Casting replaces spinning process

Vivendi-owned Stanton Bonna Concrete, based in Stanton-by-Dale near Ilkeston in

Derbyshire, now has a turnover of £18-20M/yr. In the UK there are fewer

producers than France but larger companies – there are nine large companies producing

concrete pipes in the UK at just 15 sites, whereas in France and Germany there

are many more companies and hundreds of production sites.

Sales of concrete pipes in the UK are falling this year, with 2000 sales down

50% on 1999 and the first quarter of 2001 35% down compared with the first quarter

of 2000. According to Concrete Pipe Association (CPA) spokesman Keith Daniel:

“Our hope for privatisation was that investment would be better phased, but

in fact we’ve seen the sit-uation worsen. Water company engineers think there

is a ser-ious problem. In AMP3 Ofwat has effectively cut back spending on sewerage

by a third.”

To boost profitability Stanton Bonna has diversified into other areas including

the making of concrete railway sleepers. The company has invested in a new sleeper

production unit and is now hoping Railtrack will be forced to invest in Britain’s

railway network. According to Stanton Bonna’s managing director and CPA chairman

Barry Cooper: “Rail is not often used for concrete pipe transport in the

UK, because delivery times are restricted and unreliable. Most pipes are transported

by road.”

Despite concerns about cutbacks on sewerage expend-iture, Cooper is confident Stanton Bonna will continue

to grow and improve efficiency. The company has invested in casting machines which

can produce all of Stanton’s off-the-peg products from 300mm-1,800mm in diameter.

Concrete jacking pipes used to be made by a spinning process but this has been

superseded at most factories, including Stanton Bonna, by a computer controlled

vertical casting process.

Pipes are cast using vibration to compact a semi-dry concrete mix into the mould.

The pipes are made of Portland cement or a mixture of Portland cement and pulverised

fuel ash (PFA). The casting cycle now takes as little as 45 seconds with the input

composition closely controlled to ensure the pipe can maintain its shape immediately

once released from the machine. The Vi-king machines can produce 160 pipes in

an eight-hour shift.

Vi-King pipes will not join to any other cast or spun pipes as they feature a

‘Delta’ rather than circular gasket, which makes jointed sewers more stable. Pipes

can be cast with a number of features including uni-junctions, fixed-branch junctions,

pipe bends and lugs for safe lifting. A standard length pipe and rocker pipe allows

a section of main sewer to withstand manhole settling.

Manholes are produced in a variety of shapes and sizes from 900mm to 3,000mm in

diameter, with or without plastic-coated steel rungs for easy access. A perforated

chamber version is available which can act as a soakaway unit. Other drainage

products made by Stanton Bonna include Moduloval sewer sections and rectangular box culverts