NEWS that English Heritage is to honour Sankey Viaduct with a special heritage plaque is a fitting accolade for the borough’s only Grade I listed structure.

In 1826, the Act for the Liverpool & Manchester Railway (L&MR), the world’s first intercity railway, was passed by Parliament. George Stephenson was the company’s principal engineer for the 31-mile route between Liverpool and Manchester but it soon became clear the route needed to cross the Sankey Valley, west of Newton-le-Willows, about halfway along the line.

The Sankey Valley presented two obstacles: Sankey Brook and the Sankey Canal that was constructed to link the St Helens coalfield to the River Mersey.

As a result, Stephenson had to devise a route for the railway to pass without obstructing barges on the canals and maintaining gradients for steam trains using the route.

The Sankey Canal was built for Mersey ‘flats’, the common sailing craft used on the rivers Mersey, Irwell and Weaver as well as along the Lancashire and North Wales coasts.

Stephenson’s solution was to construct an embankment on the west side of the valley, roughly 823m long. Then, to cross the brook and the canal, a viaduct that met a smaller embankment on the eastern side was constructed, with 70ft headroom being left for the flats’ sails.

Stephenson designed the viaduct in conjunction with Thomas Longridge Gooch, his chief draughtsman.

One hundred thousand tonnes of marls - a mixture of fine-grained minerals - and moss, compacted with brushwood, were used to construct the embankment, handled and transported with the simplest of mechanical aides, as work on the viaduct began in 1828.

Some 200 piles were driven up to 30ft into the ground to provide solid foundations for 10 piers. And the nine arches - each with a span of 50ft and built of brick faced with stone - carried two tracks 70ft above the valley floor.

The last seven sailing flats passed through the Newton Common Lock to St Helens in 1919. The canal was formerly abandoned north of this point in 1931 and in 1963, the last navigable section closed and the waterway was subsequently filled in.

Today, almost 200 years since it was built, Nine Arches still stands proud as a testament to 19th century engineering.