Abstract: A cap formed of cast steel is permanently attached to the top end of a tubular metal caisson to facilitate the handling of the caisson and its installation with a sonic or vibratory driver/extractor mechanism. The cap has an annular base formed with a relatively large central opening. A plurality of bolt-receiving holes are formed in the base and are spaced in an arrangement for subsequent mounting of a superstructure on the caisson. A pair of diametrically spaced clamping plates is formed integrally with the base for cooperative engagement with the vibratory mechanism. A pair of diametrically spaced lifting lugs are mounted on the base between the clamping plates to facilitate the handling of the cap and caisson. The clamping plates each have a straight chordlike center section and may have a pair of end sections. The cap has a size slightly larger than the size of the caisson top end and is secured thereon by one or more welds.