Causeway Geotech Limited, one of the leading independent ground investigation contractors in Ireland and the UK, have recently taken delivery of their first dual purpose rota-sonic drilling rig from Eijelkamp Fraste. The Eijelkamp Fraste CRS XL 140 Duo unit which Causeway Geotech took delivery of from the manufacturer in March 2021 is the first rig of its kind on the island of Ireland and represents a massive leap forward in drilling technology in the country.
Sonic drilling is a cased overburden system which operates on the principle of high frequency (150Hz) vibratory actions on the drill string that reduce friction and enable rapid advancement of the sampling tools through strata. Production rates are typically significantly quicker, and sample return and quality often much higher, than traditional drilling methods, such as cable percussion boring or rotary percussion drilling. The system has also been proven to be the optimal method for drilling through challenging ground conditions where old technologies struggle, such as dense granular materials, cobbles and boulders, heavy made ground and landfill material.
The dual purpose rig purchased by Causeway Geotech is a versatile unit which allows for the construction of high quality boreholes to depth in soil and rock strata using a single set-up. Conscious of the benefits of Geobor S rotary core samples, as used throughout the rest of their fleet of traditional rotary drilling rigs, Causeway have elected to tool up the rig for drilling through overburden in large diameter to allow for Geobor S rotary coring follow-on in boulder clays and rock.
The rig is also fitted with a Manipall 200 casing and rod handler. This system reduces the manual handling element of drilling operations by using a specialist electro-magnetic extension arm for lifting the heavy and cumbersome drilling rods and casing. The benefits of this are reduced risk of accidents and fatigue of the drilling operatives, while improving efficiency of the drilling process.
While there is a common perception in the industry that sonic drilling is an expensive option, the single set-up afforded by the dual purpose rig coupled with the higher production rates over conventional methods means that, quite often, sonic drilling is often actually a cheaper method of investigation.
Speaking about the acquirement, Causeway Geotech’s Operations Director, Darren O’Mahony said: “while this has been a significant investment for our company, it represents a significant advancement for the ground investigation industry in Ireland. Historically, any sonic drilling carried out in Ireland involved bringing specialist subcontractors across from the UK, which carried with it a significant cost which was often seen as prohibitive to Client budgets. By having this technology based on the island of Ireland, it now affords consultant engineers the opportunity to incorporate modern, safe drilling methods, often best suited to their requirements, into their work scopes and within the Client’s budget”.
The rig has already commenced work on its first commission for the Metrolink GI Contract in Dublin, after which it is scheduled to be deployed to a high profile highways investigation.