Pile Design and Construction Practice, Fifth edition

Piling equipment and methods 107
Figure 3.25 Watson 5000 crane attachment power auger on elevated platform on a 40 tonne
crane with 200 mm telescopic kelly for installing 2440 mm casings.
plate augers by spinning them after withdrawal from the hole and from buckets either by
spinning or through a single or double bottom opening. It is an EU mandatory safety
requirement that spoil from an auger should be removed at the lowest possible level during
extraction to ensure that debris from the flights cannot fall onto personnel or damage
machinery and to avoid rig instability. Hydraulically operated cleaners which can be rapidly
adjusted to suit CFA diameters from 400 to 2000 mm are available.
The Calweld drilling machines comprise lorry-mounted bucket drills, with either hydraulic
or mechanical drives, crane attachments and plate augers. The lorry-mounted hydraulic
bucket drills range in size from the 42 LH with a 914 mm diameter bucket capable of drilling
to about 29 m with a triple telescoping kelly or to 60 m with extensions, to the 5200 LH capable
of operating a 3650 mm bucket and reaming gear to drill shafts to depths up to 52 m with
a triple telescoping kelly. The mechanical drive models, 150C to 250C, have capabilities
ranging from 914 mm diameter at 21 m depth to 3350 mm at 26 m. The ADL and ADM auger
rigs are also lorry-mounted with rigid rotary tables producing 88 kNm torque for drilling
1800 mm diameter holes to 30 m using double telescoping kellys. Calweld crane attachment
drills range in size from the 125 CH providing 169 kNm torque to the 400 CH 540 kNm
torque all with large opening (686 mm) rotary tables. These rigs can operate with square or
round quadruple kellys 21 m long and have standard bridge frames up to 5.18 m drilling
radius. Watson produce drills for mounting on trucks, crawlers and as crane attachments
(Figures 3.25 and 3.26) capable of producing shafts up to 3650 mm diameter to depths of 41 m
also using quadruple kellys. The Casagrande RM21 mechanical rotary table crane attachment
can drill a maximum diameter of 2500 mm to a depth of 82 m using maximum torque of
220 kNm. The Soilmec RT3 and R25 rigs are crane-mounted, mechanical and hydraulic