At least 8,000 cubic metres of timber are hauled across restored iron bridges in Scotland's forested regions. The 322 bridges, built in the 1950s and 1960s from recycled city tram rails, are still in use in Scotland's most remote areas. The steel they are made of is as much as 150 years old.
Forestry and Land Scotland vehicles cross 322 so-called tram rail bridges that remain in active use in Scotland's forests. The bridges were built from tram line rails lifted 60-70 years ago in Glasgow, Liverpool and other large British cities.
Many of the bridges were built from recycled Glasgow tram rails, and Scottish timber is carried across them. More than six decades have passed since the city's last tram ran. This is confirmed by Forestry and Land Scotland, the organisation that maintains 322 bridges built from tram rails across Scotland's national forest estate.
These bridges were built using 6,000 dismantled rails. Each one was made by laying 17 or 19 rails across the abutments, depending on the span, with a concrete surface poured over the top to form a trafficable deck. The structures, simple in design, have proved far more durable than their builders could have foreseen.
Thousands of cubic metres of timber are carried across the bridges
Today these bridges allow at least 8,000 tonnes of timber to be moved each year through country that would otherwise be inaccessible to harvesting machinery. Forestry and Land Scotland design engineer Graham White notes that “how the rails reached the forestry sector remains a mystery”: “We don't really know how the Forestry Commission of the day came by these rails, but it was a marvellous way of recycling them,” he told the Scottish Herald. “Since the Forestry Commission was set up a little over 100 years ago, Scotland's foresters have had to live with hilly, hard-going terrain. Over the years a great many bridges have had to be built to give access to productive forests.”
“At present we maintain around 1,800 bridges of various sizes that provide access to forests and land for both work and recreation. From beneath the “rail” bridges you can see the old tram rails laid across stone abutments, with concrete poured over them. It is a method of construction that has not changed since the 1950s. The tram rails were laid in the cities at the end of the 19th century, so the steel now built into the bridges and “supporting” the work of Scotland's foresters is 100-150 years old. Scotland has the greater part of the tram rail bridges still in service across the whole of Great Britain – 322, compared with 68 in Wales and 58 in England. Inspection results and a review of upgrading methods are a standing topic at the annual Forestry Civil Engineering conferences.