Site visit: Cat kit at Doha Quarry in Fujairah

PMV heads to Doha Quarry in Fujairah with Caterpillar dealer Al Bahar to witness the application of both the machines and the Cat Product Link system

Site Visits

Qatar currently has a deep thirst for quality aggregates, and in few places is this more apparent than in emirate of Fujairah, where the namesake Doha Quarry is churning out crushed and sized gabbro aggregates for the peninsula’s thirsty infrastructure projects.

Gabbro, a mineral similar to basalt, or a mineral like it is required on most projects as a component of asphalt or concrete, and as Raed Limoun, general manager at the quarry, notes, the Al Hayl area in Fujairah produces the best material in the GCC.

The only drawback of the area is that it is too far from the major hubs of construction activities within the UAE to deliver the material within the country at a cost-effective rate.

“Here, we cannot competitively deliver our material to Dubai, but we are close to the port, so instead we deliver our material to Qatar and Kuwait,” says Limoun.

As luck would have it, a collusion of circumstance and regulation has rendered Qatar quite desperate for quality aggregates.

“The whole country is undergoing construction, and the existing ground material is not suitable for any construction,” explains Limoun, before highlighting that, “Qatar actually stopped all blasting and quarrying for limestone in 2003 — now they are only using the existing ground material after excavation for specific projects or for local purposes.”

Limoun notes that in 2000 Qatar had a population of a mere 600,000 people; whereas now the population stands in excess of two million — most of them are in Doha, and all of them requiring utilties and infrastructure and plenty of gabbro-laced asphalt and concrete.

“So more than 90% of what Qatar requires is coming from this area — it is like a dream,” Limoun enthuses.

“From here we are sending bulk quantities of between 45,000t up to 90,000t by vessel.

“We are making $5m just here in this quarry, — actually $6m, because there is $1m of scalping material that we are not considering. It is zero to two inches, which we are not exporting as product; but it is still being using locally under as a base layer or as filler material.

“Kuwait is taking more of the lighter gabbro material (found in the Masafi area) than the heavier gabbro material, depending on the project specification and requirement.”

The quarry operation itself runs almost exclusively on Caterpillar equipment provided by Mohamed Abdulrahman Al-Bahar, the OEMs authorised dealer and aftersales partner in the UAE and across every other GCC country, with the exception of Saudi Arabia.

Doha Quarry has six excavators, of between 45t and 75t, seven 40t dump trucks and six wheel loaders: 3x966, 2x982s and 1x988, as well as two crushing and screening lines.

But the first step is the blasting: a process planned by mining engineers and carried out by third parties operating with under the supervision of the local civil defence.

The explosive must also be ordered a month in advance, so respectively, Limoun plans for the quantity of material that he will need to produce at the beginning of each month.

“The maximum blasting capacity allowed in the UAE is 9.5t of explosive material, which can yield 85t-90t of raw material. So one tonne of explosive can release 8,000t of material (or 350g of explosive for one cubic metre),” details Limoun, pointing to the most recent blast face, where 7.5t of explosive (across 170 drill holes drilled two to three metres deep) was used to release 65,000t of material.

He explains: “10% of this material we call armour and under-layer; 85%, weighing from zero to two tonnes we are loading by excavator into the dumpers to take to the feeder. From this primary material we are removing everything from 0-50mm — the scalping material — for use in road projects locally, but not for export, because equivalent material is available in Qatar.”

Scalping is a process aimed at removing sediment contamination early in the process. Small material picked up by the excavators is covered in dirt that slows down the crushing and screening process. This allows the clean stone to be crushed without fear of blockage.

Limoun continues: “We are then sending everything from two inches to eight inches to the secondary section. For gabbro processing there are five stages. Our target diameters are 20mm, 10mm and 5mm, for use in concrete and asphalt. To achieve this, you need four stages of crushing and screening.”

At any given time, the operation requires two main excavators to work on the quarry face, while a third excavator is used with a grabbing attachment to load the irregular 2t to 5t chunks of ‘armour’ that is produced from the collapse of the external face of the quarry wall during blasting onto flatbed trailers. This material is currently being sold to the Ghantoot Group to reinforce the Kalba corniche.

Gary Martin, system application manager at Caterpillar SARL in Jebel Ali, chips in: “They’ll typically use excavators because they can be more selective in the material. When you use a wheel loader it is a lot more difficult to dig the armour out, or to dig around the armour and put it to one side; with an excavator it’s much easier — and you’ll find that trend with most of the quarries around here.”

A fourth excavator is equipped with a hammer to reduce some of the rocks, while the remaining excavators wait in reserve.

Doha Quarry has also now been employing the US manufacturer’s proprietary telematics system Cat Product Link and the accompanying remote monitoring platform Vision Link, for the past two years, resulting in both a boost to production and the lowering of costs.

Limoun notes: “First you know whether your machine is working or not. Sometimes, we receive notes when the dump truck operators are returning from the feeder empty in neutral — resulting in overloading. Now they know that somebody is watching. Second, any abnormal occurrences, like overheating are flagged, and our supervisor in the workshop quickly picks up on it.”

The latter point is key, because it also helps Doha Quarry to schedule preventative maintenance and avoid the risk of vehicle faults or breakdown.

There are few scenarios where this is more critical than a quarry, where the profitability on the entire operation relies on the consistent flow of raw material to the feeder. With an optimised maintenance schedule informed by both Product Link and the dealer, problems are caught early, while the accurate analysis of any faults ensures that only the correct, damaged components are replaced.

“Having Cat Product Link has had a big impact, even changing the mentality of the workshop,” highlights Limoun.

“Breakdowns are fewer, fuel and spare parts consumption is down, and productivity is up.

“From 2004-2008, we could not even handle 180,000 tonnes in a month in the 250 product; now we are talking about 500,000 tonnes with almost the same machinery.

“We only increased the fleet by one excavator, the 374F, and retired a 345 for a 349.”

Correct maintenance has been particularly critical to the operation of the dump trucks, which experience the most load and stress on their components out of all the pieces of equipment in the quarry. Previously, Doha Quarry carried out all of the maintenance on the dump trucks, including work on the engines and powertrains, in its own on-site workshop. Now they are sent to Al Bahar for important repairs.

“We previously performed our own engine overhauls and so many times, we would carry out an engine overhaul on a dump truck, use it and then have failure in the engine. We never touched 5,000 working hours with the dump trucks. Now we are overhauling the engines after 8,000 working hours,” notes Limoun.

“The common thing is that many managers want to handle everything within their quarry, but this is wrong. Their mentality is that if they send their machines to the dealer for maintenance it will cost them, but we have been maintaining our machines in the right way for three years. Before we could never run our dumpers for 22 hours; now it is 24 hours.”

With the excavators, Limoun asserts: “I doubt anyone is making 5,000 hours if they are making the overhauls in their own workshops — and you will pay almost $80,000 and have to repeat the job after one year. Since I started working with Al Bahar, I only had to take out the engine on the 365 after 35,000 hours.”

Through the Cat Vision Link system, Al Bahar is even able to predict the spare parts requirements of Doha Quarry’s fleet and double check parts orders before they are sent out — guarding against human error.

Limoun notes: “Sometimes we order the parts online and Al Bahar correct our orders. Years ago they would send the parts and we would have to send them back — now sometimes they send the order back before they issue the parts, and say, ‘kindly check again’ — which is saving time and money.”

Limoun reports that a few days before PMV visited the site, he received a notification about one of his 988 wheel loaders, informing him that there was a problem in the engine.

Martin notes: “We found out that there was a problem with the injector through Cat Vision Link. In the old days, the operator might just continue operating the machine and in the end if the injector snaps off, you’re talking about a complete rebuild. The machine would be down for eight weeks and have to go to the dealership — so you’re talking about the loss of a machine, transportation costs and a very expensive rebuild. But by having the equipment monitored through Al Bahar, they’ve been able to identify the problem, and within a couple of days they’ll get the injector, and the machine will be up and running again. It saves the company a lot of money, a lot of losses and lot of downtime — it’s a really strong tool.”

The close partnership between Al Bahar and Doha Quarry recently yielded another added benefit. When the Caterpillar 374F excavator was in the process of being released to the market, Al Bahar deliver one unit to Doha Quarry for Limoun to trial it for six months. It turned out the larger bucket filled the dump trucks that much faster that the volume could be shifted in fewer runs.

He notes: “The difference was in the diesel consumption. Instead of using three dumpers, we use two dumpers and the volume of fuel reduction that we achieved was almost equal to $19,000 a month, which in 24 months is the machine price – so actually, it was free.”

Clearly Limoun has much to be thankful for, and with the Qatar market ever buoyant, Doha Quarry can continue to churn out its product. Plans for the expansion of Fujairah should just add to the business that the company is enjoying, and the site still has 70 million metric tonnes of material to go.

Most popular


CW Oman Awards 2020: Meet the winners
A round of the thirteen winning names at the Construction Week Oman Awards 2020 that


Leaders UAE 2020: Building a sustainable, 'resilient' infra
AESG’s Phillipa Grant, Burohappold’s Farah Naz, and Samana's Imran Farooq on a sustainable built environment
CW In Focus | Inside the Leaders in KSA Awards 2019 in Riyadh
Meet the winners in all 10 categories and learn more about Vision 2030 in this

Latest Issue

Construction Week - Issue 767
Sep 01, 2020