Question: How long is the tunnel which Erstfeld railway station sits at the foot of the ramp to?
Context: Blea Moor Tunnel is a 2,629 yd (2,404 m) railway tunnel located between Ribblehead Viaduct and Dent railway station in England.  It is the longest tunnel on the Settle-Carlisle Line, being almost twice as long as the second longest tunnel, Rise Hill Tunnel.  Built by the Midland Railway, it took more than four years to complete, passes some 500 feet below the moor after which it was named, and was built with the aid of seven separate construction shafts sunk from the moor above.  This permitted sixteen separate gangs of workers to be used during construction (one from each open end and two from the foot of each of the shafts).  Four of these were subsequently filled in but three were retained for ventilation purposes and are still used as such today (with occasional ice accumulation problems: ).  At one point of the track's history, steam locomotives were tested for their worthiness by driving them through this tunnel. Lundamo Station (Norwegian: "Lundamo stasjon" ) is a railway station in the village of Lundamo in the municipality of Melhus in Sør-Trøndelag county, Norway.  The station is located on the Dovre Line, about 38 km south of Trondheim Central Station "(Trondheim S)" and about 515 km north of Oslo Central Station "(Oslo S)".  The station sits at an elevation of 34 m above sea level.  It is served by local trains to Røros Station.  The station was opened 1864 as part of the Trondhjem–Støren Line. Kandy railway station is a major railway station in Kandy, Sri Lanka.  The station is served by Sri Lanka Railways and is the primary railway station in Kandy and one of the most significant in the central hills.  The station sits on a branch of the Main Line, leading to the Matale Line. The Lemonnier premetro station is an underground tram station in the City of Brussels, Brussels, Belgium.  It is located near the crossroad between the Maurice Lemonnier boulevard and the small ring road.  It is part of the North-South Axis tunnel which crosses the city center from the Brussels-North railway station to the Albert premetro station.  Additional tunnel exits exist at the Brussels-South railway station as well as at the Lemonnier premetro station, allowing trams to leave or enter the tunnel at those points.  Currently, tram routes 51 and 82 enter the tunnel at Lemonnier toward the South.  Tram routes 3 and 4 as well as evening routes 31, and 32 also stop at Lemonnier.  The station is decorated with paintings by Hamsi Boubeker.  On a lower floor there is unused second station with two platforms.  In the tunnel between Annessens and Lemonnier there is a tunnel towards this station. The Gotthard Tunnel (German: "Gotthardtunnel" , Italian: "Galleria del San Gottardo" ) is a 15.003 km railway tunnel and forms the summit of the Gotthard Railway in Switzerland.  It connects Göschenen with Airolo and was the first tunnel through the Saint-Gotthard Massif in order to bypass the St Gotthard Pass.  It is built as one double-track, standard gauge tunnel.  When opened in 1882, the Gotthard Tunnel was the longest tunnel in the world. Erstfeld (German: "Bahnhof Erstfeld" ) is a railway station in the Swiss canton of Uri and municipality of Erstfeld.  The station is situated on the Gotthard railway, at the foot of the ramp up to the Gotthard Tunnel. Tsubame-Sanjō Station (燕三条駅 , Tsubame-Sanjō-eki ) is a railway station in Sanjō, Niigata, Japan, operated by East Japan Railway Company (JR East).  The station sits directly on the border of the cities of Sanjō and Tsubame.  As the station headquarters are located on the Sanjō side of the station, Tsubame-Sanjō Station is considered to be in Sanjō.  The station is located 293.8 kilometers from Tokyo , Melhus Station (Norwegian: "Melhus stasjon" ) is a railway station in the village of Melhus in the municipality of Melhus in Sør-Trøndelag county, Norway.  The station is located on the Dovre Line, about 21 km south of Trondheim Central Station "(Trondheim S)" and about 531 km north of Oslo Central Station "(Oslo S)".  The station sits at an elevation of 24 m above sea level.  It is served by local trains to Røros Station.  The station was opened 1993 and is somewhat south of the old station in Melhus. Warsaw Powiśle (Polish: "Warszawa Powiśle" ) is a railway station in Warsaw, Poland.  Located in the district of Powiśle stretching between Aleje Jerozolimskie near Rondo Charles'a de Gaulle'a (high-level entrance) and the intersection of Aleja 3 Maja and ul.  Kruczkowskiego (low-level entrance).  The station sits on a rail embankment extending from the terrace of the Vistula river on which the city centre is built, ending at its western side with the entrance to the Cross-City tunnel.  The station has two side platforms flanking the suburban tracks of the Warsaw Cross-City Line used by the regional trains run by Koleje Mazowieckie and Szybka Kolej Miejska.  The mainline tracks can be seen from the station.  They are located behind a fence, which extends for the length of the station.  The station building was designed by Arseniusz Romanowicz and Piotr Szymaniak in 1955.  The location allows for convenient transfers to city trams and buses serving the eastern part of the city centre. Granary Wharf is a mixed-use development that stands next to the brick tunnels beside the Leeds and Liverpool Canal, and the River Aire in Leeds, West Yorkshire, England.  Leeds City railway station sits above the brick tunnels on Dark Neville Street.  The tunnel complex is known locally as the Dark Arches.
Answer: 15.003 km