Picture the scenario.
I need to dig a 15m wide trench through a 25m tall sandy cliff, down to a depth of about 5m below the beach. The trench comes from about 20m back from the cliff face, effectivly 30m down, all the way through the cliff and out into the beach. I've got a very small area either side of the trench accesible, and the land happens to be SSSI, so really don't want to disturb it too much.
Is the easiest way to excavate from the top all the way down, or with a long-reach excavator from the beach? Are there excavators in existence that could do this?
Hopefully someone out there might have some pointers....