[justinclift]

> It will drive itself straight into the ground and most of the rod's kinetic energy will be spent pulverizing bedrock and itself. Such a weapon would be great for taking out bunkers, but I think very wasteful for any other purpose.

Wonder if it could be precision enough for non-military applications? eg possibly faster for deep geothermal drilling than using the existing surface based borehole drilling approach.

For military applications though, it'd wonder if such a rod (or small sequence of them) could be effective when striking geological fault lines. eg the San Andreas Fault line

Aka the old "use the terrain" approach.