Queensferry Crossing's 'ice bomb' saga may have some way to run
A classic case was the long-anticipated, new electric train fleet for ScotRail’s flagship route between Glasgow and Edinburgh, whose introduction was delayed for months after drivers found they couldn’t see signals clearly through the curved cab windows.
The Queensferry Crossing has suffered a similarly unexpected glitch. Who would have guessed the new bridge over the Forth would have had to close three times in a year because of “ice bombs” falling from its cables?
Nearly three years after The Scotsman revealed the first incident, in which three cars suffered smashed windscreens, tests in France are ongoing to find a solution.
Some progress was reported on Tuesday by BEAR Scotland, the firm that maintains the bridge for Transport Scotland, which confirmed last autumn’s trial cable cleaning had had a beneficial, if as-yet unquantifiable, effect.
Laboratory tests at the excitingly-named Jules Verne climatic wind tunnel in Nantes have also found adding coatings and de-icing compounds to a mock-up of the bridge towers also reduced ice build-up.
BEAR bridges manager Chris Tracey, a veteran of many years of looking after the parallel Forth Road Bridge, said the cleaning results “give cause for cautious optimism”.
As we've reported, he had told me in December: “If cleaning works, this might be the way forward – cleaning every year or couple of years.”
That would be good news for drivers because the trial cleaning between September and November was completed without the need for lane closures.
However, more snow was forecast last night and the problem could strike again.
BEAR said patrols would be monitoring for ice on the bridge while control room staff kept a close eye on information from ice sensors and cameras.
They will be looking out for the very specific combination of weather factors which cause snow to accumulate on the bridge, turn to ice and fall, all within around 15 minutes.
It’s a surprising phenomenon to afflict the crossing, having not troubled the 58-year-old Forth Road Bridge, and this story may still have some way to run.