Finding these was a bit of a challenge since they were transferred on TOPS from Gresty Green to Basford Hall on Wednesday evening, where they were hard to find amongst the other FSAs there.
Six FSAs stand out as the ones you are looking for - 608045, 608046, 608389, 608390, 608463 and 608474.
The first two (045/046) are from the pool used on Hartlepool concrete segment traffic. Their last workings on this circuit last year were 4M52 Hartlepool - Grain 04/12, 4E52 Grain - Hartlepool 05/12, 4M52 Hartlepool - Willesden 05/12, and 4E54 Willesden - Hunslet Sidings 06/12. They are then shown moving empty (with the cassettes used for loading the concrete segments presumably removed at some point) on 27th January this year on a 6D66 from Hunslet to Doncaster Railport. After loading with the green containers they formed a 6M70 from Doncaster Railport to Crewe Gresty Green on the same day. This is pictured passing Woodburn Junction - the train later called in at Earles to pick up 608389 / 608390 (see below).
https://www.flickr.com/photos/49068127@N06/55064516850/ (Photo: Gavin B)
The photo linked at the end of
post #93 shows some of those green containers loaded to an IKA in a siding near Doncaster Railport during accident recovery work in 2022 - possibly they were still there after that use.
The other 4 FSAs (389 / 390 / 463 / 474) are in a pool by themselves which appears to be for wagons waiting maintenance or in restricted use. 608463 / 608474 working as a pair appear to have been out of use on regular Freightliner traffic since July 2023, when they were moved empty on 24/07 on a 4V54 Southampton Maritime - Bristol Freightliner terminal for storage. A YouTube video titled "
Bristol Freightliner Railport; 70016 collects stored container flats" shows 70016 collecting a short rake of Freightliner flats for movement to Basford Hall as a 4M20 on 13/10/23. 608463 / 608474 were included in this move, and reached Guide Bridge on 09/11/23 on a 4H67 wagon trip for maintenance. On 16/11/23 they moved back to Basford Hall on a 6K68 trip, and the wagons are shown on TOPS acquiring their containers while at Crewe (although it might have been done at Guide Bridge and updated later) with no other movements recorded apart from being tripped to Gresty Green and back.
608389 (working in a pair with 608390) appears to have been out of use on regular Freightliner workings since July 2024. It moved from Basford Hall to Guide Bridge on the 6H67 wagon trip on 11/07/24, then returned to Basford Hall on 4K66 on 23/07/24, moving onward to Hunslet on the 6E53 wagon trip the following day. TOPS shows this wagon acquiring the containers at Leeds Midland Road. On November 25th (either 2024 or 2025) it worked from Hunslet to Doncaster Railport and back as 6G01 / 6G02. At some point it was moved to Earles Sidings (possibly detached en route from one of the regular Hunslet to Tunstead wagon moves) and from there it was attached to the 27th January 6M70 movement to Crewe Gresty Green which had originated from Doncaster Railport with 66415 hauling 608045 / 608046 (mentioned above). The extra two wagons in the consist can be seen as 6M70 passes Hale in the gloom:
https://www.flickr.com/photos/142410950@N03/55064093922/ (Photo: Colin Peter Hobson)
I'm not sure about the current intended use of these low-height containers - I remember them originally being used on ballast / spoil traffic loaded to FEAs, where each container was roughly equivalent to a coalfish in terms of capacity. I think this might have been around the time of the West Coast Route modernisation, when Forders Sidings were in use as part of the project - I guess these containers were a quick way of providing extra capacity for ballast / spoil traffic without building more wagons.