So what will do they with the trains and crews? Can they be used elsewhere? Would they continue to train them because their agreement with the DfT says they need to be deployed or would common sense apply.It's definitely happened - I've been on one. I can't remember the circumstances, but a couple of years ago there was a brief phase where two Turbo units (at different times) had an extra coach inserted. I can't remember the specifics and I probably wouldn't have it written down anywhere, but I could be sure it's been mentioned on the forums before.
Stations like Dorking Deepdene can accommodate 4 coaches of MkI stock (source: Sectional Appendix). At that particular location, the length is 87.8 between the tops of the ramps, so with some careful positioning the doors could probably all fit on the platform, unless you went for the much simpler option of locking out the doors on the rear coach at one or two stations.
"Fire regs" (as they are known colloquially in the industry) will require a certain number of exits from each coach and each unit, thus you would not normally be permitted to run a formation with a unit where only one of its two coaches was accessible, as there would only be 4 available exits for passengers.
Some Redhill-Gatwick workings are DOO, not all, as far as I know. I seem to remember some of them, possibly some evening ones, are booked to run without any second member of crew at all. I'll have to ask a GWR guard next time I have a moment.
For Redhill-Gatwick, all platforms could easily accommodate any of the conceivable Turbo formations in use on the route, with the caveat that GWR services only call there in emergencies and therefore "once in a blue moon" etc. The shortest is Salfords which can hold 8 coaches of 377 stock. You can only dispatch from these stations with bodyside cameras anyway so a guard would need to be provided for that, without taking into account SDO.
I do get the feeling that the TL Programme does need to settle down before this sort of improvement is tackled, but I wouldn't necessarily agree that the positioning of the turnback platform is going to be any worse than if it was placed anywhere else within the current boundary of the station. If Platform 0 had been the bay platform then trains to or from Gatwick would still have had to cross the entire throat at the south of Redhill in order to get to or from the BML.
I'm not sure that anybody currently has the authority or money to sort some of those crossings out. You're quite right that it's not limited to the controlled ones - indeed, I'd be more worried about risk and misuse at some of the AHBC ones which have no permanent monitoring solution - but I guess that the more rural and lightly-used you go, the less investment there would be to build bridges and underpasses. Take Buckland AHBC as an example: you could use a bridge, such as crosses a lightly-used footpath and farm track just to the West, and drop the road down a little further (taking into account drainage from the hills to the north) but who's going to stump up the cash when the whole success of a 3tph timetable could also be affected by numerous existing flaws, such as flat junctions etc.?
So we have the paths; and the crews are there, indeed the trains could probably be there too. Oh dear!
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