There are issues on the Cromer line, that is a given, AHB's are on local, or if not a caution over them, this applies to all trains, regardless of type, to avoid an incident, whereby a Signaller mistakes what type of unit is on the line, thus 156's are affected by default, WHEN was the crossing equipment modified ? as last year there were no problems at all, they started all of sudden when the 755's kicked off, the 755's have all been modified since, by removing flange lubricators, and having citrous oil applied to shine the wheels a bit, it is fair to say that similar units have had problems in Italy, Holland and Germany. As for priority, the line is run by Class 2's and dealt with as such, The tanks are Class 6 and take a lower priority.
Was it not said when the trains were first ordered that no one on the Ops side of GA were consulted, they were ordered by the commercial side, so there maybe the first glimpses of issues to come back then.
The 755's certainly do not like the UK network it seems, but that is not really a NR fault. HOWEVER NR WILL one assumes have to alter things at great cost to enable GA to run the darn things.
There has also been days on end with no service on the Felixstowe, for no real reason at all, None on the Sudbury, but they have not had any test trips at all yet on there, so that is one reason, if no spare 156's
Fuel is another big issue, and is causing a lot of delays and cancellations.