Throughout the Roman Empire water was a key resource needed to feed their cities and especially in the hot arid places of the Mediterranean it was not easy to come by. The Roman solution was to transport water, often over vast distances, using conduits: aqueducts. These channels relied on gravity, a slight downward gradient, to shift the water. Built of stone, brick or concrete, the aqueduct was supported by the bridgework of columns and pillars.
It’s unsurprising then with the need for more roads, and later the railways, that the same type of bridge proved useful for crossing wide expanses, such as a valley, low lying rivers or other geographical features. Via is Latin for road, and ducere means ‘to lead’. The 19th Century word viaduct is derived from the same origins as the aqueduct.
Viaducts are enormously pleasing to the eye with their tall columns, equally distanced arches, level gradients (no need for slight inclines) and vast lengths. There are 171 viaducts in the UK, and many are for the railways which need level tracks.
The tallest viaduct in Britain is in Scotland Ballochmyle viaduct and is 52 metres high, and was built in 1850 to cross the River Ayr. It was commissioned by the Kilmarnock and Ayr Railway Company. At the time it was the biggest masonry arch ever built and it is still in use.
The longest masonry viaduct is Welland Viaduct (also known as Harringworth viaduct) which crosses the valley of the River Welland on the county borders of Rutland and Northamptonshire. It is 1.166 km (1.275 yards) long and has eighty-two arches. Completed in 1878 it carries trains on the East Midland network. While it was built a temporary village of forty-seven wooden huts sprung up housing nearly 600 people including women and children of the construction workers.
The viaduct required thirty million bricks and was completed in just thirteen months time. Bricklayers reported seeing the hand and foot prints of children on the bricks, probably created before they were fired in the kiln. During the First World War, the viaduct was attacked by German zeppelins intent on stopping the transport of troops. The line is mainly used by freight trains with passenger services only reintroduced in 2009.
The first viaduct for the railway was built in 1812, which was used for horse drawn plateways (rather like a tramline) and part of the Kilmarnock and Troon railway. Laigh Milton Viaduct has four arches and the railway sits just eight metres above the river.
Perhaps the most famous British viaduct, also in Scotland, is the Glenfinnan Viaduct. Built in 1897, its long sweeping curve is ideal for a films. And guess what it appears in many, and is best known for carrying the Hogwarts Express in the Harry Potter movies.
The viaduct is built of concrete by Robert McAlpine, who was nicknamed ‘Concrete Bob’. Legend has it that a horse fell into one of the piers during construction. Attempts to prove this failed until 2001 when scanning technology revealed the presence of a horse and cart within a large pylon. Unfortunately no amount of magic could have saved the horse.