How I wore out my back. He thought I spent all my time walking around with a clip board. I spent a good part of my 21 years at my last employer on this same model drill rig drilling test borings. This a clip of one trip out, drilling test borings you drill 5', trip out switch to a sampler go back down drive the sampler with a 140lb hammer with a rope and cathead pull rod and go again and so on 25 or 30 time a day. Watch for the slip jaw that holds the rods during the breaking, it weighs about 8lbs and fits perfectly on the top of your foot if dropped!
https://www.youtube.com/watch?v=A11gRI4m9kE