The Kilsby Tunnel is a railway tunnel on the West Coast Main Line in England, near the village of Kilsby in Northamptonshire, roughly 5 miles (8 km) southeast of Rugby. It is long. The Kilsby Tunnel was designed and engineered by Robert Stephenson for the London & Birmingham Railway (L&BR). It was constructed by contractors Joseph Nowell & Sons and later by the L&BR. It took much longer to construct and exceeded its estimated cost, attributed to a roof collapse and consequential flooding. At the time of its opening in 1838, it was the longest railway tunnel ever constructed. The tunnel had atypically large ventilation shafts, because of a lack of experience as to how much ventilation would be needed for steam locomotives to pass through. On opening in 1838, the tunnel was single track and in 1879, double-track was laid. In March 1987, Kilsby Tunnel portals and its two ventilation shafts were given listed status. History Construction In the 1830s, Robert Stephenson developed the London & Birmingham Railway (L&BR) (later known as the West Coast Main Line). After opposition from several landowners and proprietors in Northampton in July 1832, the House of Lords rejected the original bill to authorise construction of the line. Stephenson surveyed an alternative route to the west of the town that included Kilsby Tunnel. The 2,423 yard tunnel would be the world's longest railway tunnel. In May 1835, Joseph Nowell & Sons was awarded the tunnel contract, which was valued at £98,988. Construction proved to be less than straightforward. Within months of work commencing, the second of the working shafts was flooded because of large amounts of quicksand not revealed by trial borings into the hill. Similar problems had been encountered during the construction of Blisworth Tunnel on the Grand Union Canal a few decades earlier. Problems posed by the quicksand at tunnel level were so severe that abandoning the shaft and restarting work elsewhere was considered. Stress from the project was said to have caused Joseph Nowell's ill-health and death. At the recommendation of George Stephenson, several steam-powered pumps were installed to extract water from the quicksand inside the tunnel. The pumps removed up to 2,000 gallons of water from a depth of 120 feet every minute of operation and took up to eight months. Seven more shafts were sunk to install timber cylinders to hold back the sand. During this time, multiple attempts