Versatile Kobelco powerhouse for AE Yates

April 21, 2020

Headquartered near Bolton Wanderers’ Macron Stadium, AE Yates Group has been trading since 1870 and are one of the longest serving names within the UK’s civil engineering sector. Purchased in 1947 by current MD John Whitehead’s father Jack, the company developed as a civil engineering company working for local authorities, water companies and developers and is now a major regional player in the heavy civil engineering market. Whilst civil engineering still plays a major role in the company’s business, they are envied across the country for their expertise in delivering complex tunnelling and piling projects which now makes up the bulk of the company’s work. Further additions to the company portfolio have included soil stabilisation and now brings a “one stop shop” to developers for all underground construction techniques.

The range of equipment used by the company to perform their work is huge. Micro tunnelling machines, cranes and a huge variety of dedicated large piling rigs keep their Volvo heavy haulage outfit busy but for smaller piling works, the company has chosen to work with Bristol based Molson Group to carry a range of Movax and Grizzly piling hammers for their steel sheet piling arm of the business, SPI Piling Ltd.

The company has used the services of a number of New Holland machines for piling work, particularly the 235 compact tail swing machines as they provide a great combination of pump power and lift height combined in a small footprint. “We tend to keep our excavators on piling work for about 10 years.” Explains Glen Kilroy Group Plant Director of AE Yates “We don’t put the hours on them as such and after ten years, they’ve usually done the work of a 5 year old excavator.” With the New Holland name disappearing from the UK’s excavator market, when the time came to start looking at fleet replacements, Kobelco was the obvious choice as the New Holland excavators were in the main a repainted Kobelco. “They have definitely moved forward in terms of comfort for the operator.” Glen comments “While underneath, they are still the quality product they have always been.”

After looking at other manufacturers and feeling let down by their response and lack of willingness to work with the company, a call to Andy Wilkinson of Molson led to a deal being done for five new Kobelco machines, two SK210 in standard excavator specification, an SK230 short radius, SK300 and SK350. Both the SK230 and SK350 have been added to the fleet to carry their range of augers and piling hammers whilst the SK300 has been converted to carry a piling rig in place of the standard dipper.

EARTHMOVERS were invited by SPI Piling over to Oldham to see the SK350 in action where it was installing a run of piles around the edge of a new development.

The site of the former Breeze Hill School was being developed for Oasis Academy Leesbrook who were commencing the construction of a large two and four storey building to replace the former school demolished in 2013. Built on the site of a former landfill, a large cut and fill operation was being undertaken by Irlam based PP O’Connor who had employed the services of SPI Piling to install a piled façade to one elevation of the project.

The 37 tonne Kobelco was being used with a Grizzly MG90 side-grip piling hammer to install a 50m run of 7m piles to retain the existing ground and enable the building team to construct a new access road to the academy. The piles will eventually finish at 2m above the new road level. One of the most striking differences between the SPI machine and a standard earthmoving excavator is the fitment of a two-piece boom. More commonplace on the continent on excavators of this size, two-piece booms on 35t plus machines are few and far between in the UK. “We opted for the two-piece boom as it gives us a combination of advantages” Glen explains “We’re able to lift and drive a longer pile than with a standard boom and also keep the piling head closer to the machine therefore increasing the lift capacity and the stability of the Kobelco.” At almost 38 tonnes the Kobelco is a large machine. Sitting on top of a temporary haul road come piling mat, the Kobelco’s first task is to unload an artic’s worth of 7m long piles. Packed in bunches of six, each pack weighs about 3 tonnes, well within the lifting capabilities of the machine. Quickly dropping the piles of at various stages along the haul road, the Kobelco is quickly back into position to recommence driving duties. Whilst the reach across the ground is the same as a standard excavating machine with 3.3m dipper, the two-piece boom version gains over 1m of extra lift height over the standard machine. The same point on the variable arm version is also 3m closer to the centre of the machine resulting in far greater lifting duties. Sitting on wide 700mm tracks, the SK350 gives a lower than normal ground bearing pressure of just 62kPa. This means that in certain ground conditions, the construction of a suitable piling mat is not required, a large cost saving for the main contractor.

Power to the SK350 comes in the form of a tried and tested 6-cylinder, 7.6 litre Hino diesel which pushes out 286hp at just 1600rpm. Whilst Jeremy Clarkson keeps banging on about ‘power’ this is not the main requirement of the SPI machines. “We need a constant and sustainable source of hydraulic pressure and flow for the attachment to function correctly. Glen explains. For the Grizzly MG90 to perform to its peak ability it requires 227l/m at a pressure of 310bar, something the Kobelco can easily supply thanks to a pair of 294l/m pumps. “The engines and pumps on our older New Holland excavators have been amazing.” Glen explains “We’ve not had a great deal of work to do to any of the older machines and in fact, we still have one on the fleet thanks to the upturn in work we have been experiencing recently. If the new Kobelcos are just as good, I’ll be very happy.”

Externally, apart from the two-piece boom, there is very little difference to that of a standard machine. A Kobelco manufactured FOPS guard protects the cab whilst a spark arrestor has been fitted to the exhaust system to allow it to work in petrochemical plants. For the eagle-eyed, there are a number of sensors on the boom and dipper for the Prolec system which has been fitted to allow the machine to work in restricted areas such as on rail projects. Inside the cab there are also a few changes too. The most noticeable of which is a new right-hand joystick. As part of the piling attachment package, the joystick is now a multi-functional version allowing single-handed control over the Grizzly MG90 head. Along with the standard Kobelco touch screen, the right-hand side of the cab is home to the small Prolec scree, the side and rear-view camera screen and a large screen associated with the Grizzly head, primarily showing the X and Y axis for the setting out of the pile.

The Grizzly is not a lightweight tool in any way, shape or form. Weighing just over 3.2 tonnes, the tool is capable of producing 2800rpm frequency combined with a centrifugal force of 90 tonnes to effectively and quickly drive in piles. Capable of driving piles both through the side grip and vertically, the Grizzly offers the company great versatility in its operation. “On the Oldham project we have encountered some very stiff material a few metres below the surface.” Glen explains “We’ll use the Grizzly to drive the sheets as far as possible before back driving with a Dawson HPH1200 impact hammer to complete the job. Thanks to the Hill Tefra hitch, the attachments can be swapped in a matter of minutes making the rig particularly suitable for this type of project.

The second Kobelco of interest was between jobs and was resting at the AE Yates yard. The SK300 had been equipped with a Mighty Machines mast and French made PTC vibro head. Primarily utilised for vibro stone column improvement and capable of handling mandrels of up to 7m in length, the PTC head is assisted in the driving operation by a 12t winch which pulls the head and therefore the mandrel down under constant pressure. Built up at Molson’s Warrington depot with the assistance of Yates’ engineers, the SK300 is seen as an ideal solution for a variety of piling situations and fits neatly into the fleet between the dedicated ABI piling rigs the company uses and the smaller machines on the fleet.

With over 10 engineers on their books, AE Yates will take over the repair and maintenance of the Kobelco fleet once their initial warranty period has expired. “We see very little in the way of issues with the kit.” Glen said “Depending on where the machines are in the country, we may just call on Molson to look after and issue. The way they have dealt with just a couple of small issues in the first months of service has been very good indeed.”

Whilst civil engineering contracts are going quieter, the increase in house building has seen the smaller rigs in the fleet struggle to keep up with demand, the addition of the new Kobelco machines will go a long way to keep up with client’s demands.