Translink are proposing to develop a ballast cleaning facility at Ballinderry on this branch.
Presumably this will mean heavy ballast trains, (GM locos and wagons) using the full length of the branch and access points at Antrim and Lisburn
The tree I originally posted about has been removed and there were several vans parked at the nearest track access point between Brookhill Bridge and Brookmount on a number of occasions recently.
Just my observations from driving past, I don't know what they were doing on the line.