Bletchleyite
Veteran Member
I cannot understand the logic of ‘inserting’ the 153 into the middle of a 156. If the dogbox fails, the whole unit is then a failure, whereas if it’s bolted on at one end it’s simply uncoupled and the service can still run as a 156 or a 153.
Any advantage doing this over coupling it on the end?
If it was permanently in the formation it would be allowed to retain a non-compliant bog, because it's part of a unit that has a compliant one?
They could remove it to create more luggage/bike space, though.