Linklater's Scotland

Published on Sunday 7 May 2006 00:58

I STOOD atop the First Wonder of Scotland, and marvelled. Right up there, on the very summit of one of the three great double cantilevers of the Forth Bridge, I looked north to the sweep of the Lomond Hills and south to Arthur's Seat. Then I looked down.

It was a mistake. I am not, in general, afraid of heights, but when there is nothing but a thin piece of scaffolding between you and the swirling green waters of the Firth of Forth, 100m below you, a strange quirk of the imagination says, "Go on, jump. Just think of it, a couple of reverse flips and then a clean dive into the sea. What a way to go!" Your knees go weak. Your grip on the scaffolding tightens.

And then it begins to vibrate. Way down below, a miniature Hornby Dublo-sized train is approaching the centre of the bridge. It lets off a double hoot and, in a well-rehearsed safety drill, the men in orange jackets standing by the track acknowledge its arrival with a wave, then turn their backs on it and grip the hand-rail as it passes. The bridge shivers slightly, then relaxes.

These trains are lightweight compared to the thundering monsters the bridge was used to carrying in its heyday. There may be 180 or so of them every day, passing every 15 minutes, but they cannot compare to the massive locomotives, with their 50 wagons, weighing 900 tons, which rolled across the bridge on January 21, 1890, to test the stability of this revolutionary structure. They passed over safely, and so has every one of the billion and a half tons of trains and freight that have thundered across it ever since. "This bridge is as strong and solid and resilient as the day it was built," says Ian Heigh, the project manager for Network Rail, which owns and manages it today. "They used good steel, they were first-class engineers, they built it to last, and it has." He glances briefly over at its neighbour, the road bridge, a teenager in comparison, but already feeling its age. He says nothing.

There are things you see from this magnificent vantage-point that you would never guess at otherwise. The struts of the high girders, which plunge down from the top like the tracks of a rollercoaster, are not absolutely straight. Over the years they have sagged a little, so that the sight-line is endearingly bendy. So long as you don't look down, however, you feel supremely safe in the hoists that lift you smoothly to the top and along the walkways, protected by balustrades.

The bridge is surprisingly elegant, tapering from the top to a slim waist at track-level, more maiden than matron (Heigh always refers to it as "she"). And later, when we take a launch out to view it from sea height, its arches soar as gracefully as the Ponte Vecchio.

Heigh, who is 49 and from Bathgate, talks of the pride he feels in this, the biggest job he has had in his career as a civil engineer. "It's my bridge - at least, that's the way I feel. I'm responsible for it, and I aim to restore it to the very best state it has ever been in."

This is a big ambition. Ten years ago, when Railtrack, Network Rail's predecessor, inherited the bridge, it was in a sorry state. Large sections appeared to be rusting away, leaving its famous dark red blistered and peeling and looking as if it had contracted a virulent disease. That impression was reinforced when parts of the bridge were swathed in what looks, from a distance, like bandages. In fact, these are large plastic sheets, made of something called Enviro-wrap, which cocoons the lattice-work of steel and prevents the air around it being polluted as the old paint is blasted off and the new paint sprayed on.

Inside the encapsulation, as it is known, and protected by helmets supplied with clean air, up to 150 painters and blasters are at work on any one day. Once they were suspended on ropes in the open air. Now, safety is paramount. Workers wear special harnesses and stand on carefully constructed platforms, supported by a scaffolding system that is almost as complex and labyrinthine as the bridge itself. Whereas, 120 years ago, as many as 57 men are thought to have died in the construction of the original bridge, there has been not one fatality in the last three years of the present contract, and no one has had to take more than three days off because of injury - a remarkable safety record.

The old myth that painting the Forth Bridge is a never-ending process has not been true for some time. For years, parts of it were not touched at all. But what is happening now is perhaps the best and most effective treatment it has had in the 116 years of its existence. First, the peeling layers of old paint are removed by blasting, which takes it back to the raw steel, a process known as scabbing and scarring. Then - and it happens within hours, because exposed steel rusts quickly in the humid sea atmosphere - the first of four layers of paint is sprayed on. (Over the seven years of Network Rail's contract, an estimated 400,000 litres of paint will be used.) To get right into the nooks and crannies of its corners, and round the 6.5 million rivets that hold the bridge together, using an old-fashioned paintbrush is still the basic technique. I asked Heigh if he had ever had to tell his workers to go back and do some bits again. "Oh, yes," he says. "If it's not up to scratch, that's just what I do. But I have to say, they're pretty good at the job these days."

For a century the paint was supplied by the Edinburgh firm Craig & Rose, but these days it is made in Derby, and is a state-of-the-art glass-flake epoxy resin, which binds into the steel and gives it a hard, enamel-like surface. This should, explains Heigh, last for at least 25 years without having to be redone. "The paint excludes moisture and is about as impervious as you can get," he says. "It is a type that was used on the North Sea oil rigs, and has been developed since. I describe it as being like the platelets of an armadillo."

So, how bad a condition was the bridge in ten years ago? "The basic steel was fine, but if the corrosion had not been arrested then it might have been serious. It's not an issue now. The damage is only skin-deep - at worst a millimetre."

So when will it be finished, and how much is it costing? Network Rail subcontracts the work to several companies, of which the main one is Balfour Beattie. The firm has a seven-year contract, which runs out in three years' time. By then the bulk of the work will have been done.

Depending on the funding available, a decision will then be taken on whether to carry on and finish those areas that were painted a decade or so ago. Heigh's best estimate of a completion date is some time in 2012. The speed of work depends very much on the weather. There are still only 80 to 90 days a year when work is possible - you cannot paint in high winds and driving rain.

The job is costing 13 million a year at present, and by the time Network Rail has finished, more than 100 million will have been invested. It is money well spent. When, finally, the last of the scaffolding is removed and the 'bandages' unpeeled, a proud new bridge will be revealed - a tribute to the sound engineering and groundbreaking design that confirm it not only as the First Wonder of Scotland, but as a triumph of modern civilisation.