UAE quarry operators Al Futtaim Tarmac have taken delivery of two Tamrock Ranger 700 Rock Pilot drill rigs equipped with Sandvik rock tools for use at their recently opened Shawkah Quarry in Ras Al Khaimah.
The quarry covers an area of 8km2 with initial reserves of around 50 million tonnes and additional extended reserves of 300 million tonnes. Some of the region’s toughest rocks with a density of 2.9 tonnes/m3 can be found here, including a tough, highly abrasive gabbro, which is in constant demand in the UAE.
Having initially subcontracted all drilling work at the quarry, Al Futtaim Tarmac are now undertaking all drilling activities in house. ‘The decision to take over drilling and just contract out the blasting was taken to improve efficiency and reduce operating costs,’ explained quarry manager Danny Bidgood.
‘We obviously knew the reputation of the Tamrock rigs from previous experience, and with the rigs held in stock by local dealer Dynatrade, we were able to start drilling duties virtually straight away.’
The robust build of the Ranger 700, which has been designed for production drilling in medium-sized quarries, is well suited to the demanding terrain of Shawkah Quarry. The rig is equipped with an HL 710 hydraulic rock drill, chain feeds, rod-handling system, telescopic-boom and power pack, all mounted on an oscillatory F16-type undercarriage.
The crosswise-mounted power pack and hydraulic pumps are located at the rear of the rig to balance the weight of the boom, feed and rock drill. This minimizes the load on the drill and ensures good stability.
The Ranger 700 also includes the Rock Pilot drilling control system, which automatically adjusts the drill power when reacting to changing rock formations and hardness.
The quarry operates a double 10h shift six days a week, but the drill rigs have the capacity to meet production demand on a single shift, drilling on average 12 holes up to 14m in depth. Drilling takes up to 45min per hole due to the rock’s hardness.
To maximize economy, penetration rates and drilling capacity, the rigs are fitted with T51 rods and Sandvik Capp black label drill bits, with bit regrinding carried out on site when necessary. Generally, the bits achieve 300 drill metres when new and 200m after each subsequent regrinding, which is usually carried out twice.
‘We’re currently drilling approximately 8,000m per month and blasting five or six times a month,’ said Mr Bidgood. ‘In two years, it will be a completely different looking quarry with more established benches, extensive landscaping and tree planting along the quarry approach.’