Every blow of a diesel pile hammer is a single stroke of a two-stroke engine in which the pile itself acts as the crankshaft. The machine is simple in structure: a vertical steel cylinder, a heavy free-falling ram acting as the piston, and an anvil or impact block seated on the pile head. There is no flywheel, no connecting rod and no external power supply once it is running. The cycle is self-sustaining: - The ram is lifted by a trip mechanism on the crane and released - As it falls, it closes the exhaust ports and compresses the trapped air - Fuel is injected onto the impact block just before contact - The ram strikes the anvil, driving the pile and atomising the fuel into the hot, compressed air - The mixture ignites, adding a second push to the pile and launching the ram upward - The exhaust ports reopen, spent gas escapes and fresh air is drawn in - Gravity returns the ram and the cycle repeats, typically 35 to 60 blows per minute Delmag, based in Esslingen, Germany, brought th...