Fortunately, the locomotives couple directly to the 345s without barrier wagons. There are only 18 7-car 345s out east at the moment - 345003/5-17/22/42/56/64. The 7-cars have to go via the North London Line in any case.The alternative of about 20 trains (each way) needing to be coupled to barrier wagons, then shuttling back and forth on changeover date seems much harder. Even if it is easiest for irregular stock transfers.
Looking at returns to Old Oak Depot yesterday on TrackIt, I was surprised to note that the unit on evening test trips to Heathrow last night was reported as '5I25' (see below), suggesting 345025, which has previously been discussed as a 'tunnel' unit. The '5Ixx' entries tend to be fairly reliable although occasionally there is a mistake made. If it was 345025 running to Heathrow last night, maybe it is testing a software version that does enable running on both. Clearly I could just be drawing the wrong conclusions or it could be a miskey.I don’t believe there is a software version that allows both running on central core section and under National Train Control (AWS/TPWS) or ETCS
Finally, and also made up from speculating on observations from Old Oak Depot movements, and the suggestion that a set of spare cars gets sent from Worksop to Old Oak Depot every week, are 345051 and 345020 perhaps the next two conversions to 9-car completed? Again, I could easily be drawing the wrong conclusions but 345039 and 345052 made the same moves on 10 February and 11 February as those shown for 345051 and 345020 more recently.345039/052 now showing on the system as 9 car sets, I'm told.
I don't think 345039 or 345052 have been out in passenger service yet following their conversion reported upthread, unlike 345047 and 345057 which appear to be part of the operational pool of units on passenger services making 20 units available for passenger service out west.