A stretch of road near me in Brewood had been 'patched' many times over recent years. Apart from the remarkable number of private cars the village seems home to, this road carries our bus service, the delivery vehicles servicing our local shops and a terrifying variety of agricultural machines, often with large trailers. As a result, 'patching' gave only brief improvement before the surface started breaking up again.
At the beginning of November, a circular was put out by the Council saying that the road in question was being closed for 8 days for essential work. So I was not surprised when I got up on 8th November to hear the muffled roar of a large diesel engine. I was quite impressed by the sight of the large yellow machine parked outside which was producing the sound. I recognised it as a 'Road Plane' and had a vague idea of its function in removing an old road surface but realised I knew little more and had not seen one operating. I had a closer look and spoke briefly to the machine operator as he filled the machine's water tank from a Fire Hydrant. The sheer size of the machine, carried on four tracked 'bogies', was notable as was the proliferation of colour computer screens provided to control the vehicle.
The machine was labelled as a Wirtgen product but it was being operated by Power Plane Limited. The machine was labelled as a 'W250' and the Power Plane website has brief details here, with links allowing download of two Wirtgen Documents in PDF format - the Technical Specification for the machine and a description of its use.
Before long, the machine in Brewood was demonstrating its ability to remove the old road surface by Cold Milling. I found the speed and accuracy of the process impressive.
In 1961 Reinhard Wirtgen, then aged 20, set up a haulage firm with one lorry. He developed the business into a construction firm, developing hydraulic shears for demolishing concrete structures and producing his own machines for road repairs. In 1970 he introduced 'Hot Milling' as a method for removing worn road surfaces and later 'Hot Recycling' as a method of repairing roads. 'Cold Milling' was introduced in 1979 and the business gave up contracting to concentrate on building machines at Windhagen, Germany. The Wirtgen Group now supplies machines worldwide and, in addition to Cold Milling machines, produces machines for Soil Stabilisation, Cold Recycling, Hot Recycling, Slipform Paving and Surface Mining. I'm afraid my ignorance of these techniques is almost total but the Wirtgen Site is a useful primer.
The W250 made short work of removing the old road surface, allowing other machines to lay the replacement surface. It was the massive yet sophisticated W250 which captured my imagination, but I should perhaps mention the Bomag BF600P Asphalt Finisher. Links on the Bomag webpage allow download of a leaflet and datasheet for this machine.
Bomag is a German company started in 1957 but it is now part of the much larger French group Fayat.
Photographs
Cold Milling Machine for Roads.
