The reason I ask if they will be in passenger service for the Dec TT is due to the issues regarding the introduction of the Class 385 being delayed which obviously is having a impact on the HST introduction.
I don't believe that 385 delays are impacting on the HST introduction at all - it's the HST refurb delays that are having an impact on HST introduction!
My understanding of the stock situation around 385s/365s/170s/HSTs...
- 385s with windscreen mods are passed for passenger service and a small number (less than 10) have had the mods. These are likely to enter service in the next couple of weeks. Remaining units will be modded but this will probably happen fairly quickly.
- 10 365s (as of a couple of hours ago) are in Scotland and 6 or 8 of those are modded and good for service - they are expected to stay here for a year.
- There were a total of 16 170s to go to Northern - 4 in March, 6 in July and 6 in November.
- 4x modified HST sets were to be available for the May timetable change, this didn't happen and Scotrail have apparently asked about using unmodified stock from December
I suspect the reason that 365s were gauge cleared for more than just the E&G suggests that they will end up covering what were planned to stay as diesel routes pending the completion of 385 deliveries to cover for the delayed HSTs, but that another difficult period is on the way, hence the request to operate unmodified stock from December.
It looks like 365s will now easily cover the 170s going south in July and there should almost certainly be enough 385s in service by November to cover those too (if not moving 365s off the core E&G route as well) - this should really be the situation by mid-July but training/mileage accumulation/rostering will all need to settle down. December (or "after October") should also bring electrification of Stirling/Dunblane/Alloa (SDA) and could use 365/385 depending upon availability (was SDA one of the gauge-cleared routes for 365s?), freeing up DMUs. It's just whether there's enough electrification in November to free up enough DMUs to cover for those leaving and the "missing" HSTs... SDA, Grahamston and possibly Shotts services would be the likely candidates.
I've been critical about some operational decisions, but I'm actually pretty impressed with the part of Abellio Scotrail looking after all of this - they are juggling rolling stock procurement/testing, refurbishment delays, electrification projects, drivers, guards and training and pretty much managing to keep the show on the road.