Route: Spirit Of Steam Service: 1148 Crewe to Hartford (Blackpool), Jubilee and Mark One set. Service oscillated badly then tipped over/derailed on the crossovers just north of the platform. I was doing 13 MPH well within the 20 MPH speed limit. 55% cutoff and light regulator, about 20%. Not recoverable, game over.
I couldn't replicate this bug but this might be a potential cause - if you look closely at the Jubilee's wheels, they are not touching the rails:
