Another new feature I noticed this week was a couple of substantial metal ladders fixed to the cutting walls on the route up to Edge Hill.
Maybe these are for emergency use or easier engineering access.
Those are cable ladders and not climbing ladders (hence them having "DO NOT CLIMB" plastered all over them!) One of the changes they are making to the trackside equipment is re-locating the cabinets topside so maintenance can be done without needing to go trackside, hence the need for regular ladders to run the cables up and out of the cutting.