I’m not certain, but I believe that what you can see is in connection with work being carried out on the railway bridge over the River Avon.
You're right, according to
this from the local councillor.
Network Rail to be working in Staverton by trevorcarbin on 2 August, 2021
They have some work to do on the railway bridge over the Avon just outside the village. Access to the site compound will be via the track off the B3105 by the road/rail bridge, with the compound being in the triangular land next to the railway.
From 16/08/2021 Traffic Management will be in place. This will be removed at weekends until October when it will be in place permanently until the work finishes in March.
They will also be carrying out repair work to the access road while setting up the site compound. From 23/08/2021 they will start installing cabins and site welfare and from 30/8/2021 will begin installing scaffolding on the bridge. Between 24 September and the end of March 2022 the main work to grit blast and repaint the structure will take place.
That access route runs beside the line from Melksham and then along the ex-chord, to the work site at its east end - where DaveHarries saw it.
There don't seem to be any possessions in the EAS, whatever that means.
