Indeed, and with the exception of the existing 1M36 / 1S05 return working from Shieldmuir to Daventry, pretty much the whole pattern of Royal Mail timings and headcodes have changed.
The previous 1M44 16:20 Shieldmuir - Warrington and 1A97 onward to the PRDC have been replaced by a 1M27 12:35 Shieldmuir - PRDC.
Northbound, 1M96 16:16 PRDC - Warrington and 1S96 onward to Shieldmuir have been replaced by 1F05 12:26 PRDC - Warrington and 1S24 onward to Shieldmuir.
The East coast mails have effectively been sacrificed to provide units to run a new 1M55 14:19 Shieldmuir - Daventry and 1S55 20:44 return.
Incidentally, this means that all the mail units in use on a given day can be seen in a two-hour period between 15:30 and 17:30 passing through Wigan on 1M27 / 1M55 / 1S24 / 1S05.
While in theory there should be enough units to run the east coast mails in addition to the above, I think in practice it might be a struggle. When the new Daventry terminal was opened, the 1M36 service (which started in August 2023) was initially introduced in addition to the rest of the trains, but not long after that, the 1M03 Shieldmuir - Warrington and 1S55 return were discontinued. I suspect this was due to issues with unit availability.
In a thread from last year, it was asked whether Royal Mail would be introducing more services to the "South Midlands Super Hub" at Daventry in 2024. I commented that
there were paths but I wasn't sure where the units would come from - but now it looks like we have an answer - from the east coast main line!
I dug up an old
DB customer newsletter from 2020 which mentions Royal Mail and "
a five-year contract extension to operate and maintain its fleet of 15 Class 325 units". Surprising to think the 325s are now 30 years old! I think DB basically run whatever pattern of services Royal Mail require using their fleet of 325s, and presumably Royal Mail are prioritising an extra Daventry train over the Low Fell service. One thing that counts against the east coast service is that it used two units, each of which only worked one train per day, either northbound or southbound. If the Daventry trains are loaded both ways it means each unit used does two loaded runs per day instead of one.
I believe the units are Royal Mail owned, yes. It will be interesting to see what happens when the contract to operate them is up for renewal, which should be next year judging from that newsletter. If Royal Mail want to run more trains, they could potentially tender for that, maybe separately from the operation of the existing 325 fleet. I think there was a period from 2006-2012 (or something like that) when the east coast trains ceased running before resuming again, so it's not impossible they could make a comeback at some point. On the other hand, Royal Mail may view the situation as that they have an existing fleet of road and rail vehicles, with the priority being to use them cost-effectively rather than pay to hire in more resources from outside. I don't know that much about the overall Royal Mail logistics operation (for example if it's all done in-house or some road haulage is contracted out, costs of road vs rail), so it's hard to say.
***
On that old thread I already mentioned about the Daventry mail trains, we were discussing the lack of wires into the terminal and the need for diesel-haulage from Daventry Reception Sidings. There was a brief attempt to use the Daventry shunt loco when the trains first started, but that was soon abandoned in favour of a DB class 66 outbased at Daventry just for the shunt moves. Adding to the mystery, as far as I can tell the Daventry shunt loco at the time was an ex British Steel machine (numbered 460, GEC 5425 of 1976). Was there a brief, glorious moment where a loco more at home at Redcar steelworks was hauling mail trains? Or was it just a fever dream based on an inadequate knowledge of the Daventry shunter fleet?
Anyway, in that thread I suggested a Class 08 might be more successful hauling mail units, and lo and behold 08629 is now hauling the mail units to the terminal. Photos show 08629 under overhaul during September 2023 (shunting Eastleigh Yard previously), and class 66s were in use until December at least, suggesting 08629 arrived at Daventry sometime around the beginning of the year.
Good to find some decent shots of operations on the branch (by robmcrorie on flickr). The secret life of a mail gronk revealed...
Previous operation using class 66:
https://www.flickr.com/photos/robmcrorie/53408404313/
08629 hauling the units of 1M36 along the branch:
https://www.flickr.com/photos/robmcrorie/53649686465/
Drone view of the 08 on the branch:
https://www.flickr.com/photos/robmcrorie/53649699982/
Great drone shot of a 325 in the terminal:
https://www.flickr.com/photos/robmcrorie/53650919619/