For their test firing, the researchers used a hydraulic ram to drive the cylinder into a preheated engine. The Economist, “A rocket that devours itself,”.Bouwes combed the internet and found a thriftier alternative a hydraulic post pounder, a machine that resembles a cross between a jackhammer and a bazooka. ben goldfarb, Science | AAAS, “Beaver dams without beavers?.We are currently experiencing intermittent Comcast phone services. You can still place orders online and we will process it. If you still need furtheristance, please or ..Jackhammers Paving Breakers Choosing a Paving Breaker Jackhammer Paving Breakers are T handled tools made to run verti.y and break up rock and concrete or cut asphalt..