Cheers guys - seemed mega power for such a short train!
Top and tailed because there are limited opportunities to get off the DC lines, it actually exited at the Euston end and reversed there.
It is quite common for engineers trains of all lengths to work top and tail for operational purposes, the rear engine should not apply power and, in most cases, is not even manned.
The one exception to that rule, and you might have seen it round the Milton Keynes area, is the High Output Ballast Cleaner which is worked by top & tail DBS 66s. They are both manned, the drivers are in radio contact and the rear one is authorised to, and has to, push in order to get the train moving at a sensible speed in places. Quite an impressive sight watching it storm through somewhere like Harrow & Wealdstone with a 66 flat out on either end
