US patent 20190085688 A1 tunneling with plasmaAll you wanted to know about how the tunneling with plasma torches is supposed to work: the machinery, productivity, process, etc.
There is much more to this than a simple torch ,elting/vapourizing rock.
IMHO we are a long way from seeing an operating machine. The problems will not be with the torch. Making the whole thing work will require a great effort, but if it can be made to work it will be fantastic. Another Elon Musk show. Just hope it works in my life time.