I think the daytime Fishguard boat train is indeed currently booked as a pair of 153s. Agree it should be a 175 or 158 but there isnt enough 175s to cover the existing 175s diagrams at the moment it seems with many of the Manchester/Holyhead to South Wales workings either a 150 or pair of 153s. Also the 158s are pretty much tied to the Camrbian/Birmingham/Holyhead workings.
I know I used the words "short term" but perhaps I should have said medium term as I appreciate there isn't the availability of 158s or 175s to deliver a decent Fishguard boat train right now. A pair of 153s is at least better than a 150 or a single 153.
I assume once the 197s arrive the boat train will be booked for a 197 and the 153s being retained will just work Heart of Wales and Shrewsbury-Crewe local services.
I think that all Pembroke Dock's will also be 197s now the plan has changed from using 170s. Will they be 2 or 3 car 197s?
I had assumed the 153s would be replacing the 170s everywhere the latter had been intended to work, although given that TfW would need to retain practically all their 153s to have as many pairs of 153 as they have 170s then perhaps I was mistaken. How many 153s are being retained?
I guess 197s on the Pembroke Dock branch could make sense as a shuttle to Whitland (perhaps they will accelerate fast enough to run hourly) if there was something higher quality to connect onto at Whitland.
A class 197 on the boat train won't be much of a change in quality compared to 153s and 150s; they certainly aren't the "3-car DMUs with near-intercity ambiance" that ideally would be provided. Currently, only 158s/159s and 175 fit that description and there aren't enough of them - I really wanted whatever replaced Arriva Trains Wales to do something about that (ideally as a bi-mode) but so far nothing of the sort has appeared.