DEMOLITION MADE EASY

The three new models, designated CB 500, 700 and 1100, have all been used in France for a number of years before exports were considered.

'It is so much easier to have the new machines on your doorstep,' said Eric Poncin from Ardennes HQ in Charleville-Mezieres. 'We are very jealous of our quality and go to great lengths to protect our products and customers, and if something does go wrong with a new model, we want to be there to put it right.'

Considering that the company was only formed in 1976, its growth rate has been rapid to say the least. There are now more than 3,000 different products - buckets, clamshells, grabs, forks concrete pulverisers and crackers - in the catalogue and over 300 dealers around the world, with 165 in the US. West Drayton-based PSE Machinery joined the Ardennes dealer fold in 1980 and quickly moved up to become the number one 'grab' outlet. Poncin says he hopes history will repeat itself with the CB range.

The figures following the CB prefix indicate the width of the jaw opening in millimetres and according to Poncin, if the material goes in the gap, the shear will crush it. The jaw opening and closing action, plus the built-in steel shear, is protected by worldwide patents.

Each jaw is mounted separately on its own pivot so that when fully retracted, they present a square opening, thus allowing material to be taken to the very back of the throat where the greatest force is generated. Unlike a conventional single pivot scissor system that tends to expel material, the Ardennes jaws pull the material in as they close.

The steel shear is a particularly neat solution comprising a fixed hollow leg extending the full length of the jaw down one side of the frame. When breaking concrete, the jaw retracts into the fixed leg so there is no restriction to the overall operation.

To use the steel shear, you start with the jaws closed, wedge the steel between the moveable jaw and fixed leg, then open the jaws. Bolt on, hardened and serrated inserts take care of wear and abrasion. The smallest unit, the CB 500 has a shear jaw opening of 220mm, the CB 700 has one of 370mm and the big CB 1100 - 460mm - which means the 700 can cut beams up 120mm and the 1100 up to 250mm in a single pass. Again the company insists, if you can get it into the jaws, there is enough force to cut it.

Poncin added: 'The secret is in the way the jaws operate. The transversely mounted hydraulic ram exerts all its force directly in the same plane as the breaking action where as scissor action jaws can only exert around 70% of the total ram force.'

The CB 700, mounted on a Fiat-Hitachi 200 was showing off its power on an old Heathrow runway and apron concrete with an original spec of 60N. To give you an idea of just how strong that is - current road spec concrete is around 40N, while the material in the Channel tunnel is rated at 100N.

Not only that, the quartz aggregate makes it extremely abrasive. Both crushing and haulage is an expensive business with crusher jaws, truck bodies and bucket teeth being rebuilt, or replaced on a 10 week cycle.

All three breakers have built-in 360¼ continuous hydraulic rotators and in the hands of a good operator, selecting 300-400mm thick slabs from the stockpile was not too difficult. Once the CB 700 had the material in its jaws - as the company claims - it broke it.

Details: enter 702 on card