Trains being too long for the platform: clarification needed

[startingaparty]

I've noticed on the Northern twitter page that one excuse for services being made up of three carriages instead of, say, six carriages is that longer trains wouldn't be able to work certain routes because some stations have platforms which aren't long enough open all the doors on. Okay, sounds reasonable. However, on the Manchester Airport to Blackpool North route the six-carriage trains regularly stop at Blackrod and Adlington (Lancs) and an announcement is made by the conductor that any passengers wishing to alight at these stations and sitting at the rear of the train should move forward a few carriages.

Why can't this be done on all routes and thereby make provision for more capacity on high demand routes where the platforms might not be long enough to open all the doors?

 

[PupCuff]

Not all trains are fitted with the required technology to only open the doors adjacent to the platform where the train can't be fully accommodated (called Selective Door Operation - SDO - or sometimes Unit Deselect or Unit Door Blocking - UDS/UDB). Pretty much all recent units do, and most units from the early 2000s, but before that quite often they don't.

Northern operate some services with trains which can do this (eg 195s and 331s) and some services with trains which can't (eg 150s or 323s). If they had a fully modern fleet then in theory they could.

 

[Gems]

I've noticed on the Northern twitter page that one excuse for services being made up of three carriages instead of, say, six carriages is that longer trains wouldn't be able to work certain routes because some stations have platforms which aren't long enough open all the doors on. Okay, sounds reasonable. However, on the Manchester Airport to Blackpool North route the six-carriage trains regularly stop at Blackrod and Adlington (Lancs) and an announcement is made by the conductor that any passengers wishing to alight at these stations and sitting at the rear of the train should move forward a few carriages.

Why can't this be done on all routes and thereby make provision for more capacity on high demand routes where the platforms might not be long enough to open all the doors?

Depends if it has ASDO. Even if it doesn't it could still stop. But the doors being opened manually will add to serious delays. Financially it is better they don't.

 

[Some guy]

I've noticed on the Northern twitter page that one excuse for services being made up of three carriages instead of, say, six carriages is that longer trains wouldn't be able to work certain routes because some stations have platforms which aren't long enough open all the doors on. Okay, sounds reasonable. However, on the Manchester Airport to Blackpool North route the six-carriage trains regularly stop at Blackrod and Adlington (Lancs) and an announcement is made by the conductor that any passengers wishing to alight at these stations and sitting at the rear of the train should move forward a few carriages.

Why can't this be done on all routes and thereby make provision for more capacity on high demand routes where the platforms might not be long enough to open all the doors?

The short answer is northern still have late 80’s trash running along their network which don’t have ASDO only the CAF trains can do it. If they had more modern stock all over it would be possible