Drill & Blast

Complete package rig exceeds expectations

Donnelly Blasting Services (DBS) is headquartered in Jimboomba, in southeast Queensland. The Australianowned, family-run business conducts work in numerous quarries and construction and dam projects in southeast Queensland and northern New South Wales, with about 80 per cent of its clients being quarries.

The company offers the full rock on ground service. To quote Dan Donnelly, “we do everything in-house – the surveying, markout, boretrack design, shotfiring, monitoring, and drilling”.

His father and company founder Jason added: “We float our rigs, mark our own holes, survey, drill our own holes, load the fire, do all the reporting, all the surveying and all the blast monitoring ourselves. For our explosives, we use Orica as a contractor but we also have our own explosives trucks.”

Jason started the business 20 years ago after he spent 10 years as a shotfirer for Orica Mining Services. He wanted to pursue a career as a part-time contract shotfirer but ultimately formed a business that today employs 30 staff, including around 20 drill operators, and keeps him busy full-time.

DBS has a modern fleet of Epiroc smart rigs and specialised rigs that can be configured for special project requirements. Added to that are mobile manufacturing units (or ANFO trucks) with augering and blowloading capabilities, a 25-tonne excavator with rock breaker and a 30-tonne widening tri-axle low loader.

Jason said the company has built its reputation on flexibility, which is “we’re able to do what the customer wants”.

“We have GPS guidance on our rig – a lot of the larger rock on ground services don’t have that,” he said. “We can control the whole outcome because we do the whole job. We put the extra holes in, we control the drilling [with machine guidance] – we understand what’s going on with the drilling. We have the latest technologies in the drills, so we’re saving our customers money. Some other companies can use up to 400 or 500 litres of fuel a day – we’re down to below 200. We work with our customers for a better outcome.”

DBS’s association with drill rig manufacturer and supplier Epiroc covers nearly the whole lifetime of the business.

“We started with Ingersoll-Rand, which was bought by Atlas Copco,” Jason recalled. “It’s been a long association but we’ve probably used Atlas Copco [now Epiroc] for 15 years. We ended up changing to them from another brand for the technology, fuel burn, operator comfort, reliability and product support.”



Sound of silence

DBS’s 20-strong Epiroc/Atlas Copco drill rig fleet comprises manual-operated PowerROC T35s, as well as numerous smart rigs that operate via machine guidance including ROC D7Cs, ROC D9Cs, and up to six SmartROC T40 rigs. The contractor has also recently taken delivery of some SmartROC C50 COPROD rigs. Some of the DBS rigs are also equipped with sound suppression for environmental drilling restraints (eg noise pollution), reducing the noise factor by about 10 decibels.

“I can be 20 metres away from it and I can pick up my phone and ring you and you’d hear background noise, and that’s all,” Jason said. “The silenced kit takes the ringing, the high frequency out of it – it reduces that steel on steel sound.”

“It doesn’t echo down the valley like a traditional drill rig would,” Dan added.

One of these sound-suppressed (or silenced kit rigs) – a ROC D9C – has been working at Fulton Hogan’s Stonemaster Quarry, on the Gold Coast, on an integrated program devised by Cement and Aggregate Consulting Services (CemAgg) to raise the quarry’s productivity by as much as 20 per cent.

DBS has successfully collaborated with CemAgg and Fulton Hogan on a program comprising drone surveillance, quarry design, machine control and site-based GPS surveying to extract Stonemaster Quarry’s remaining reserves. An in-depth explanation of this service has been explained in a previous issue of Quarry.

The second silenced kit rig – a SmartROC T40 – has been recently working on a greenstone deposit at Fulton Hogan’s Blue Rock Quarry, at Cedar Creek, also in southeast Queensland. According to CemAgg, Blue Rock has a more challenging geology than Stonemaster Quarry, coupled with new development works that require careful planning so that future production is not constrained by limited supply of higher raw grade feed.2

The SmartROC T40 is equipped for hole diameters in the 76-127mm range, with maximum hydraulic pressure of 220 bar and a maximum impact rate of 44 to 53 Hz. It features a folding boom system, aluminium profile feed beam, hydraulic cylinder feed beam and a carousel-type rod handling system, with 1 + 7 rods.

The 15-tonne unit is powered by a 168kW, turbo-charged Tier 3 or Tier 4 Caterpillar C7.1 ACERT engine at 2200 revolutions per minute and features an Atlas Copco OIS K-36-C111 GD screw compressor, with a maximum working pressure of 10.5 bar and free air delivery of 153 litres per second. The engine and compressor speed is self-adjusting, according to demand. Three variable hydraulic pumps lower engine speed during non-drilling periods and tramming. Automatic cooler and dust fan controls are standard.



Best results

Epiroc’s optional machine guidance systems on the T40 comprise the Measure While Drilling (MWD), Hole Navigation System (HNS) and ROC Manager software. The HNS in particular manages hole position, inclination, correct aiming and the required hole length (as defined in the prepared drill plan) via the global navigation satellite system (GNSS). As a result, it can decrease the drill and blast cost per every cubic metre produced.

“We utilise site navigation, so the driller can walk in and utilise the boom as much as possible,” Dan said. “The machine’s not moving the carrier, it’s moving the boom to the next hole. And with the navigation, we can use the automatic set-up, which means we can get great accuracy.”

It was at Blue Rock Quarry that the silenced kit T40 recorded some of the best results in relation to penetration and fuel usage. Daniel Kirwan, Epiroc’s regional manager for the Brisbane and Mackay regions of Queensland, remotely monitored the performance of the rig and according to that data, the T40 drilled 487m in one shift (of around 11 to 12 hours’ duration) at total drill power and capacity, burning through just 187 litres of fuel – exceeding regular performance expectations.

“It’s a pretty good record – to do that many metres in day,” Kirwan explained. “When you start looking at the fuel usage, it pretty much works out as 0.4 litres per metre drilled, which is really good. Normally, the T40s will burn through 0.5 or 0.6 litres per metre. That equates to around 15 litres per hour.”



“It far exceeded our expectations,” Jason said. “Years ago, if we got 200 metres a day, that was a good day on the previous drill and you would burn 400 litres of diesel. This is how far technology has taken us in such a short period of time.”

“It was amazing,” Dan added, “since the industry average is a litre per metre – the rule of thumb – and there are a lot of machines that are well over a litre per metre.”

Kirwan attributed Epiroc’s 64-127mm T51 speed rods at a 3.6m length as a major factor in the metres per litre drilled.

“By having our rod, [DBS was] able to up the impact pressure on the rock drill,” he explained. “Essentially, they’ve been able to increase the impact rate on the drifter to get more metres. And to do that you need to have drill strength capable of standing up to the increased pressure.

“With our shanks and rods there wasn’t breakage and because of the rod quality they could run the drill harder, whereas lesser quality rods would break when you put that much pressure up. So that was definitely a big part of it – being able to increase the performance of the rock drill and have the driller consumables to match it.”

Kirwan said it was a testament of Epiroc’s history and expertise. “Epiroc’s been making rods for the best part of 100 years. It manufactures premium rods at a premium price. What we have is probably the longest lasting, highest quality rod.”

All the parties agree that for these results to be replicated by another rig in another quarry setting, there needs to be a combination of factors.

“As the operator was getting more comfortable with the rig and winding more power into it,” Jason said, “we could see the metres going up and up. That was the thing that was really great about his performance on that shot, it was a good designed shot, good bench preparation, all the stars aligned on it.”

“It’s an example of a customer that’s using all the features of the Epiroc machine,” Kirwan said. “Some customers may just buy the rig for the fuel savings or may just take a silencer kit. But DBS has purchased the whole lot: the silencer kit, the HNS and the fuel burn all working together with the rod package. They’re using the whole Epiroc package to get the best results.”



At the leading edge

DBS and Epiroc have reported positive feedback about the performance of the smart rigs. Jason Donnelly said that quarry operators were genuinely surprised by the drilling results.

“When we take the T40 into a quarry, the quarry manager comes around and asks, ‘How many metres did you do today?’ And the operator will say, ‘150, 170’. The manager will go ‘Really?’ and then they’ll go back and check the fuel book and they come back and confirm the next day that it wasn’t a one-off. And they’re like, ‘Wow! I’m glad we’ve got this now!’ They realise that, compared to other drill rigs, 160 metres drilled in a day represents a lot of savings!”

“The bulk of the customers using the T40 are drilling a 89mm hole size and it seems to be the drill of choice, particularly when it comes to penetration rate, fuel burn and then having the technology options on it,” Daniel Kirwan said. “It’s also sort of future-proofed for changes if quarries want to go down the hole navigation path.

“There’s a bigger emphasis in the industry on technology, reducing your fuel burn and having all capabilities built into the machine, so if you go to a site where they want to invest in using hole navigation, you have that capability.

“It comes down to your hole size and capacity, and what you actually want to drill,” Kirwan continued. “The Donnelly guys have set up the T40 and now they’re almost going beyond that to the C50 COPROD to do bigger hole sizes, the 102-115mm holes. If you’re doing the 89-102mm hole size and want to reduce your fuel bill, and potentially look at ways of getting technology into your business, the T40 is definitely a machine to consider.

“We’ve had a lot of success with the T40 on that smaller hole size (89-102mm). We have some newer products like the T45 and the C50, which are the ‘big brothers’ of the T40. Donnelly’s are starting to use some of those machines at the Hanson quarry at Wolffdene to great effect. They are at the leading edge of picking up new technology, trialling new things, which is really good for the market – to challenge the status quo.”

The T40’s positive results at Blue Rock Quarry have prompted DBS to replace the D9C rig with another sound-suppressed T40 at Stonemaster Quarry. The company is gradually replacing the ageing parts of its drill fleet with the smart rigs for its quarry assignments, and its older, more manually operated rigs (such as the PowerROC T35) are being assigned to construction jobs where the need for survey control and estimates has already been determined.

Working with CemAgg and Fulton Hogan on the integrated program at Stonemaster Quarry has also resulted in better machine utilisation for DBS across the board. “The way we conduct our rock on ground is the same but our design is completely different,” Jason said. “We have a path that we take that’s aligned more to pit design. We have a roadmap, we know where we’re headed.”

“We can plan all our maintenance better, we plan our blasting dates further in advance, and we’re not reacting to things in the quarry,” Dan Donnelly added.

Reference & further reading

1 Franklin S. The digital quarry: An integrated technical approach. Quarry 26(8); August 2018: 24- 29. 
2 Ibid.

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