So called because to charge the cylinder you had to stand in the cut-outs in the body and jump up and down before tripping the magneto and causing the huge cylinder to fire. The Irish construction workers were so adept at this, and with the rammer being so cumbersome, they could 'ride' the rammer across the site to the trench by remaining stood in the side cut-outs! As a young plant mechanic, I was amazed to actually see this skill in action - Truly, paddy's bike!
by yorkshireman June 23, 2010