The successful combination of Tamrock drilling rigs and Sandvik rock drilling tools ensures that UAE quarry operator Gibca Crushing is able to meet its production schedules for gabbro – considered to be the region’s toughest rock.

As the construction boom continues in Dubai and the rest of the UAE, contractors are increasingly seeking quality aggregates from local quarries, particularly for asphalt and concrete production from gabbro.
Featuring a density of 2.8 to 3 tonne/cu m and an aggregate crushing value of 13, the rock, found exclusively around Fujeirah, is highly abrasive and has a 44-50 per cent silica (SiO2) content.
Quarry operator Gibca Crushing at Kadrah, some 25 km north east of Dhaid, is just one of a number of quarries in the region to recognise the performance provided by its Sandvik Tamrock fleet of drill rigs and rock tools working in this highly abrasive and dense rock, says a spokesperson for Tamrock Sandvik Corporation in Finland.
Gibca received its first licence to recover gabbro from the local municipality 25 years ago in a riverbed retrieval application of the wadi spread over a two sq km area.
As the riverbed source dried out and the demand for the gabbro increased, Gibca opened the first of two quarries some three years ago.
With the continuing demand for increased production, a second quarry, was opened in 2001, approximately a kilometre away from the existing crushing plant.
Gibca took delivery of its Tamrock rig, a Power Trak CHA550 hydraulic, self propelled, self contained crawler-based surface drilling rig in 2000.
Designed to drill vertical holes with a diameter of 51 to 89 mm, utilising 32 mm and 38 mm diameter extension rods, the rig is powered by a Caterpillar diesel engine.In addition to the engine, the powerpack includes a clutch and gearbox which separates the power for the hydraulic gear pump and flushing air compressor.
To ensure a good daily performance in varying rock conditions, the impact energy, feed force and rotation speed of the CHA550 can be adjusted.
To keep pace with the demand for gabbro by the region’s contractors, Gibca purchased its second Tamrock, a Power Trak CHA660 rig 18 months ago.
Both rigs today each drill an average of up to 26 drill m/hr eachto ensure sufficient raw material, says a spokesman for the company.
Drilling at a 76 degree incline, the rig features Sandvik rock drilling tools with a 64 mm standard bit and MF extension rods to improve penetration rates.
Holes are drilled to depths of between 10 m – 18 m with a different drill pattern, taking an average 30 to 45 minutes-a-hole to complete in the hard-density rock.
Says  quarry manager Gulam Mohammed: “The life expectancy of the Sandvik drill bit is 2500 drill metres per bit”.
In the overburden and softer mix layers, Gibca uses its Sandvik retrac drilling bits and MF extension rods to ensure minimal hole deviation in the softer materials.
Working 20 hours daily, with two shifts over six days a week, the quarry is producing 150,000 cu m/month of aggregates and rocks for construction applications throughout the Emirates.
According to Mohammed, Sandvik Tamrock equipment is very good and provides exceptional service in difficult conditions.
“The secret is,”he adds, “we take very good care of our equipment, maintaining it correctly and regularly.”
Additional after-care back-up is also provided by the local dealer, Dynatrade.