70807 passes underneath the new road bridge at Challow on 18 February 2015 with the 6M50 07:55 Westbury to Bescot engineers train, running on the up main, rather than the up relief line, as booked. The A417 was closed for several months in late 2014 to allow Network Rail to rebuild Challow bridge, as part of the Great Western Mainline electrification programme.