Sorry about the bad photos, I can return later to take some better ones with a proper camera if need be. Only one plant that I could see and though it doesn’t show in the photos, the undersides were covered in spores that matched sighting 22847.
Certainly looks like it Ned will await David's ID - interesting that the other Canberra location of this invasive fern is also a bridge - where the Federal Highway cross Horespark drive