Abstract: Apparatus for testing the load-bearing properties of piles comprises a cover which fits over the upper end of a pile as a cap. A weight slidable on guide posts extending up from the cover is releasably held in a raised position by wedges acting on a bar which is pivotally connected with the weight and extends up through a tapered opening in a transverse support extending between and supported by upper portions of the guide posts. When the weight is released by moving the wedges upwardly in the tapered opening of the support, it falls by gravity toward the pile cover and engages coil springs mounted on the cover. The springs convert the kinetic energy of the weight into potential energy and apply a reaction force through the cover to the pile for a period of time. Acceleration of the pile and of the weight are measured and recorded. The potential energy of the springs is reapplied to the weight to cause it to rebound to a height lower than its initial height where it is held by the wedges.