according to http://www.firstgreatwestern.co.uk/About-Us/Our-business/Extra-capacity-across-the-network
services between reading and paddington can't be longer than 5 carriages. is that right?
I think some of the platforms are only 5 coach lengths long, this prohibits any trains stopping there being lengthened beyond those 5 coaches unless either there is a history of it happening (grandfather rights) or the train is equipt with SDO, and I think neither applies in this case.
I'm sure there was an issue at Walkden a couple of years back with using a pair of 156s on one of the services which meant it could no longer call there (it had previously been a combination of 142/150 units) due to a door being off the platform.
It makes sense to apply to automatic door stock without SDO as all the doors would be released just as they would be with slam-door stock.
Some short platforms at Midland Mainline stations possibly are still called at by EMT HSTs without SDO.
according to http://www.firstgreatwestern.co.uk/About-Us/Our-business/Extra-capacity-across-the-network
services between reading and paddington can't be longer than 5 carriages. is that right?
Yes if they stop at certain stations. In fact if the slow services go along the main lines they cannot be longer than 3 cars if they call at langley...