Wondering if anyone has made a vice or clamp mounted on a surface to allow one person to do chisel work. Was thinking of thick plate steel or heavy h-beam with a clamp or vice attached. This way a piece could be clamped down and worked on with a chisel. 

There are all manner of clamping used to hold metal. There is a ramp used in a vise to angle the  metal so it is easier to work on. 

It all depends on your project and what you have available to clamp with and clamp on to.