Seems to be a rising problem recently with a number of incidents I've dealt with or heard about, across a number of fleets. Also one or two where the units have become electrically uncoupled and then refused to couple back up, on occasion resulting in one of the multiple units shutting down because it had no input from an active driver's cab for so long. Admittedly I don't deal with the 80x fleet, though. It should theoretically have still been possible to draw up another train (entirely unrelated to the failed one) alongside and cross the passengers over. The formal version of such a process was invented in Europe, I believe, and is still known by some in the UK as "transboardment" (loosely derived from the French term for it). Nowadays there are side-to-side evacuation "ramps" in certain areas of the country which can be deployed quite quickly via a MOM's van or similar. Not sure if the Wessex area has them. They are used to bridge the gap between trains. Consideration does need to be given to doorway widths - eg. the ramps may be unsuitable for Mk3 end doors, but wider doors should be fine. In a worst-case scenario you can also use a wheelchair ramp between some types of trains. Certainly some Bombardier stock, although not sure about Hitachi stuff. It does depend how far the trains are from each other - if the "six-foot" between two running lines is too far apart or the two lines are on too much of a camber/tilt, it can be impossible for any ramp solution to work. I believe a Voyager was used to recover passengers from the Watford incident precisely because it was a DMU, and the state of the OHLE did not allow an EMU to operate. Other than the VTWC Voyagers, the south end of the WCML has precious few suitable DMUs for large volumes of passengers. Relying on computers without a proper override system (able to be operated with suitable training) is certainly a disaster waiting to happen. Some override systems that I see are electronic in and of themselves. Not great, really!