104 Piling equipment and methods
3.2 Equipment for installing driven and cast-in-place piles
The rigs used to install driven and cast-in-place piles are similar in most respects to the types
described in Sections 3.1.1 to 3.1.3 but the firms who install proprietary types of pile usu-
ally make modifications to the rigs to suit their particular systems. The piling tubes are of
heavy section, designed to be driven from the top by drop, single-acting, or diesel hammers,
but the original Franki piles (Figure 3.23 and Section 2.3.2) are driven by an internal drop
hammer. The leaders of the piling frames are often adapted to accommodate guides for a
concreting skip (Figure 3.24).
Steel cased piles designed to be filled with concrete are driven more effectively by a hammer
operating on the top, than by an internal drop hammer acting on a plug of concrete at the base.
Figure 3.23Franki pile-driving rig.