To demonstrate the delicacy of his giant crane and his skill operating it, John Bates lowered the steel grab and plucked Adam Evans’s hard hat from the ground.

Then he lowered the helmet and gently dropped it on Adam’s head. This German-made machine can swing 30 tonnes of metal through the air. Between the railway track just outside Shipley and the Oddfellows Hall pub lies a wonderland of 16 acres that would delight any child.

There are nine large cranes lifting tons of metal either with a huge steel claw or a magnet the size of a dozen manhole covers.

You’ll see cars dropped into cutting and crushing machines and pop out minutes later in rectangular metal cubes.

On a good week, two mile-and-a-half long trains shift up to 5,000 tonnes of metal either to stainless steel smelters in Sheffield or steel, iron and cast-iron smelters in Cardiff.

Business worth an estimated £23m a year rattles round the yards of Bradford family firm Crossley Evans Ltd, providing jobs for 40 people.

John Evans, who bought the original firm, Crossley, in 1984, is still managing director. His sons Adam, purchasing and production director, and Matthew, transport director, have worked with him for the last 11 years and eight years respectively.

Matthew, a former project manager with BP, got a degree in business studies at Manchester University. His brother Adam has a BA in logistics and supply chain management from Newcastle University.

Mr Evans, who used to sell scrap metal machinery internationally, joined Crossley’s in 1969. His firm is one of about 30 scrap metal dealers in the Bradford area.

He said: “In the 1960s and 1970s the business had a Steptoe image. That has gone. Recycling is now the buzzword. I suppose the business has changed for the better, although it was simpler to run then.

“You literally had fixed prices for ten different grades of metal. These days prices can fluctuate £60 a month. The market is very volatile.”

In the old days, cars were simply crushed. These days, Matthew said, liquids, glass and plastic were first taken out and tyres removed. Similarly, car batteries were simply mixed up with other scrap. Not any more.

Around the walls of the office are posters warning of the dangers of radiation and sealed containers. There are also pictures painted by visiting school children.

Is the scrap metal recycling business competitive? John Evans smiled and said: “It’s very, very competitive. Two years ago, the volume of materials coming through here was vast. Since the recession, the business from engineering works has fallen off by 40 to 50 per cent.

“We used to do 100 tonnes of metal off-cuts a month from manufacturers. Six months ago that was down to 20 tonnes. That’s a hell of a drop. It’s picked up slightly.”

Ferrous metals – steel, iron, cast iron – sell for about £150 a tonne. The price for non-ferrous metals – copper, aluminium, titanium, platinum and silver – can vary between £3,000 to £8,000 a tonne, Adam said.

Itinerant rogue traders can make life difficult – and give the trade a bad name. But that’s what happens when economic circumstances are difficult, when demand outstrips supply.

Matthew said the amount of material from council recycling stations in West and North Yorkshire wasn’t as great as it used to be.

Adam said: “The majority of our customers are manufacturers in the North East, Yorkshire, the Midlands. Most of the material we collect in our own vehicles. We also buy from other scrapyards in the Bradford area.

“We process between half a million and a million tonnes of metal a year. On a turnover of about £23m, we make between £200,000 and £300,000 profit.”

Should the economy go on the scrap heap, there is plenty of room for expansion. Only about half of Crossley Evans’s 16 acres are used, Adam said.