Episode One looks at how one of the great engineering achievements of the Industrial Revolution, Pontcysyllte Aqueduct, was built, tests the date of an ancient gate at Hay Castle and explores what may be a lost church spotted from the air in the Conwy Valley.
You can see the episode on BBC Wales History
Royal Commission investigator Louise Barker has been studying Pontcysyllte Aqueduct with her colleagues to support the bid for World Heritage Site status . She discusses the structure with Peter Wakelin and shows him the evidence which is helping her develop a computer animation to show how it was built.
Pontcysyllte Aqueduct is one of the world’s greatest engineering achievements. It was built between 1795 and 1805 to carry the Ellesmere Canal to link the coal mines of Denbighshire to the national canal system and the heartlands of the Industrial Revolution . The terrain presented many obstacles to the engineers, William Jessop and Thomas Telford, the greatest of which was the crossing of the Dee valley. With its nineteen spans and height of 38.4 metres, Pontcysyllte Aqueduct was the tallest aqueduct in the world for 200 years. The spectacular achievement was made possible by the pioneering use of cast iron and the aqueduct became famous as one of the symbols of the new industrial age. The height made it necessary to find ways of reducing weight of stonework in the piers: by tapering them and constructing the top sections hollow. Studies of the clues surviving in the structure have revealed how the huge construction project was achieved. The piers were raised in stages of between six and eight metres at a time, moving south to north across the valley. Each gangway was supported from the stonework of the piers by two timber beams and diagonal braces held in cast iron shoes. Five successive levels of gangways transported materials from the construction yard on the north bank, probably by railway – as shown in the Royal Commission’s computer animation.
See Pontcysyllte on Coflein
Search Coflein for all features associated with the ‘Llangollen Canal'
Watch the computer animation"Constructing the Aqueduct"
Find out about transport in Wales.
Find out about the nomination for World Heritage Site status
Buy the World Heritage Nomination Document and related conference papers.
Royal Commission investigator Richard Suggett goes to investigate the ancient gates at Hay Castle with colleagues from the Oxford Dendrochronology Laboratory to find out whether it might be one of the oldest surviving gates in Europe.
Surviving gates from the Middle Ages are extremely rare. The gates at Hay Castle can easily be overlooked as they are in a long-closed gateway at the rear. The castle was rebuilt as a house in the seventeenth century and is now part of the longest-established bookshop in the town of books. The right-hand half of the gates is similar to the gates at Chepstow Castle, which were recently tree-ring dated to the later twelfth century. Tree-ring dating involves drilling fine cores across the grain of the timber and comparing the pattern of growth rings with dated historical sequences of good and bad years. The Hay gates were drilled, and the left hand gate was successfully dated to between 1610 and 1640. Unfortunately, the right-hand gate, which is almost certainly much older, could not be dated accurately. It may well be fourteenth-century or earlier. It might be possible to date it in future as techniques advance.
See Hay Castle on Coflein
Search Coflein for other castles or other features in Hay.
Visit the gates at Chepstow Castle
Visit the Hay Castle bookshop
Toby Driver, the Royal Commission’s aerial archaeologist, visits the site of a mysterious parch-mark in a field in the Conwy valley that he spotted during the drought of 2006. He investigates the site with David Longley and David Hopewell from Gwynedd Archaeological Trust to decide if they really are the ghost of a long-lost medieval church.
The dry summer of 2006 produced a surprise in a field near Llwydfaen in the Conwy valley – what appeared to be the characteristic outline of a small medieval church in a place where no church is ever known to have existed. Toby Driver spotted it during one of his regular flights to monitor known archaeological sites and discover new ones. David Longley and David Hopewell of the Gwynedd Archaeological Trust met him on the site with their geophysics kit to see if a magnetometry survey would confirm that there were remains below the ground, even though the parch-mark had disappeared completely. Magnetometry uses minute variations in the earth’s magnetic field to identify where the ground has been disturbed or burned. The shape of the building vividly appeared in the resulting computer chart. Unusually for a church, the building is not aligned west to east, and no associated remains were identified, but the shape of the remains confirmed by geophysics is unmistakably that of early Norman churches.
Look up the site on Coflein