North Wales has a very rich heritage of engineering works extending back through history to Roman times and before that the mining of copper in the Bronze Age. That heritage includes the three very distinct and diverse World Heritage Sites. These include four Edwardian Castles, Pontcysyllte Aqueduct and Canal and the Slate Landscape of North West Wales. These sites extend across North Wales from Chirk to Harlech.
Four Edwardian castles
Historically the earliest is the Edwardian Castles of Beaumaris, Caernarfon, Conwy and Harlech. Created by Edward 1st’s engineer James of St. George beginning in 1277 at Rhuddlan. They were clearly a product of considerable detailed design and planning, that led in some instances to off site preparation and fabrication. The associated navigation works including canals and docks allowed stone and other materials to be brought in by sea and the castle to be provisioned by sea once in service.
The slate landscape of North West Wales
Slate represented a major industry in North Wales, dating back in history for centuries, but developing dramatically from the end of the 17th century through to the 19th century and 20th century. Quarries at Penrhyn near Bethesda and Ffestiniog continue in production now. Although gaining the slate was by traditional quarrying and mining, the infrastructure necessary to process, transport and export the slate products involved considerable amounts of engineering. The engineering artefacts that were created included power to drive machinery, inclined planes and railways to move the slate and ports and harbours for the export of the product.
The Slate Museum at Llanberis contains many interesting artefacts including the massive water wheel driving the machinery in the workshops. The restored inclined planes at the Slate Museum is an interesting artefact demonstrating how slate was moved around within the quarry. There are also remains of the trackways used with the quarries.
Pontcysyllte Aqueduct and canal
Transporting the slate to the ports and harbours was undertaken using narrow gauge railways, some of which survive as for example the Padarn Lake Railway and the Ffestiniog Railway. These railways survive now as preserved railways carrying tourists. Ports have also survived as at Penrhyn, Dinorwic and Victoria Quay. At Port Penrhyn the evolution of the port can be observed to be in several phases. Slates were exported widely to Boston in the United States and Baltic Ports such as Hamburg among many others.
The advent of canals and the extension of the Ellesmere Canal into North Wales from Ellesmere to Llangollen presented significant challenges which were to harness the skills of two of the greatest engineers of the 18th and early 19th centuries. Jessop and Telford worked together to create several ground breaking structures. Seen originally as a means of providing a more direct route to Ellesmere Port the scheme was never to be completed ending at Trefor Basin with a feeder from Llnagollen.
Driven in part by an earlier failure suffered by Jessop, firstly Chirk Aqueduct changed the way such structures were designed and built. A departure from an aqueduct carrying a clay lined canal. The formality of chirk with its masonry walls and cast-iron invert proved to be a far more efficient and effective solution to span the valley of the River Ceriog.
Passing through Chirk Tunnel with its innovative design of towpath and on to Pontcysyllte, the Dee valley presented an even more daunting obstacle. The decision was made to use cast iron to form the trough, dispensing with the masonry. This revolutionary concept led to the building of the iconic Pontcysllte Aqueduct, designed and built with the assistance of Hazledine. Water was to be provided from the River Dee upstream at Horseshoe Falls and the navigable feeder extends as far as Llangollen.
These three sites provide an insight into the period in which each was developed and also the development of the civil engineering industry.
