As part of the design of an important pile foundation, an extensive testing program has been carried out in order to determine the type and the necessary characteristics of the pile best suited to the site and the structure to be designed. Three types of piles have been tested, i.e. timber piles, a steel H-pile, and a Herkules precast concrete pile. The Herkules and H-piles were equipped with deformation gauges and driven in 10-ft (3-m) increments to a total length of 70 ft (21 m), a loading test being carried out at the end of each increment. Thus, it was possible to determine the variations of the bearing capacity, the point–resistance, and the skin-friction as functions of the embedded pile length.The aim of this paper is to present the technique used and the results obtained.