Monday, 5 September 2011
The 8,300ft cantilever Forth Bridge, the construction of which was started in the 1880s, introduced a famous idiom '... be like painting the Forth Bridge.'
The construction of an earlier bridge got as far as the laying of the foundation stone, but it was stopped because it was designed by Sir Thomas Bouch, who had designed the Tay Bridge which collapsed in 1879, causing the death of the 75 passengers on board. Bouch's reputation as an engineer was rightly ruined and the then owners Northern British Railway cancelled his contract and two Englishmen, Sir John Fowler and Sir Benjamin Baker, took over the project.
Bouch's design had proposed a suspension bridge whereas Sir John and Sir Benjamin had proposed a cantilever structure.
Until 1917 when the Quebec Bridge was completed, it was the longest cantilever bridge in the world.
When I was a child I journeyed over the Forth Bridge on many occasions - most of them very happy times when I'd been on family days out and I can remember wondering how the Forth Bridge painters managed to do their maintenance in high winds, freezing temperatures and on wet, wet days, but they did.
Now Network Rail, who manage the bridge have announced it will not need to be painted again for 25 years and that brings to an end the task in which teams of workers used to have to begin repainting as soon as they finished the last coat.
Over the years various paints have been trialled in an attempt to find one which could provide some longevity and at last one has been found. It is a specialist glass flake epoxy similar to that used in the offshore oil industry.
Stripping of the old layers of paint applied over the past 120 years has taken 10 years and cost £130 million. Now it has been restored to its original condition and Network Rail say the new paint will preserve the steelworks for decades to come.
The bridge should be free of scaffolding by Christmas and it will be wonderful to view it from the road bridge without it. However, my favourite sight of the bridge is when my plane circles over the Forth and shows the full glory of such a feat of engineering. Then I know I'm home.
This news leaves me with a problem though. With what can I replace the idiom which I use reasonably regularly?