A new tunnelling jumbo, the DT912D, has been added to the range of products offered by breaking, drilling and crushing tools and equipment provider Sandvik Construction and is equipped with the company’s RD525 hydraulic rock drill, or optionally the RD520.

The DT912D, designed specifically for limestone applications, is a self-contained, air-mist flushing, diesel-hydraulic high-reach, single-boom jumbo that offers high-quality drilling in its most advanced form.

Featuring a RD525 rock drill for “superior drilling performance” with high lifetime, as well as the most powerful engine ever installed on a diesel-hydraulic jumbo, the Cummins Tier 4 Final with 205 kW, the machine can bring a true boost to productivity with low fuel consumption, explains Sandvik.

The Sandvik RD525 and RD520 are low-profile, hydraulic percussive rock drills. With high frequency and a patented stabiliser equipped with an intelligent control system dampening harmful shockwaves, these drills are “bound to boost your performance”, says Sandvik.

“Offering almost 17% higher penetration rates and significantly longer tool life, the robust and reliable drills make face drilling, as well as bolt hole, exploration and injection hole drilling, way more profitable than before.”

The rock drills offer 40% longer tool life for the shank and 17% for the bits, compared with the HLX 5 rock drill in test conditions. Results are subject to rock conditions and drilling parameters.
The simple body structure of the drills, along with their modular construction and visual wear indicators, guarantee ease of use and maintenance. “Built to last, the robust and reliable drills feature only a few pressurised seams between functional modules,” adds Sandvik.

Power is – of course – of utmost importance when it comes to drilling, says the company, explaining that the RD525 supplies 25 kW, and the RD520 20 kW.

The RD5 series drills are also available as retrofits. They can be assembled to all Sandvik jumbos (DTi and DT, Tamrock Axera), with THC, TDATA or iDATA control systems delivered after 2000.

The retrofit kit includes a rock drill, carriage assembly, feed wire, an intelligent control system for the stabiliser and required changes to the rig control system.

Sandvik states that the DT912D tunnelling jumbo is completely self-contained.

The DT912D is powered by a fuel-efficient and environment-friendly Tier 4 Final diesel engine and equipped with an onboard compressor and water tank for air-mist flushing. The “new intelligent, state-of-the-art control system” enables increased productivity in both tunnelling and underground mine production applications, notes Sandvik.

The jumbo is designed for fast and accurate drifting and production drilling of 12 m² to 125 m² cross sections; the 24 t jumbo combines Sandvik’s “novel technology, creativity and expertise with the vast experience gained over the decades in the business”, highlights the company, adding that the DT912D is an optimal machine for multifaceted operations that will take excavation efficiency to another level.

As standard, the jumbo has an electric-controlled drilling system with added automatic functions, including one-hole automatics, and is equipped with a SB150 universal boom for large, optimally shaped coverage and full automatic parallelism. In addition to face drilling, the boom can also be used for crosscutting, bolt-hole drilling and extension drilling.

An efficient 4 m³ onboard compressor and an extra-large 1 000 ∙ water tank for air-mist flushing allow the DT912D to operate independently from the tunnel or mine infrastructure and guarantee a longer drilling period from one setup. Sandvik suggests that this enhances the efficiency of the cycle time and provides extra flexibility of use.

The company says the DT912D offers rapid, safe and balanced tramming, owing to its powerful, four-wheel-drive-centre articulated carrier. The ergonomically designed cabin complies with the standards of the falling object protective structures and roll-over protective structures, and is well insulated to reduce noise and vibration.

The noise level, Sandvik boasts, remains under 73 db at all times, adding that the cabin is also available with a cabin lifting system allowing better visibility for tramming and drilling. This improves ease of use for the operator, while the well-proven Sandvik intelligent control system architecture with comprehensive built-in diagnostics and user-friendly controls ensures easy maintenance.

To ensure the best performance, different instrumentation levels can be chosen at any time on the DT912D, enabling the most-effective performance in accordance with the user’s specific needs.