Just as the sun is setting, 20905 & 20901 pass Hatton on 11 May 2015 with the 7X09 11:47 Old Dalby to West Ruislip underground stock move, conveying a recently built S Stock unit. These new underground trains are built by Bombardier Transportation at Derby, and tested at the Old Dalby test track, before heading to London for commissioning. The trains are always worked south by two pairs of Class 20s, in this case the pair on the rear are 20118 & 20132.