Bringing them down

Think demolition equipment and the first thought is likely to be of high reach demolition machines. While not a volume product, the high reach demolition excavator is without doubt the flagship of any demolition contractor’s fleet. Estimates suggest that 500 to 600 machines with working heights from 16 m to 35 m are sold around the world each year, with bigger machines over 40 m numbering in the 10s rather than 100s annually.

Most full line manufacturers are currently supplying machines into the marketplace with their own booms up to 30 m, addressing the ‘volume’ end of the market. However, specialist boom manufacturers are pushing the envelope at the high end, with booms over 60 m being the target of their ambitions.

The first such machine is now working with a Dutch contractor, Beelen Sloopwerken. Based on a Caterpillar 85 tonne machine, the Cat 385C TUHD has a pin height of 64 m, making it the highest reaching demolition excavator in the world. There is a taller machine available in Japan, the Kobelco SK3500D that has a pin height of 65 m, but this is based on a crawler crane carrier and weighs around 350 tonnes.

Developed by crane specialist Rusch Krantechniek and Cat’s Dutch dealer Pon Equipment, the 385C TUHD actually weighs 150 tonnes, including the boom, and the carrier has been heavily modified, so that it has little resemblance to the original big Cat, apart from the cab.

Probably the leading demolition rig specialist in Europe is Kocurek. Based in the UK, it supplies high reach booms for just about every manufacturer’s machines, and also carries out the necessary modifications to the base carrier to create an integrated package. The booms it produces are normally in the 20 to 50 m range, but it is rumoured that 2007 will see at least two machines sporting Kocurek booms in excess of 60 m.

Key to every +30 m Kocurek design (and the Rusch one, too) is the use of telescopic elements in the boom. This allows the boom to be lifted from the horizontal to the vertical and then telescoped out, requiring less power and allowing a lighter weight base carrier - always the controlling factor on the length of boom that can be carried. A carrier weight of 150 tonnes or over is considered essential when going beyond 45 m.

These machines are usually supplied with a boom quick connect system to allow the machine to change over from high reach to standard earthmoving mode as quickly and simply as possible. Kocurek is not alone in saying the boom changes can take as little as 45 minutes. Obviously, this has considerable benefits for users, in that it provides a high degree of flexibility and means that the machine is not sitting idle when high reach is not required.

Height is not everything, though. Kocurek product manager Bradley Higgs said, “Ultra high reach is the headline side of the business, but there is another area that we are looking at, and that is carrying tools weighing up to 6,5 tonnes up to around 30 m.”

Contractors are increasingly encountering stronger materials with improved reinforcement as the buildings they are working on decrease in age, hence this requirement, and tools of this weight, and therefore power, are required to efficiently crush and process material.

The company is also looking at solutions for more confined workspaces. It is planning to launch a 16 m boom mounted to a Case CX225SR zero tail swing machine. Requiring minimum modification, the machine should still weigh in at 23 tonnes, but will not feature a boom quick connect system. Kocurek is hopeful of selling 10 units per year.

Making a point

Of course, demolition contractors make use of the full gamut of standard machines available to the construction industry. From skid steers and mini excavators, through wheeled loaders up to the largest excavators, they all have a place on today’s demolition sites.

Attachments make the machine. A wide range of specialist tools, from hydraulic hammers through concrete crushers/pulverisers to shears is available for use by the demolition flagships and their standard siblings in a demolition role. However, guidance notes from the UK’s National Federation of Demolition Contractors (NFDC) point out that hydraulic hammers should not be regularly used on high reach demolition rigs - their booms are designed to carry and use less dynamic tools, such as crushers, pulverisers and shears.

The most popular demolition tools, according to Cat Work Tools managing director Gary Zoromski, are multitools. As their name suggests, these offer contractors a single main tool that can be fitted with different jaw sets for different functions.

They are available for use on a wide range of carriers, with the smallest used on 1 tonne machines, right through to the giants that go on 125 tonne machines.

There is also a wide range of dedicated crushers, processors and shears, with a similar range of use. No matter the machine, you will find one that will fit and perform efficiently.

Size has traditionally meant power - the bigger the attachment, the more powerful - but that may be about to change in the not too distant future. Mr Zoromski said, “We have put a technology and product development programme in place to drive our R&D effort, making use of the considerable resources available to Cat. Included in this is research into materials.

“If we could produce a 2,5 tonne tool, using composites and other high strength materials, that has the same performance as one of today’s 6,5 tonne tools, there would be no need to modify the carrier. This would be a much better way to go.”

He went on say that Cat’s product line is likely to be very different in terms of models and capabilities by 2012 as a result of this effort.

Improved quality of materials that have to be processed is also driving tool developments. Mantovanibenne developed its MS120R multitool for Italian contractor Filli Baraldi, which uses it on a 125 tonne Liebherr 964, specifically to deal with modern large reinforced concrete foundations that could not be efficiently processed using existing tools. The MS120R is the widest opening tool in the world when in concrete crusher mode, with a massive jaw opening of 2,5 m.

Atlas Copco is a major player in the attachments sector and is also constantly developing new models that offer improved performance and power. It told sister publication D&Ri that new models will be on show at the forthcoming Bauma tradefair, and that it will also add a new demolition pulveriser, the DP 2800, at the end of this year, although specifications are currently not available. During the course of 2006, it added the 1680 kg CC1700 combi crusher with a jaw opening of 0,75 m for use on 15 to 25 tonne carriers.