Burlington Tunnel

The Burlington Tunnel is a railroad tunnel located in Burlington, Vermont and is currently owned and operated by the New England Central Railroad . According to the inscription on its southern entrance, the Burlington Tunnel was constructed beginning on 1 November 1860, and completed on 17 May 1861 for a predecessor railroad to the Central Vermont Railway. The tunnel runs in a northeast/southwest curve, while the external approach trackage runs from south to east. The street overpassing the Burlington Tunnel is North Avenue which has an Average Annual Daily Traffic of about 12,000 vehicles.
The Burlington Rail Tunnel, located at Milepost 1.15 of the NECR Winooski spur line, is a 340-foot long brick masonry horseshoe shaped tunnel that passes through the sandy ridge supporting North Avenue on a curve of approximately four degrees. North Avenue runs in a north to south direction while the tunnel runs approximately in an east to west direction. The tunnel, constructed in 1860, originally had an overall height of approximately 17 feet and a width of roughly 14 feet at the base, increasing to approximately 16 feet wide at approximately 9 feet above top of rail. The tunnel provides passage for a single track over ballast. The track grade is generally level. A major gas line which runs from a building on the southeast quadrant of the existing tunnel structure easterly across the wetlands and under the Burlington Connector highway to the east. There is also an extensive aerial power line system which runs along the railroad right-of-way and up over North Avenue.

Wikipedia