by Nick Drew | Tue 09 Aug 2016
Shoring up the beaches
The battle to prevent coastal erosion around the UK continues unabated as Mother Nature does her very best to wash away large swathes of the coastline. The work to turn back the tide can be extremely challenging and requires the services of some of the most experienced contractors available, using some of the most modern and perhaps more importantly, the most reliable kit on offer.
One contractor with a long history in such work is West Sussex based Mackley Construction whose roots can be traced as far back as 1927 when it was, coincidently, established in the coastal town of Shoreham By Sea by John Thomas Mackley. Back in June 2014 Mackley was acquired by the UK subsidiary of leading Dutch dredging and marine engineering specialists Van Oord and today it works under the collective banner of Team Van Oord, a joint venture partnership between Van Oord, Kier Group, Royal Haskoning DHV and Mackley Construction.
The company has recently been working on the first phase of a major project for Bournemouth Borough Council on the beach just to the east of Boscombe Pier. The £3.6million project is part of an ongoing 17-year programme of works which will cost around £50million and will see 53 groynes removed and replaced with new timbers. In addition dredging will take place out to sea to pump fresh new material onto the beach to replenish the famous yellow Bournemouth sand. Most of the funding for this work is coming from the Environment Agency in the form of a grant to the local council.
For this project Mackley Construction has invested in a brand new Hyundai HX520L hydraulic excavator which has been supplied by Hyundai dealership Molsons. As a company Mackley have not historically ran Hyundai machines since the late 1990’s when it had a Robex R 450-3 in its fleet, in more recent years that fleet has been dominated by machines from the Hitachi stable, Mackley’s Plant Manager Adrian Passos told us more about the decision, “The Hyundai machine was specifically purchased for this contract and similar jobs in the future. One of our main preferred suppliers ‘Ovenden Earthmoving’ run Hyundai excavators and was promoting them to us as a reliable and a good value for money alternative. Molson/Hyundai could also supply the excavator in the timescale we required, so it all worked well for us”.
The 50 tonne class machines seem to be popular for this application and on this job there were no less than three Hyundai’s including two R520LC-9A’s and the new HX520L, a Kobelco SK500 and a Komatsu PC490LC, all being supported by a Cat D6T LGP sporting the distinctive Van Oord livery, asked about the preference for the 50 tonne machines Adrian Passos said, “We prefer this size machine on these jobs as we need the power for excavation and lifting duties. As we work within the tidal zone we also need to have the capacity to do a large amount of work in a short amount of time before the tide turns”.
Adrian continued, “So far we have had very good service from Molson’s, they have performed well and responded to any queries I have had in a timely manner, overall it’s been a pretty good experience. It’s still early days with the machine of course, but so far both site and operator appear to be very happy with the machine”.
Talking about the operator, the man in charge of this new machine is Kevin Heater; Kevin has been operating machines for 25 years and was keen to give us his thoughts on the new machine. “I really like it to be honest, I’ve spent time on the hired in older Dash-9A’s here previously and I felt they were slightly faster in operation, but it’s still a quick machine for its size, like all Hyundai’s the cab is a fantastic place to spend your days, its comfortable and everything you need is close to hand, all round visibility is good too, you really couldn’t ask for much better! I simply cannot fault it for performance, but if I had to be picky it would have to be the access to the header tank is a bit tricky, as it’s a bit obscured under a panel, we are also having to get used to the AdBlue situation which we all know is an additional thing to worry about but they all seem to be going down that route now to comply with emissions regulations so what can we do eh”.
Kevin continued, “For this type of coastal defence work this size of machine is just right, plenty of power in the dig, fantastic lifting capacity and the speed to get the job done fast as we are often operating against the clock regarding the tides”.
The Korean built and Swedish powered machine has certainly impressed Site Manager Gary Alford who told us a bit about the project and what the machine would be engaged in, “The Hyundai is an ideal piece of kit for this type of job, its primary role on this contract has been working with the boarding gang, which involves bulk excavation, lifting operations and backfilling works. The machines wide footprint, sitting on 700mm track pads, makes the machine very stable, even when working on the sand which by nature does have a tendency to move about. This makes it the ideal choice for any heavy lifting work “over the side”. We have had the machine with us now for some 8 weeks and I must say I am pretty impressed with it”.
This technically challenging work involved the piling of 293 wooden piles using imported hard wood timbers from Africa and Suriname. These wooden piles were driven in using an excavator mounted Movax piling system. The piling itself was a tough job due to harder than expected ground conditions below the sand level. Excavation work is done from both sides to alleviate any load bearing issues. The machines dig out from the middle and cast out to the sides to form a platform/coffer dam capable of taking the width of the machine and keeping the sea water at bay while the work goes on. The timber boards are swung into place by the machine and are coach screwed in by the ground team. Any water that does seep into the excavation while the work continues is bailed out by another excavator.
When it’s time to backfill the process is reversed ensuring that material which is as dry as possible is put back in ensuring good ground stabilisation and bringing the level up evenly on both sides so as not to overload the structure on either side.
The machines work in two teams with one excavator on each side of the groyne and another machine performing dewatering while monitoring the condition of the temporary coffer dam at all times and of course keeping a keen eye on the incoming tide! As one would expect working in such an environmentally sensitive area all machines on site are using biodegradable oils.
With every new range of machines Hyundai continues to raise the bar in so many aspects but especially in the cab where quirky gadgets and creature comforts are in abundance for the discerning operator, making long days in the cab a pleasure and not so tiring at the end of a shift. In fact it’s hard to imagine how they could improve on the refinements in the Dash-9 series cabs as they were top drawer, but a quick glimpse inside proved that they have, starting with an increase to the interior space of up to 13%, depending on just how they measures such things.
Summarizing on the company’s latest acquisition Mackley Construction’s Plant Manager Adrian Passos said, “It’s early days with this Hyundai machine so far and the jury is out at the moment, we will see how we go on this initial purchase. But I will certainly consider further investment in the future”.