Forth Rail Bridge
March 4, 1890: The Forth Rail Bridge opens. The cantilever bridge is located in Edinburgh, Scotland and crosses the Firth of Forth. It was opened by then Prince of Wales and later King, Edward VII. Until 1917, it was the longest single cantilever bridge span in the world but it was replaced in that category by the Quebec Bridge (longest span is 1,800 feet). Today, it remains the second longest cantilever bridge span and measures 1,710 feet in length. There are two of these spans. Today, the bridge is owned by Network Rail Infrastructure Limited.
Before the bridge was built, ferries were used to cross the river. In 1805, a pair of tunnels was proposed, one running in each direction, however it was rejected. In 1818, James Anderson presented a design for a three-span suspension bridge but his plan called for only 2,500 tons of iron and it would not have lasted long against the wind shear in the region. Sir Thomas Bouch was designing a suspension bridge in 1879 when his Tay Bridge failed and collapsed while a train was travelling across it, killing all aboard. His credibility was dashed, as well, and a new design and designer were considered. Sir John Fowler and Sir Benjamin Baker were called upon to submit designs and the bridge was built by Sir William Arrol & Co. with Allen Stewart as resident engineer.
Even today, it is considered to be an engineering marvel. The bridge measures 1.6 miles in total length and is 151 feet above the high tide watermark. There are double tracks for passage in both directions. There are two main spans each measuring 1,710 feet and two side spans which are each 680 feet. There are 15 approach spans of 168 feet each. Each of the main spans is made up of two 680 feet cantilever arms which support the central 350 foot truss span. The weight of the bridge superstructures is 50,513 long tons (51,324 tons) which includes the 6.5 million rivets holding it together. Also used were 640,000 cubic feet of granite.
The Forth Bridge was the first major construction in Britain to use steel. The Eiffel Tower was built around the same time and was made using wrought iron. Using the Bessemer process produced steel with unpredictable strength, making it unsuitable for structural engineering. In 1875, the Siemens-Martin open-hearth process was developed and the steel was of consistent quality making it feasible to use for large structural projects like this. The 64,000 tons of steel used in the bridge were provided by two mills, one in Scotland and one in Wales. It took seven years to build and at its peak, there were 4,600 men working on it. There were 63 deaths and hundreds of men were left crippled by serious accidents. Eight men were pulled from the river by boats positioned under the construction site. Today, 190 – 200 trains cross the bridge per day.
Don’t build a bridge if you want to use the pillars of doubt and suspicion. – Tasneem Hameed
The youth gets together his materials to build a bridge to the moon, or, perchance, a palace or temple on the earth, and, at length, the middle-aged man concludes to build a woodshed with them. – Henry David Thoreau
Your problem is to bridge the gap which exists between where you are now and the goal you intend to reach. – Earl Nightingale
The hardest thing in life to learn is which bridge to cross and which to burn. – David Russell
Also on this day: I’ll Drink to That – In 1634, the first tavern opened in the American colonies – in Boston.
Three Ships Go Sailing – In 1493, Columbus’s ship returns to Lisbon, Portugal.
Collingwood School Fire – In 1908, the Collinwood school fire occurred.
France – In 1790, France was divided into 83 departments.