Causey Arch & Tanfield Railway

At some time during the year 1725, building started on a stone bridge crossing the gorge of the Causey Burn close to the village of Stanley. It was built by architect and engineer Ralph Wood and funded by a group of coalowners known as the "Grand Allies". The Grand Allies included Colonel Liddell and the Honorable Charles Montague as well as Sir John Clavering, George Bowes and Thomas Brumell. These gentlemen acquired certain waggonways and collieries in the area and they were intent upon working together to exploit both the winning and the passage of coal. This they did by ultimately controlling both the price of coal and the cost of distribution of the mineral. Causey Arch, or Dawson's Bridge as it was then usually known, because it was built on the property belonging to Thomas Dawson, owed its origins entirely to the fact that a number of collieries existed on Tanfield Moor. The Allies wished to move the coals from these collieries as cheaply as possible to Dunston on the Tyne, so they had a wooden bridge built over the Houghwelburn around 1724. Over this bridge ran the Tanfield Branch Line. The Causey Arch is the oldest surviving railway bridge in the world and certainly the oldest stone railway bridge. Its builder Ralph Wood was haunted by the possible collapse of his wooden bridge which was used as a centering for the stone bridge. As a result, fearing that the arch would collapse into the burn he is said to have committed suicide by jumping from the top of it as soon as it was finished. There is no actual record of his death and as the failure was of the timber centering, upon which the stonework was formed or shaped, there seems to be no real grounds for his fears. Of course his arch was something new, and the span of the arch may have been done with unsubstantiated calculations. The arch of a slightly flattened type was built of freestone with a span of 105 feet, being just over 22 feet wide and 80 feet in height from the crown of the arch to the ground. Broad buttresses, project three and a half feet from the face and flank the arch on each side while running down to road level. According to John Brand the total cost of the venture was £1200 whereas Sykes suggests a more realistic figure of £12,000. The bridge carried a wooden waggonway consisting of a 4 foot wide gauge double track. It was a timber road made of oak and beech wood. Wooden rails were secured to the base with wooden pegs and the whole structure was strengthened and made more rigid when ashes and gravel formed the initial surface of the ground. The Causey Arch.

Labour costs were about 5 shillings per yard or £440 per mile. It cost about 1.5d (old pence) per chaldron of coal to keep it in good repair. Approximately 15,000 chaldrons used the waggonway annually at a cost of £95 per mile. The original wooden waggons (chaldrons) were pulled by horse and about 930 waggons crossed the bridge in each direction every day. It has been worked out that every 20 seconds a waggon would go by with an average 50 yards (46 metres) between them. The waggonway of the Grand Allies from Tanfield Moor to the Teams Staithes on the Tyne was about 7 miles in length although with all the branch lines joining it from additional collieries it was much longer. Wood's Arch must have been in use in 1725 in spite of the date of 1727 on the sundial on the side of the arch. Apparently a Dr. Stukely visiting Colonel Liddell’s collieries records its existence. Fire and a lack of coal closed a number of the collieries on Fatfield Moor during the 1730's. The last pit, Fatfield Colliery closed in 1739 and the line over the arch was closed shortly after having fallen into disrepair. Landslips damaged the approaches to the bridge on a number of occasions prior to its closure and alternative routes had to be found. By the 1770's the bridge was little used although parts of the original waggonway/railway continued in use until 1962. A section is now run by a private company assisted by enthusiastic volunteers – the Tanfield Railway. The arch has now been restored by Durham County Council during the 1970's and 80's. A Chaldron Waggon

An NCB 0-6-0 46 Tank Engine on the Tanfield Railway.