Ashendon Junction

Ashendon Junction in Buckinghamshire, England, was a major mainline railway junction where, from July 1910, the Great Western Railway's (GWR) London-Birmingham direct route diverged from the Great Central Railway's (GCR) main London-Sheffield route. It was near the small village of Ashendon, about 10 miles north-east of Oxford.

The junction was where what is now the Chiltern Main Line (formerly the "Birmingham Direct Line" aka "Bicester cut-off" of the GWR), inaugurated in 1910, joined the post-1906 "Alternative Route" alignment of the GCR. It was located 3 miles 44 chains (5.71 km) north-west of today's Haddenham and Thame Parkway; 44 miles 4 chains (70.89 km) from London Paddington via Northolt Junction, and 45 miles 31 chains (73.04 km) from London Marylebone via Neasden and Northolt Junctions. It was a high-speed flying junction carrying southbound GWR trains from Birmingham via Bicester North (Engineer's Line Reference NAJ2) on an embankment with a girder bridge over the top of northbound Great Central trains travelling from London Marylebone on to the 90 mph five-mile link to Grendon Underwood Junction (Engineer's Line Reference GUA) where they rejoined the original Great Central Main Line towards Brackley and beyond to the East Midlands and North. The signal box, located on the up side of GCR tracks was the only one on the joint line of a GCR design. Signalling was also of the GCR upper quadrant type.