A rail grinder?
No sorry.
One final clue : its not a powered vehicle.
A rail grinder?
DBSO?
RHTT wagon?
Is it a container wagon of some sort? (I'm really not clued up on wagon types!)You are half correct!
Finally!Yes its what I believe is called a cargo wagon that can go though the channel tunnel. We got there in the end!
View attachment 57102

Not a 66Class 66?
Not a 175.Class 175?
Class 444?
Class 458?
Afraid it's not any of those.Class 321?
Class 801?
Afraid it's not either of those, although the 801 was close...Class 387?