David,
Thank you, the problem is despite looking, including on slightly dubious potentially virus riddden websites, I have not found a full manual. Usually I manage to find some suitable documentation, or manage to find my own way through it, but this is one of those times that I cannot and a manual eludes me.
(I still think your monorail would need some form of signalling, or control and command in modern parlance. Otherwise, when a some hero or other throws a spanner in the works and said german lady and associated cat have to use the monorail to head to the escape pod, you need to also be able to let goons come the otherway as well!
)
Regards
Ian