Smiths have been quarrying in the Oxfordshire area since the turn of the 20th century. Founded by Arthur Smith, the group has grown from its roots in agricultural contracting and steam haulage to its current position as a producer of aggregates and construction materials.
The Aggregate Experts
The dynamic, independent, family-owned company operates throughout Oxfordshire and the surrounding counties and has built an enviable reputation as a quality operator, winning numerous domestic and international health, safety and environmental awards.
The group operates quarries throughout the region, producing a wide range of washed sands, gravels and crushed limestone for delivery on its fleet of company-owned tippers. Further products include other aggregates, such as natural Cotswold decorative aggregates, building stone and recycled aggregates.
One of the latest operations is situated on the outskirts of Witney,where Smiths have recently commenced high-quality limestone extraction works at Whitehill Quarry.
While Smiths use their own fleet of excavators, loading shovels and crushing and screening equipment to process the limestone, the actual extraction works have been subcontracted to their near neighbours D&M Plant Hire.
From Plant Hire to Earthworks, Civil Engineering and Contract Crushing
D&M Plant,headed by father-and-son team Michael and Sam Meagher, has been trading for over 40 years from their base at Stanton Harcourt. Whilst traditional plant hire has played a huge role in the company’s expansion over the decades, stepping into contract earthworks, civil engineering and contract crushing and screening has provided the company with a steady flow of work, avoiding the ups and downs of the hire market.
Recent years have seen D&M win a variety of contracts on a huge tier 1 project which passes just a few miles from their base. Contracts on tier 1 projects have allowed the company to expand their fleet with several wheeled loaders and crawler excavators, mainly purchased from Molson Equipment at Avonmouth. “We have a good working relationship with the team at Molson,” Sam Meagher commented. “They have a broad product range which fits in with our operations, and this allows us to purchase a range of machinery from a single source. This has the added benefit of knowing that if anything goes wrong, we can sort it with a single phone call.
“The latest addition to our front-line earthmoving fleet has also been sourced though Molson and is proving to be a winner on both the production and efficiency fronts.”
Working Together at Whitehill
The contract at Whitehill called for the D&M team to remove limestone from the extraction and haul it to the processing plant, where Smiths’ own teams would take over. As the quarry lies in an area where blasting is not allowed, D&M turned to Molson to supply them with a machine capable of ripping and loading the limestone in a quick and productive manner.
Already operating several Kobelco crawler excavators, D&M have recently added the Japanese manufacturer’s latest model in the 50 tonne class, 55 tonne SK520LC-11e. This crawler excavator was specified with a set of 600mm wide pads, which are ideal for a machine which will spend much of its working life in the Oxfordshire quarries. A ground clearance of over 500mm ensures the machine can traverse almost any ground at Whitehill without the risk of getting bogged down.
Kobelco offers the SK520 crawler excavator with a pair of boom options, the standard 7m boom and an ME version with a 6.5m boom. D&M opted for the ME version fitted with a 2.6m stick to make the most of the machine’s huge 334kN breakout force. This meant that the excavator was capable of ripping out the large slabs of limestone on its own. The addition of a heavy-duty ripper and rock bucket, manufactured by Keen in South Wales, helps to make this possible.
Once the site was stripped, the teams steadily exposed the layers of limestone ready for removal. As the excavation has deepened they have brought in a Komatsu D65 dozer to manage the haul roads and ramps, as once the clay sitting on top of the rock gets wet, it becomes slick and hard for the Volvo A25G trucks to navigate safely.
Updated and Improved Kobelco Crawler Excavator
The SK520 crawler excavator has recently replaced the previous SK500 model, which had proved itself to be a very popular model for both earthworks and demolition contractors alike. Offering a combination of productivity and low fuel consumption, the arrival of the new model has been welcomed by many with over half a dozen machines already in the field within the UK.
Whilst the previous model took its shape from the smaller, more rounded Kobelco crawler excavator models, the new SK520 crawler excavator has a more angular appearance more akin to that of its bigger brother, the SK850. Under the skin of the crawler excavator lies a 6-cylinder, 16-litre Isuzu engine which kicks out a healthy 467hp and meets current EU emissions legislation thanks to a combination of DPF and SCR technology. Like any Isuzu engine, the latest incarnation of the 6WG1 offers a combination of power and fuel economy with the maximum torque level of 2050Nm coming at just 1300rpm.
Convenient Access, Enhanced Comfort
Like the larger SK850, the new SK520 crawler excavator design has been centred around allowing easy and safe access for servicing and maintenance work to be carried out. Large, sturdy doors open up on both sides of the upper structure to reveal easy to access components, with the engine further accessed from the top of the upper structure through the huge, strut assisted canopy. A Molson designed and built boxing ring surrounds the top deck, whilst a non-slip walkway along the nearside allows access to the rear compartment containing the fuel and engine oil filters and the hydraulic pumps.
The Dash 11 model uses the same cab from the previous generation of machines, but with a big step up in operator comfort and usability. Additional sound suppression on the spacious cab brings the operator’s noise level down to just 72dB making the working day a little more comfortable. An air suspended and heated seat along with revised positioning of the air conditioning outlets ensure the operator is comfortable and the windows always stay mist free. The operator interface in the Dash 11 models offers car-like ease of use with a rotary dial allowing easy scrolling and selection of machine functions. The dials and switches are all back lit allowing the operator to find them at any time of day or night.
With both trucks loaded and sent on the short journey to the processing area, the Kobelco crawler excavator is able to quickly swap from bucket to ripper to remove the next narrow band of the limestone slab. Unlike many quarrying operations where it is necessary to load trucks as quickly as possible, with the size and shape of the slabs, it is a more careful and calculated procedure when it comes to loading. Thankfully the two ADTs have had their rear tailgates removed to allow safer tipping at the processing area.
Even with its operating weight of 55 tonnes, the combination of greasy stone and tremendous breakout forces occasionally makes the excavator skid slightly across the surface when prying out the material. With a pile of material in front of it, the Kobelco then swaps back to the Keen bucket to load each truck again. Unlike many quarries where the required material may lay in thick seams, the limestone at Whitehill is in narrow bands which are interspersed with clay which calls for selective removal to ensure the stone is as clean as possible. “The project may not be one which dictates us to remove huge volumes of material on a daily basis.” Sam comments. “But it is one, when undertaken with care and attention to detail allows for the clean product to be processed quicker and easier and at a lower cost.”
D&M and Molson – a Winning Team
The recent additions of the SK520 crawler excavator, and several smaller Kobelco models, has strengthened the relationship between D&M and Molson. “We have been dealing with the Molson team for many years now with a variety of product lines.” Sam commented. “They’re very good to deal with, from the initial enquiry through to the parts and servicing we get from them. The last thing we, or our clients, want is a machine standing idle because it can’t be repaired.
“Molson are very proactive when it comes to getting things sorted and getting machines back up and running. With the Kobelco and their Komexs monitoring system we are able to keep a close eye on each machine’s performance and servicing requirements.
“Whitehill is the second project for the SK520 crawler excavator and the feedback from the operator has been excellent. It’s performing as we expected and giving us a good return on fuel consumption so far, which is important for us and our clients as we endeavour to reduce our carbon footprint wherever we can. As for the reliability, we have had no issues with it which is excellent.”
