double-track, save for a short section along the Route de Mons, where a rail bridge abutment should have been moved to facilitate double track of premetro passing under it. Instead, a short section of gauntlet track is used. Behind the Anderlues depot of the Charleroi pre-metro there is an old-section of dual-gauge track, having both 1,000 mm (3 ft 33⁄8 in) metre gauge (tram/metro) and 1,435 mm (4 ft 81⁄2 in) standard gauge.This section is no longer used by tram nor rail.
The Toronto Streetcar System includes a very short section of gauntlet track on Queen Street East, at Coxwell Avenue.  (Google Street View image) A loop allowing southbound cars to return northbound on Coxwell Avenue briefly interlaces with the westbound track on Queen Street, due to turning radius limitations. A switch partially within the gauntlet section allows westbound streetcars from Queen Street to transition to the loop curve, and turn right onto Coxwell Avenue, but streetcars already within the loop cannot switch to the westbound Queen Street track.
On tram networks, gauntlet tracks are used to pass through a narrow passage through a building in Prague's historic Malá Strana and similarly on a narrow bridge in Ostrava. In addition, they are used in various places in Prague and Brno where interlacing is used to shift the switches away from high-traffic intersections, in order to improve traffic flow.
In the rail system, it is used to overlap metro and normal rail lines; these use the same gauge, but the metro's third rail would otherwise intrude upon the standard railway kinematic envelope.
In 2008, a short new interlaced section was constructed for the Helsinki tram network, along the pedestrianisedMikonkatu, designed for the start of service in 2009. There is also a section of gauntlet track on Merikasarminkatu, also in Helsinki.
In Mannheim, gauntlet track is used to shift the switch out of the road to prevent the switch from being driven over by cars and trucks. Mannheim also uses gauntlet track to run trams within less space.
In Potsdam, a short section of interlaced track takes trams through the historic Nauener Tor into the old city.
In Stuttgart, gauntlet track was used extensively by the Stuttgarter Straßenbahnen in order to run services using the newer Stadtbahn, or light rail system, on route sections previously served by the older narrow-gauge tram system. The trams have now been completely phased out, save for occasional "old-timer" special runs, and all platforms are being converted from street-level to raised in order to accommodate the higher floors of the new vehicles.
Tram 10 negotiates the gauntlet track on the temporary bridge at Hoge Sluis, Amsterdam, 3 March 2012
Netherlands: short section of gauntlet track at the line 10 stop in Czaar Peterstraat in Amsterdam
To overcome space constraints, Amsterdam's tram network uses gauntlet track to increase space for shoppers in the 12 m (39 ft)-wide Leidsestraat in the city centre. In this busy and otherwise pedestrianised shopping street, the tram stops are located on the bridges over the canals, where more lateral space is available, permitting passing loops that can just accommodate two trams in each direction. Intermediate sections are gauntlet track. As service is frequent on routes 1, 2 and 5 which use this line, this arrangement often leads to delays. However, on line 10 in Czaar Peterstraat, the situation is reversed, and a short section of gauntlet track occurs in a line that is otherwise double, to make room for the platforms at the Eerste Leeghwaterstraat tram stop. Oddly, in a second radial route, at Utrechtsestraat, the passing places on the bridges are served by preset points with single track between them, rather than by gauntlet track. Amsterdam has two other short permanent sections of gauntlet track: opposite a loading bay in Amstelstraat (routes 9 and 14) and preceding the points entering the eastern terminal loop outside Amsterdam Centraal railway station. In addition, during the rebuilding of the bridge over the Amstel at Hoge Sluis, the temporary bridge that carried tramlines 7 and 10 was equipped with gauntlet track on the diagonal section at the eastern end, so as to leave enough room for the cycle path.
The Interislander rail-ferry ramps at Wellington and Picton have triple gauntlet track. At the ferry end of the ramp the outer tracks curve to the left and right to align with the tracks on the ferry rail deck.
Moscow tram tracks before entering a tunnel under Kursk railway
The Moscow tramway network has only one stretch of gauntlet track remaining in place. The five-track railway line just south of Kursky Terminal is crossed through a narrow tunnel built at the beginning of the 20th century and unsuitable for a two-track tram line. Other similar stretches were removed or re-organised, since according to the standards, gauntlet tracks on tram lines are only permitted as a temporary measure.
The tram network in Osinniki includes a narrow bridge with a gauntlet track across a railway line towards the Ossinikovskaya mine. However, since 2010 the stretch is out of use after the tram services in the area were cut.
The "Metrocentro T1" tram line of the Seville Metro that opened in 2007 features a 300 m section of interlaced track along the city's main pedestrian street. The section runs down Avenue de la Constitución, past the Seville Cathedral and World Heritage Site.
Roselle Park and Union stations, which are located on Conrail Shared Assets Operation's Lehigh Line in New Jersey, are equipped with gauntlet tracks. As New Jersey Transit's Raritan Valley Line trains use these stations, as well as freight trains of Conrail Shared Assets Operations use this track, the gauntlet track allows freight trains the extra clearance they may require, by moving the train further away from the platform edge. The gauntlet track is equipped with dispatcher controlled power switches. Or rather the gauntlet track allows the passenger train to get closer to the platform.
Gauntlet track on Conrail Shared Assets Operation Lehigh Line at New Jersey Transit's Raritan Valley Line Union, NJ station.
Amtrak's B&P Tunnel, underneath Baltimore on the Northeast Corridor, was equipped with a point gauntlet on one of its two tracks. Installed by the Pennsylvania Railroad in the mid-1950s to allow TOFC trains to fit through the tunnel, Amtrak removed it in the mid-1990s after most freight trains had been routed away from the Northeast Corridor.
The San Francisco cable car system features three areas with gauntlet tracks where the outer rail of the inner track is shared as the inner rail of the outer track for two sections of tracks: on Washington Street between Mason Street and Powell Street, on Powell Street (north of Washington Street) onto Jackson Street to the point of divergence of the Powell Street lines at Jackson Street and Mason Street, and on Hyde Street between Jackson Street and Washington Street. On Washington Street, the gauntlet track begins at a manual switch mid-block where Powell Street cable cars travel the right side of the gauntlet track and turn right onto Powell Street towards Market Street. Cable cars making non-revenue runs (such as those entering or leaving the car barn) normally bear left onto the left side of the gauntlet track which then turns left onto Powell Street heading north. On Powell and Jackson Streets, the gauntlet track also begins at a manual switch located mid-block on the northbound side of Powell Street north of Washington Street. This is where the two Powell Street lines diverge on a downhill section of Powell Street, with the Powell-Hyde line switching to the left side and the Powell-Mason line proceeding straight onto the right side. From there, the cable cars run on gauntlet track which turns left onto Jackson Street, continuing uphill for one block until the Mason line turns right onto Mason Street. On Hyde Street, the gauntlet track is located on the southbound side where California Street cable cars coming from the barn use the right side (forward-facing) of the gauntlet track to access their revenue tracks on California Street to begin their revenue service.