Aye, the ex GWR unit will be for rescue purposes, but not because they have a pantograph, as they are being tested on the G&SW between Kilmarnock and Dumfries which is not wired, but more likely because the ex GWR ones have already been extensively tested after improvement works by Brodie Engineering over the last 12months and are deemed more reliable.
They have done limited tests on the Ayr line, but mostly on the Kilmarnock-Dumfries route due to more path availability.
There are also wires north of Barrhead.
Apparently the GWR units have been tested in both modes on all of the G&SWR lines. It tends to be useful to run under the wires, so to solve any issues they can just raise the pantograph. It remains to be seen whether the TfW units at Kilmarnock, or the Northern units will receive the same improvements.
Many thanks for the updates. Interesting reading. I assuming the reason for removing the 3rd rail power is because they can potentially use platform 3 at Southport which is primary used by Merseyrail for Liverpool bound trains and is 3rd rail enabled but is occasionally used by Northern for Wigan bound trains ?
It’s nothing to do with that. All 319s had their 3rd rail shoes removed when they were returned to Porterbrook off lease by Thameslink, before any of them entered service with Northern and before the 769 conversion was devised. At that time they could not run to Southport and did not encounter any third rail.
The GWR 769s had additional work to reinstate DC equipment that the Northern and TfW units didn’t, because the line they were intended to run on, the North Downs line is a mixture of 3rd rail and unelectrified sections.
It would be nice on an integrated railway if the failed 769s that have been stranded at Southport for weeks at a time could have run back to Allerton the most direct route via Liverpool Central, under their own power using the 3rd rail, rather than having to wait to be dragged back to Springs Branch, although some have been able to be taken on the back of an in service train.
It seems to be standard to remove 3rd rail equipment from off lease fleets dual voltage that may be leased again outside the Southern Region. The same was done with 365s.