I wonder what might happen if enough passengers refused to accept a decision to terminate their train short of destination, by remaining on the train & blocking the doors from closing ?
Yes, the police might be called, but by the time they arrived, the delay could be more than if the train had been allowed to proceed to its final destination.
They'd end up back where they started eventually or banged up. Wouldn't be wise to object.
But the train could not move if passengers were blocking the doorway. Of course, people would move if/when the police arrived and told them to move -- but at some locations, it would possibly take the police an hour or more to get there....... and some courts tend to look unfavourably at organisations that have a history of poor treatment of customers.
This is an emerging problem with Southern's prevalent ideas to turn back late running trains at various locations. There have been previous passenger uprisings at Hurst Green, Crowborough, and stations on the Southampton Central route, to name just three. BTP do generally send resources, but with ETAs being so lengthy at times, and with conventional police forces only responding to the most serious issues, unfortunately the next train usually ends up being ready to pick up everyone before the police get there. Many of the regular but obstructive passengers are just about knowledgable enough to only stop forcing the doors or leaning on the train when the next one is due to arrive shortly.
Unless the signaller brings something to the attention of Control they weren't aware of, or they hadn't realised. Or is it preferable to notice someone is about to balls something up, and keep your mouth shut and let things pan out? For instance, the signaller may be aware of an unscheduled conflicting move, or a unit berthed on the stops of a bay platform preventing the turnback move.
It's definitely not a useful strategy to keep quiet about an emerging issue. On some occasions I have known signallers, more junior controllers or train crew prevent the controllers in charge from making a serious mess of terminating a train somewhere which was completely useless. There are also some locations which are not permitted for terminating trains in certain or all circumstances (be it length of the train, no suitable procedure for ECS moves, no access for wheelchair passengers, etc.), but these constraints may not be easily interpreted by a controller having to make judgments about a large chunk of a network all at once.
By which time the traincrew are in a nice warm taxi being whisked back to their home depot so the rebellious punters would be on a hiding to nothing. Switch the engines & lights off. They soon get the picture.
Most unlikely at many turnback locations. Many of them will not be permitted locations to berth stock, especially away from major interchanges. Therefore someone has to stay with the train or move it. Also not a great idea to lock people into a train - egresses and passcoms can be troublesome when trying to restart a train which has been shut down.
In which case you're lucky to have such supportive management, most and this goes for both train and track management seem to be more concerned about delay minutes.
Which by the way I do believe that Signallers do need to have some flexibility in how they platform trains after all they have to and do their best to keep the network moving.
Signallers do ultimately have flexibility about platform usage during disruption, so long as the platform has access to/from the routes a certain train service requires, the train itself fits in the platform (or has SDO) and so on. They will be expected to respond to the working timetable and carriage working documents during normal working, and major TOCs with large termini will usually spell out stock allocations and all splits/attachments, during all but the most major disruption.