How one Irish aggregates operation cut costs and nearly doubled its production by adding mobility to its crushing plant.

by Jim Breen

Thanks to ongoing advances in the aggregates industry, the focus in Europe is increasingly switching from stationary to mobile crushing and screening machines. This trend is strongly evident in Ireland, where mobile plant plays a key role in the aggregates sector.

Roadstone, a subsidiary of CRH, is just one of the many Irish companies that has recognized the benefits that accrue from “added mobility.”

The origins of Roadstone go back to the early 1930s. Initially called Roche Brothers, and later The Castle Sand Co., the business developed steadily during the 1940s. In 1949, Tom Roche launched Roadstone Limited on the Irish Stock Exchange.

Today, Roadstone employs about 1,500 people at more than 50 locations around Ireland. It manufactures and supplies aggregate, asphalt, and ready-mixed concrete. Its growing range of concrete and masonry products includes paving, roof tiles, and clay bricks.

Roadstone’s Two-Mile-Ditch Quarry, located close to Galway City on the west coast of Ireland, churns out a very diverse mix of products, including aggregates, gravel, asphalt, lime, concrete blocks, and associated masonry products.

Until 2001, the quarry had relied mainly on a stationary plant for its primary crushing operation. But then the company invested in a new mobile crusher (Kleemann MR 172), associated primary screen (Kleemann MS 18), secondary plant (Kleemann MF 14), and aggregates screen (Kleemann MS 20 P4).

This was just one of a batch of mobile crushers that Roadstone had purchased around that time. A year earlier, an MR 152 had been delivered to the company’s processing facility in Roscommon. Another MR 172, just like the unit in Galway, had been acquired for the company’s Mayo quarry. Moreover, plans were afoot to install further Kleemann mobile crushers in other locations such as southeast Ireland.

Plant selection

Maurice McLucas, location manager of Two-Mile-Ditch Quarry, says he chose Kleemann crushers for his operation because of his familiarity with the company’s products after working with a subcontractor that had been using them. “The [Kleemann] machines proved reliable and performed consistently when it came to size reduction,” McLucas points out.

McLucas also cites numerous reasons as to why his aggregates operation was interested in switching from a stationary to a mobile crusher. Prior to the changeover, McLucas says, 50-ton dump trucks were typically needed to haul the extracted material back to the stationary plant. This alone was a major cost factor. “By switching to a mobile crusher that can work at the rock face, we’ve reduced the amount of internal haulage that we have to undertake,” he says. “After each blast, we no longer have to load, haul, and reload all of the extracted rock. Now, we just load it directly into the crusher, which can be positioned exactly where we want it.”

Although much of the crushed material still has to be trucked back to the operation’s onsite processing plants (such as block-making facilities), the tonnage typically amounts to 35 to 45 percent of the total extracted material. But one or two dump trucks are sufficient now, whereas previously, at least three were needed, McLucas says.

An added bonus is that road-going trucks can travel right up to the rock face, where they can be loaded with “filling,” he notes. “Much of this is sold without any further processing, so it’s getting to the end-user with little or no re-handling,” McLucas says. “This all helps to cut costs.”