MJ’s big blue powerhouse

April 21, 2020

Wiltshire based MJ Church have recently expanded their fleet of Kobelco excavators with models from both ends of the range of the Japanese manufactured excavators. Supplied through Bristol based dealer Molson Group, the excavators represent the latest in Far Eastern technology to enter service with the company.

Operating from their base at Chippenham MJ Church offer a wide range of construction, civil engineering and waste management services across the South West and beyond and currently operate a huge range of machinery from three to fifty tonnes. Whilst excavators make up the bulk of the fleet, a wide range of dozers, wheeled loaders and dump trucks are offered alongside crushing and screening plant and a range of tippers, skip trucks and low loaders make the company almost totally self sufficient when it comes to delivering the often large and complex projects successfully handed over on an annual basis.

EARTHMOVERS caught up with the company on a large development project in Bicester, Oxfordshire where they were in the throes of undertaking roads and sewer installation works for a development of new executive houses.

With the contract to undertake the installation of infrastructure prior to house building, MJ Church were tasked with a variety of works from the initial site strip of the 6 acre site to the installation of dedicated haul roads and compounds. One of the first tasks after the initial site set-up was a series of 278 highway adaptations to form a new access to the site off the main A4095. At the time of our visit the bulk of the section 278 works had been completed with the company finalising the installation of kerbing, surface water drainage and tarmacking. Assisting with this work was one of MJ Church’s latest arrivals, a Kobelco SK75SR midi excavator complete with side-drain boom combination. The rubber tracked, 8 tonne machine was being used to excavate the final sections of drainage and whilst not using the full working range of its unique boom design to the maximum, the impressive little machine gave some indication of the possibilities available when using this machine.

The base machine remains standard and comprises of a compact tail-swing upper structure riding on a 2.83m long undercarriage complete with dozer blade. The standard king-post boom design has been replaced with a fixed foot version mounted centrally on the upper structure. Whilst the base of the boom remains standard, from a point where the arc of the boom straightens out is where the standard design ends. Between this point and the dipper connection lies a parallel arm arrangement which allows the operator to offset the bucket parallel to the upper structure. Similar in in scope to a standard kingpost design on a small excavator, the parallel design does away with the need for the operator to slew the upper structure left or right to allow for digging alongside a building for instance. Offering a maximum dig depth of 4.5m and a ground level reach of 6.5m with the upper structure in-line with the tracks, the parallel arm configuration allows for an offset of 1340mm to the offside and 1030mm to the near side. The recent addition into the Kobelco range is proving very popular especially when combined with the compact tail-swing carrier with a number of units being sold into major hire fleets for managed motorway schemes.

The second machine on site was far removed from the midi machine undertaking the section 278 works. Undertaking a similar job, but on a far larger scale, the firm’s newest arrival was hard at work excavating trenches for large diameter sewerage pipes to a depth of almost 7m. The early stages of the project require MJ Church to install several hundred metres of deep drainage for the housing scheme. All of the drainage installations are required to be installed within the confines of the road layout which means there are no tolerances as to the position of any pipe work.

Currently the largest machine available in the UK, the SK500-10 is the biggest Kobelco on the fleet and represents a new way of thinking for the company. “We wanted to be able to offer our clients something different.” Tom Church MD of the Plant & Transport division explains “This addition to the fleet not only gives us the capability to undertake larger scale earthmoving projects but also allows to approach schemes we’ve not traditionally undertaken such as residential, commercial and industrial with ease when big kit is required. ”

Specified with a standard 7m long boom and 3.45m long dipper stick the 51.3 tonne machine was coping well with the arduous task of excavating through some extremely hard stone to provide a suitable trench for the pipes to be laid in. Working from a position where a new large diameter access chamber was to be installed, the SK500 was excavating a drain run solely under its own power. Working up an adjacent road and through the same hard material an albeit smaller Hyundai R380 excavator was requiring the assistance of a second machine equipped with hydraulic hammer to chip away the stone before it was excavated. With a breakout force of 292kN the Kobelco was using a narrow BMC rock bucket the penetrate the material before quickly swapping the bucket over for a larger version to give the required width of trench. Thanks to the fitment of a Geith quick hitch, the changeover took no more than 30 seconds and allowed the machine to undertake steady progress through the trench.

Power to the huge machine comes from a 10.6 litre Hino diesel generating 271kW at just 1800rpm. The maximum torque from the Hino diesel of 1470nm comes at just 1400rpm meaning the Kobelco delivers a combination of high power output at low engine revs resulting in low fuel burn figures. Sitting atop a large undercarriage comprising of two top rollers and 9 bottom rollers sitting in a track frame of over 5.4m in length and with the option of being variably adjustable in width, the machine remains planted and stable under most conditions. The upper structure boasts typically Kobelco quality in its fittings and design. Large, well-constructed doors allow for access to the major components lying behind them with all of the components falling to hand once the doors are opened. Due to the physical size of the machine, ground level access to these components is very limited but thanks to the wide track gauge and adequate grab handles and ladders, access can be made from a raised position. Whilst many will rely on the information shown on the in-cab screen for the day to day checks of fluid levels, for those wanting to climb to the engine compartment the designers have provided a safe and reasonably easy access via the offside of the machine. Molson engineers have fitted a substantial boxing ring around the upper structure to provide a safe working zone for anyone requiring access to the top deck.

The cab on the SK500, likewise that on the SK75 Is finished to a high standard. Well laid out and appointed, the large cab offers plenty of room for the largest of operators without compromising on storage space within the work zone and behind the seat. Both of the Kobelco operators on site have been particularly pleased with the layout and comfort of their cabs with both agreeing that they don’t feel tired when they come to the end of their shift.

Both excavators benefit from Kobelco’s iNDr noise reduction system. The unique system encapsulates the engine and cooling pack into a single compartment from the air intake to the exhaust system effectively reducing the noise emissions from the unit.

The addition of the Kobelco excavators represents a new phase in the the company’s relationship with Molson Group. “We have been purchasing equipment from the team at Molson for a number of years.” Tom explains “They have consistently delivered the levels of service and back-up we and our clients demand. Falling behind on programmed time sensitive work is the last thing a contractor wants. With the Kobelco brand on the fleet we are quickly realising that they are giving us the high levels of availability, lower service and maintenance costs, something that any modern contractor requires.”

Written by Paul Argent for Earthmovers magazine.