This line ran from Colwick Junction in Nottingham to Egginton Junction in South Derbyshire. The route planned took the line through Mapperley via the Mapperley Tunnel built to avoid attempting to get the railway over the ridge. The tunnel was in use by 1875 but suffered a roof collapse due to mining subsidence on 23 January 1925. A length of roof about 12 yards long collapsed, blocking the line with approximately 150 tons of rubble. Whilst repairs were undertaken traffic was diverted along the Nottingham Suburban Railway. The tunnel was repaired, but the continuing effects of subsidence resulted in speed restrictions in the 1950s and closure on 4 April 1960. The eastern portal is still open and accessible, and the tunnel itself is open to a point just west of the second air shaft (counting from the east). Beyond the second air shaft the tunnel has been filled with earth. The tunnel portal is on private property, and permission should be sought from the owner before entering. A large quantity of rubbish has been thrown down the second air shaft, creating an unstable pile in the tunnel which may collapse in the future, causing injury to anyone present. Nottingham Suburban Railway The Nottingham Suburban Railway was completed in 1889; it was only 3.5 miles long but had four tunnels. The line ran between a junction with the Great Northern Railway's Nottingham to Grantham line at Trent Lane in Sneinton, and the Great Northern Railway's Derbyshire and Staffordshire Extension line at Daybrook. It had stations at Sherwood, St Ann's Well and Thorney Wood. Ashwell Tunnel is entirely within Woodthorpe Park, Nottingham. The stately home in Woodthorpe Park is called Woodthorpe Grange and was once owned by Edward Parry, the designer and chief engineer of the Nottingham Suburban Railway. Both portals of this 70-yard long tunnel have been covered with earth and the tunnel itself is no longer accessible. At the north portal there is an accommodation bridge allowing Woodthorpe Drive to cross the railway line. The south side of this bridge has been bricked up and a full-sized model of a steam locomotive has been built into the brickwork. Sherwood Tunnel is the next tunnel south from Ashwell Tunnel. At the south end of Woodthorpe Park the line passed under the accommodation bridge for Sherwood Vale. This bridge still exists and marks the beginning of a short cutting leading to the