Pile Design and Construction Practice, Fifth edition

an optional 35oleader rotation (Figure 3.3). In ‘fixed extended’arrangements, the leaders
extend above the top of the jib with a connector which allows freedom of movement.
Leaders are usually provided in top and intermediate sections about 5 and 2.5 m long jointed
together to provide the required leader height. As an alternative to spotters, simple hydraulic
telescopic rams are used to enable raking piles to be driven, with a bottom stabbing point
section bearing on the ground, levelled by hydraulic jack. BSP International Foundations
Ltd fixed extended leaders have lattice panel lengths of 7 m for the 610 mm square section
and 7.5 and 10 m for the 835 mm square section. The respective maximum lengths under
the cat-head are 22.5 and 38 m, subject to crane jib length; maximum load for pile and
hammer at a back rake of 1:12 with the 610 mm section is 12 tonne, and 21 tonne for the
835 mm section at a back rake of 1:3 using standard stays.

Piling equipment and methods 75

45 ° (with 2-point support)

4.095 m 4.29 m

Adjustable stays

Box section leader with

lateral inclination

18 °

Maximum height 26.32

m

Usable leader length with SuperRAM 6000 18.6

m

Figure 3.2Banut 650 piling rig (courtesy ABI GmbH).