Large diameter (LD) drilling either vertical piling or horizontal directional drilling is used in
construction, utilities, telecoms & underground services. Historically LD vertical drilling
systems have utilised pneumatic hammers up to 24” diameter & solid steel drilling bits which
have advanced more recently to concentric drill bits, mechanical expansion segmental bits &
overburden drilling systems used for hole expansion used for cased holes in construction
piling. With ever increasing sizes of construction being undertaken from high rise buildings in
Hong Kong, bridges & ports in Malaysia to wind turbines both onshore & offshore, the use of
LD piling up to 1400mm & beyond is becoming more commonplace. LD canister drills or
cluster hammers have been developed over the last decade in an attempt to improve the
penetration rates when cutting LD piles through medium to hard rock formations. The concept
of cluster drilling or canister drilling involves between four & nine smaller individual
pneumatic hammers that are held together on a bolster or canister to provide the combined
force both impact & rotational action to cut through varying rock (medium density formations
such as gravel, clay & boulders & hard rock) formations. These systems have been found to
be unreliable due to imbalance & stresses causing catastrophic failure & breakdown of
individual hammers which are frequently experienced down the hole. Bulroc have 40 years
experience in novel pneumatic hammer & drill bit design in both horizontal & vertical
applications. The proposed LD hammer 33” & LD drill bit technology aims to be able to
operate in both vertical & horizontal environments producing holes from 1250mm to 1400mm
diameter from a single system in both medium & hard rock formations. Global piling
equipment machines market was valued at US$4.31B in 2014 expanding to US$6.94B by
2022. (Grand View Research 2014 – Piling Machine Market Analysis).