Without any necessarily particular relevance to this incident, I think that, over say the last 25 years : -
- increasing incompatibility of different rolling stock (for assisting failed trains purposes) using the same route,
- far more complex on-board systems (including heating/ventilation/air-conditioning),
- the frequent (but not universal) absence of opening windows, and
- the unsurprising paucity of self-powered traction that can be deployed for the very occasional rescue mission needed on largely electrified routes deprived of power, -
are all factors that contribute to this sort of modern-day incident having far more potential to become an extraordinarily protracted and complex affair, leading to very difficult circumstances for passengers, those staff on-site, and those situated remotely trying to take the right decisions, alike, in order to overcome the problems and get things moving again.
This is not to denigrate the efforts of staff having first-hand involvement at the time : I think that instances of anyone such not acting to the best of their ability in decisions and actions in trying to reach resolution would be very few indeed.
In the quoted recent case, I would feel confident that the Thameslink staff involved, particularly those on-site including technical, but most definitely the driver, would have felt under immense pressure, as the clock ticked on and on, to finally extricate the train and its passengers, many traumatised in various ways and degrees, from its difficult location after so long.
Some of us may recall the incident around Huntingdon not so long ago when a pantograph/overhead Line dewirement incident led to several trains becoming marooned, with at least one GNER set being stationary without auxiliary systems power, for - four hours was it? - and as a largely enclosed unit, conditions in the passenger accommodation became intolerable, yet the train staff faced the conflict of needing fresh air ingress, but the then operating instructions (doubtless not forseeing such a situation, and probably since amended) not permitting doors to be opened.
When introduced (and maybe still), Virgin's Pendolino Class 390 units were considered a 'sealed train' as far as air supply and temperature were concerned, presumably so that air-con/heat could be controlled most effectively : Fine as long as the exterior power supply and/or back-up batteries last, but after that ....
The understandable urge of some passengers, marooned for several hours, and feeling frustration, pressure of not being able to get to where they should have been, elements of claustrophobia, or just helplessness, to get out by using emergency door releases causes its own problems, and on-board staff can have great difficulty stemming the 'If they can get out, so can I' syndrome. And if they're in a conductor-rail electrified area, they can be in additional danger, and getting the juice off for their safety can extend the area of disruption.
Paradoxically, passengers on the track of their own volition can end up being the only thing preventing getting the show moving again, if the original problems have been overcome: Of course movements cannot recommence until everyone is sure that the line is clear of people.
Then when passengers put through such horrendous delays finally (if not detrained and left the railway at some other point) somehow land at a station (not necessarily their destination, or even one where sudden large numbers can be satisfactorily handled), resident staffing levels (if any, especially at certain times of day) or mobile staff called-in (if they can be arranged in time, given sometimes short notice of a train becoming able to move to a particular station), more often than not are understandably inadequate for, or logistically cannot satisfactorily handle, the needs of large numbers of passengers needing assistance after a prolonged hold-up experience.
This latter point has, I think, been demonstrated again just in the last few days, when Stagecoach South West Trains' passengers have had an, at times, tough week, culminating in last Thursday (09th) evening's severe hold-ups, reportedly through loss of signalling control by Wimbledon box of a large area somewhere in the Clapham-Waterloo area, plus loss of 3rd-rail power beyond Woking all around the Ash/Farnborough area, apparently through vandalism attack on cabling. This led to trains becoming stopped for very long periods, reportedly becoming as much as six hours late (I'm confident that some reached at least four hours : E.g. the 18:12 ex Waterloo-Alton got to destination at about 23:45). See various BBC News items here :
http://www.bbc.co.uk/search/news/?q=Waterloo