Steel-eating microbes threaten to devour Britain's ports

By Kath Gourlay and Mark Rowe

By Kath Gourlay and Mark Rowe

05 December 1999

It could, in the wrong hands, become the germ-warfare choice for the 21st century. To the delight of power-crazed dictators everywhere, scientists have found a steel-eating microbe munching its way through the engineering structures of up to 90 per cent of British ports and harbours.

Port authorities in the UK are on high alert after a study found that nine out of ten British ports are affected by the microbes, which attack vital structural support systems in salt water environments, corroding sheet piling and leaving girders looking as though they have been riddled with bullet holes.

A whole mixture of bugs are involved, interacting with one another to produce hydrogen sulphate gas that leaves ports smelling of rotten eggs. The condition, known as Accelerated Low Water Corrosion, is caused when surface bacteria which use oxygen establish a colony and then interact with other bacteria that do not need oxygen, creating a "bacterial soup" in which the microbes can flourish.

The study, by an engineering wing of the British Standards Institute, found that as the bacteria grows, it gathers in the nooks and crannies of underwater structures and produces an acid which eats into the metal, turning it bright orange.

One of the specialist engineers tackling the problem said he was "horrified" by what he had seen. "The bacteria can go through sheet piling like a knife through butter," said Craig Donald, director of CorrOcean, in Aberdeen.

A manager of a second firm of Scottish corrosion engineers admitted his firm has found what he describes as "strange and virulent beasties" in water as deep as 180 metres. Felixstowe has been particularly badly hit. British Steel is so concerned at the potential for damage it has experimented with 30 paint formulations in an attempt to find one that resists attacks on sheet piling.

Professor Frank Walsh, of Portsmouth University's applied electrochemistry group, warned that the bacteria worked with devastating speed. "It can cut the lifetime of a structure from 100 years to possibly 40," he said.

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