The Skew Bridge

	Believed to be the most skewed bridge in Britain, the angle is 23°

Not many people know about the Hereford to Gloucester Canal, a fairly insignificant waterway, but notable for the extraordinary bridge at Monkhide near Hereford.

The ancient Egyptians appear to be the first to build arches, but even in its later development by the Romans, the archway was always at right angles to the line of the arch. Canals and then railways might cross a road or river at any angle and the problem of how to ensure maximum strength was solved in a most ingenious way. Most visitors to Britain drive under or over such arches without taking a second glance, so be warned: if you drive under a brick arch beneath a railway line, stop and have a close look at the line of the bricks. You might be surprised.

In an ordinary arch the bricks are laid with the first course parallel to the ground. You can trace each line of bricks as it runs up and over and down to the ground again - the arch is, as it were, a succession of side-by-side arches one brick thick. The arch is, if you like, at right-angles to the line of whatever is on top of the arch.

In a skew bridge the arch is still at right-angles to the line of what is on top, but that means that the first course of bricks is at an angle to the ground. What is more, the lines of bricks form a helix that is most confusing to the eyes. Wikipedia will tell you more than you ever wanted to know about skew arches!

Richard Down, who teaches engineering and design in Hereford, tells us the story of this little-known waterway and its extraordinary Skew Bridge.

If you would like to know more about the Hereford to Gloucester canal, why not visit the Trust's website and learn about the work which is planned for the future?