McKeon Stone was established in 1950 by Jimmy McKeon who had worked at Shorts Quarry in Stradbally, Co Laois, up until the time when he went out on his own.Jimmy initially started making Celtic crosses but Shorts Quarry would not sell him stone, which forced him to look elsewhere for material. Jimmy eventually settled on a 22ac site in Threecastles, Co Kilkenny, where the quarry is still located. Today, the stone is extracted and either processed on site before being exported or, alternatively, it is sent to the company’s other site in Stradbally for further processing into exterior building products such as stone columns or window sills, for example.
McKeon Stone was established in 1950 by Jimmy McKeon who had worked at Shorts Quarry in Stradbally, Co Laois, up until the time when he went out on his own.
Jimmy initially started making Celtic crosses but Shorts Quarry would not sell him stone, which forced him to look elsewhere for material. Jimmy eventually settled on a 22ac site in Threecastles, Co Kilkenny, where the quarry is still located. Today, the stone is extracted and either processed on site before being exported or, alternatively, it is sent to the company’s other site in Stradbally for further processing into exterior building products such as stone columns or window sills, for example.
Since 1950, the company has grown considerably to employ 47 staff between both sites, which have a combined experience of over 600 years between them. The staff are all long-serving members with three men serving 40 years each in the quarry.
Managing director Niall Kavanagh tells me about how things have changed since the start of the business. “In the early 90s, the Belgian market opened up for export of our stone. This was due to an increased demand which their own quarries couldn’t satisfy. Up to 2008, 5% of our products were exported but, due to the recession here in Ireland, this rose to 40% export in 2009 and, today, about 70% of our products are exported to Belgium, Holland and Germany mainly”.
Niall says that only 20% of what they extract is used due to cracks or flaws in the stone. They need good dimensional stone to process into building products. This leads to 80% of the stone going for crushing and processing for other uses.
Today, McKeon Stone is the only Irish-owned dimensional stone quarry left in the country as the others have been bought over by a Belgian company during the recession.
Process
Every week, the quarry will cut a 1,000t “pillar” or wall of stone from the quarry face in one single piece. This is done with wire saws fitted with diamond wire, which Niall says is a huge advance in technology when compared with the older system, although it still takes two to three days. Once the wall is cut, it is toppled over where it breaks into smaller 100t blocks.
These blocks are then further cut into more manageable sizes before being taken to the factory for processing.
The machinery
Handling such weights calls for some serious machines such as two 51t 541hp Caterpillar 988 loading shovels and two Caterpillar 245 63.5t excavators.
Most impressive of all is the newest addition to the fleet, the Hitachi 670 LCR excavator, which they took delivery of in September.
The purpose of this machine is to topple the 1,000t pillars from the top of the quarry with a ripper attachment, as well as moving the large blocks and waste around the site.
Commenting on the decision to buy Hitachi, Niall says: “We had a 50t Hitachi on hire three years ago and were very impressed by its performance and reliability.
‘‘We went to the Hilltop Quarry Exhibition in June this year to see what was available on the market and it just happened that this very machine was on demo at the event and, more importantly, was available.
‘‘We talked to the guys in Hitachi UK and our Irish dealer McSharry Bros and done the deal within the next six to eight weeks after the show.”
With a retail price of over half a million plus Vat, it certainly was not a decision that was made lightly but Hitachi’s own finance department Hitachi Capital was more than willing to do business and only required a 5% deposit with no directors’ guarantees, which was a big advantage compared with other lending institutions. Within the timeframe of finalising the deal, the Brexit referendum took place which in turn saved McKeon Stone a further €80,000 with the change in exchange rate.
Engine
Powering this mountain is a 418hp six-cylinder Isuzu engine that is both turbocharged and intercooled. This engine produces 1621 Nm of torque and incorporates an electronic-controlled fuel injection system and exhaust gas recirculation (EGR) where the exhaust gas is partially mixed with intake air to lower the combustion temperature to help reduce the nitrous oxide (NOx) levels and particulate matter (PM), as well as improving fuel efficiency. Hitachi claims that this new system will reduce fuel consumption by 6% over the previous model and 10% when working in ECO mode. McKeon Stone has reported a fuel saving of 50%, although the previous excavator was a 1990 Caterpillar 245 which would not be up to today’s standards. The fuel tank capacity has also increased to 920 litres from the previous 740.
Hydraulics
Turning engine power into movement is the job of the hydraulic system, which on this machine consists of two variable displacement main pumps that produce 443l/min each, as well as a pilot pump with a flow of 50l/min. These pumps send oil to four axial piston motors, two of which are responsible for the movement of the tracks, while the other two look after the swing of the machine.
Hitachi claims that the swing torque is increased by 9% on this model over the previous version. Speaking to the operator of the 670, he tells me that the Caterpillar 245 used to be able to shove a 48t block up the quarry ramp at full revs, while the new 670 can shove a 51t block up the same ramp at half revs, which is a testament to how far modern excavators have come with technology.
Cooling
Keeping everything cool under pressure is a large radiator and oil cooler that are laid out in a parallel arrangement, instead of the conventional in-line arrangement on most other machines. Hitachi claims that this parallel arrangement is much easier to clean with the air conditioner condenser able to be opened for easy access and cleaning of both the condenser and the radiator located behind it.
Cab
The cab has been redesigned on the 670 to help increase operator comfort and productivity. The controls now use short stroke levers for a more comfortable working environment helping to reduce fatigue.
Visibility is improved with sliding windows on the front and side, which enable communication between the operator and other workers such as a banksman.
Foot space has now increased and the travel pedals have been redesigned for easier operation. A flat floor allows for easy cleaning, while ergonomic controls and switches, fully automatic air conditioning and a radio complete the package.
Undercarriage
As you might expect, the undercarriage on the 670 is strengthened in many areas to cope with the demands that working daily in a quarry puts on a machine. The swing circle ball bearing has more balls, which increase the loading capacity by 7%, according to Hitachi. The tracks are subject to more strengthening, with widened upper and lower rollers to increase the contact area, while the idlers and sprockets are increased in diameter to improve durability. The track links are also enlarged to aid strength and durability with the master pins pressed in place to avoid disengagement.
Boom and arm
The 670 comes with a heavy-duty “H-Boom” and “H-Arm”. They achieve their added strength by using thicker plates and stronger steel than the standard configuration with a damage prevention plate and square bars added to the arm to help further improve durability.
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