Borehole widening backreamer - GIF

[Frank S]

I thought they typically pull a pipe or conduit in behind the reamer. If not there is a good possibility the bore will collapse after the reamer is pulled through.

If not, then they would at least have a swivel and a cable attached to the back eye on the reamer. I've recently made a few reamers and pipe pullers for a local contractor. He says you never want to leave a blank bore hole if it can at all be avoided