By Bob McCrickard.
Editor's note: While Bob may no longer be with us, he is still sharing his love of roofing with others. Enjoy one of his previous posts
Bracklinn Falls Copper Covered Bridge is a cool little wood bridge spanning over a gorge about 20 meters (66 feet). It can be found near the town of Callander, Scotland and was recently rebuilt in 2010 after being washed away by a severe flood in 2004.
Surrounded by thick woodland meant that helicopters couldn't be used in the construction. And because of its remote location, materials had to be delivered and framed by craftsmen on-site using Douglas Fir from the Heritage Plantation in Dunkeld.
The beautiful truss design provides the stand-alone structural strength to span over the narrow but deep gorge. It was positioned across the gorge and set in place by using a temporary rails system that was called a “Herculean Effort” by Project Manager Kenny Auld.
Engineers from Strong Bridges, based in Crief, built temporary steel rails that went across the gorge. They then mounted the bridge on skids in order for it to be pulled across. Construction of the new bridge took 3,000 hours to complete.
The large timber rafters, instead of an arch construction design, give this bridge great strength when designed with a Pratt like truss system.
Copper was the choice of roofing to protect the structure and looks to be a basic sheet copper rolled over the huge timber rafters. I believe the use of copper not only has a long life cycle but also retards mold and fungus. When moisture comes into contact with copper, there is a reaction to the metal that precipitates a chemical that prevents mold and fungus from growing on the wood structure below the roof.
It is an interesting little bridge to look at that my fishing buddy Rodman told me about. Now tourists and locals will be protected from the elements while enjoying an iconic view of the falls.
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