I noticed on RTT that all London Northwestern services were

carrying strange headcodes such as 2Z51. I could not work out why but then realised that all was not well with local services. In fact, there were no trains running on the up and down slow lines out of London due to, what I discovered later to be, a massive signalling failure at Euston. This also affected Virgin services causing many cancellations and hours of delays. 350119 and 350104 forms and empty coaching stock working from somewhere south that would then work a scratch service for beleaguered passengers waiting at Northampton.