BREAKING INTO A GOLD VAULT

David Wylie visits a large demolition site in Edinburgh to see the CJ Charlton Group at work on a large and arduous project

Having invested in additional demo-spec excavators, demolition and dismantling specialists the CJ Charlton Group, headquartered in Surrey, has recently expanded to cover the north of England and Scotland. We met their team undertaking an arduous, high-profile contract in Edinburgh.

The impressive concrete structure of Drummond House, on a business park near Edinburgh Airport, was no ordinary large office block. As the former headquarters of the

Royal Bank of Scotland, the structure contained a huge gold bullion and cash vault deep within its massively reinforced basement.

The CJ Charlton Group won the contract to demolish this building, part of an evolving southern extension of the Edinburgh Park business area. It will see the construction of a new network of modern office buildings with vehicle parking concealed below their landscaped decks.

It took the Charlton team almost four months to complete the soft strip of this impressive building, leaving just its heavilyreinforced concrete shell. The main structure features unusually high 5m ceilings on each of the three floors, together with a deep basement and the vault area. The floors are made up of 700mm-thick Waffle Slab reinforced concrete, supported by 700mm round columns, which are densely packed with 40mm rebar. The vault area is made from massive, thick, high-strength concrete, plus the extremely generous use of 50mm-thick rebar.

KOMATSU PC490HRD-11 BASIC SPEC

HIGH-REACH RIG

During our visit, Charlton’s Komatsu PC490HRD-11 high-reach demo rig, now with 2600 hours on the clock, was busy munching its way through the top floors of Drummond House. Working in the standard high-reach configuration, this excavator has a maximum pin height of 28m, providing a working height of up to 30m.

On this job, initially operating at a pin height of around 15m with a 2.5-tonne Demarec DCC25, twin-cylinder concrete crusher, the Komatsu’s extra reach allows it to work at a safe stand-off distance. It is equipped with a dust suppression system, with a water connection at the nearside rear of the machine and pipework running the length of the boom to the attachment. Using Komatsu’s quick-change system, a shorter mid-boom section will be fitted to tackle the lower levels of the structure, using the same Demarec attachment.

Director Chris Charlton said, “The Komatsu PC490 high-reach is a fantastic demolition machine, which appealed to us on a number of levels. First, it’s UK built and designed, we have a full factory warranty from start to finish and the back-up from the Komatsu dealer MKL is also extremely good. Before we bought it, we spoke to other demolition contractors and operators, who provided nothing but very positive feedback on its performance.”

With over 20 years of demolition experience, Charlton’s site manager Charlie Hutton said, “We’ve operated high-reach excavators from other leading brands in the past, but the Komatsu PC49011HRD is in a different class. The whole machine is very well engineered from the ground up, as it’s designed and built by Komatsu UK at their Birtley factory.”

At the controls was operator Darren Scott, who said, “The PC490 high-reach is a well-balanced machine, even with a large 2.5-tonne attachment fitted. The tilting cab offers a stress-free view when working at height, so it’s comfortable to sit in all day long and I can place the tool precisely where we need it to be. I’d go as far as to say it’s probably one of the best high-reach demolition machines I’ve ever operated.”

Other Fleet

Chris continued, “In addition to the Komatsu PC490HRD-11, we’ve also made investments in the latest low emissions excavators from Hitachi and Volvo, to offer our client high productivity and emissions on this project. From an excavator point of view, everyone is also particularly impressed with the latest Volvo EC380E.”

That view was echoed by Charlie, who said, “Our 40-tonne class Volvo EC380Es produce outstanding digging performance. When coupled with the high-performance Euro-fab buckets, I believe there’s nothing that’ll out-dig this machine. I’d go as far as to say you could put it up against a 50-tonne machine and it would outperform that too.”

In addition to this Volvo, a new Hitachi ZX490-7 and a smaller Volvo ECR145E were put to work on this project. As were several other machines from Charlton’s fleet, including a Hitachi ZX210 and a standard Komatsu PC490.

Bespoke Buckets

The new excavators deployed to this project were equipped with bespoke Euro-fab buckets. The package included a 3.3cu.m heavy-duty rehandling bucket, built using a Hardox 450 wear package and the Kprime P50RC tooth system. For the 50-tonne excavators, a 2.5cu.m extreme-duty rock bucket was ordered, complete with Hensley bolt-on side protection, heel and lip shrouds, and using 50mm Hardox 450 steel. The Volvo EC380E was equipped with a 1.8cu.m bucket, again with Hardox 450/Kprime P30 tooth combination.

Director Chris Charlton said, “With this prestigious contract in Edinburgh to deliver, and as Euro-fab is only 30 minutes from the jobsite, it meant we could visit the factory and see first-hand how dedicated the team was at providing the very best buckets in the market for this tough demolition application.”

Site manager Charlie commented, “It was a pleasure dealing with Derek Macaloney at Euro-fab, a genuine bloke who does what he says. The spec and quality of the four buckets he and his team delivered for this arduous application are outstanding. By digging out tough concrete rubble and rebar, we’ve worked the buckets and the Komatsu Kprime teeth package hard, and have no complaints on their performance and durability to date.”

Site Visit

Once the Komatsu high-reach demo rig had munched its way through a decent volume of material, leaving the arisings on the floor, a Hitachi ZX210 excavator with a hydraulically actuated magnet was used to pick out the rebar.

The new Hitachi XZ490-7, now with 670 hours on the clock, used the large 3.3-cube rehandling bucket to form a stockpile of material for crushing. This will be processed by Charlton’s Kleemann Mobicat MC110EVO mobile jaw crusher, which has a capacity of 450 tonnes per hour.

The stockpiled material was primarily loaded by the new Volvo EC380E excavator. Nearby, another EC380E, fitted with a heavy-duty muncher attachment, was used to break out any remaining rebar from oversize concrete pieces, before running it through the crusher. Handling the material from the crusher was a Doosan DL450 wheel loader, which carried the material a short distance to the large stockpile of sized product.

With 40- and 50-tonne excavators supporting the 60-plus-tonne high-reach demo rig, a factory-fresh, compact radius, 14-tonne Volvo ECR145E excavator was delivered to site during our visit. Equipped with a grading bucket, a digging bucket and a selector grab, it will be used to carry out a variety of clean-up and other tasks on site. It will get into places that the larger machines cannot reach, consuming far less fuel in the process.

Once the main building is cleared and the concrete foundations removed, a level 13-acre site will be left, ready for the client to redevelop the area.

Below: A Kleemann MC110EVO jaw crusher is fed by a Volvo EC380E excavator, while a Doosan DL450 wheel loader handles the processed material.