When one of Amberley Publishing’s editorial team asked if I’d write a brief history of Britain’s aqueducts and viaducts, the chance to explore some of the nation’s bridges at close quarters felt too good to miss. Since the book was to be short, I decided to focus on the period from the 1760s to the 1960s which encompassed the development of Britain’s canal system; the growth of the railways and then, the spread of the road and motorway network. Not surprisingly, it was a time of prolific bridge-building.
Over the years, our understanding of the terms ‘aqueduct’ and ‘viaduct’ has undergone some subtle change The Romans used the Latin word aquaeductus in the context of water supply; in eighteenth century Britain, at the height of the canal era, the English term ‘aqueduct’ came to signify a navigable bridge that carried a waterway over a stream, river or valley. As for the word ‘viaduct,’ although it purports to yoke together the Latin words via – road - and ducere – to lead – it did not exist at all until landscape gardener Humphry Repton (1752-1818) coined it as a term for the ornamental walkways which he planned to traverse declivities in his genteel clients’ grounds. Repton thought the word ‘bridge’ rather dull; it suggested nothing more than the means of crossing a gap. A ‘Via-Duct’ as he customarily spelled it promised greater glamour. He could not have foreseen that the generation of surveyors who learned their skills on his landscape projects would in time move into employment with the emerging railway companies and carry the language of the one sphere into the other. That, at least, is my conjectural explanation of how the multi-span structures which carry roads or railways over valleys, rivers and estuaries have acquired the name of ‘viaducts’ but I am open to correction.
Please come, if you can, to Joseph Rogers’ and my book-signing session at the Suspension Bridge Visitor Centre on 23 March 2019, 11.00am – 2pm. We’ll be very happy to discuss our research, our adventures and our favourite bridges.
Pre-order your copy now from Amberley at £13.49 - a modest discount on the cover price of £14.99.
Research for the book divided itself between deskwork and fieldwork. The desk-work was necessarily solitary – a matter of distilling the gist of the history and technical detail into my narrative. For much of the fieldwork, I had my husband David with me - a welcome co-driver, inspired navigator, and steadfastly reassuring companion. We hit various set-backs. Much of our survey of the viaducts of the Settle-Carlisle Railway took place amid driving sleet; to access a fine if near-derelict aqueduct on the old Leominster Canal meant fighting our way through a bristling crop of Shropshire brambles, and my initial exhilaration at locating John Miller’s Ballochmyle Viaduct with its resplendent 181 foot-span (55.17m) central arch gave way to frustration on realising that to photograph of it through the trees in full summer leaf would be just about impossible. But the good days out-numbered the bad and to conclude this account, I’d like to flag up an aqueduct and a couple of viaducts which illustrate the way in which bridge engineering developed over time.
Near Wootten Wawen in Warwickshire stands the Edstone Aqueduct. Having opened to traffic in 1816, it carries the Stratford-upon-Avon Canal over a wide valley, crossing a tributary of the Avon, a minor road and a couple of railway lines on its way. The work of Birmingham-based engineer William Whitemore, it consists of a cast-iron trough supported on fourteen brick built piers. If, from that description, it sounds rather plain and functional, it is worth reflecting that Whitemore designed it on economical lines to suit the Canal Company’s tight budget.
Nevertheless, it is the longest aqueduct in England. ‘It’s not like Pontcyssyllte, you know,’ explained a friendly couple when David and I asked them for directions, and they sounded rather apologetic. But there is nothing disappointing about Edstone, and the walk along the towpath beside the great flanged panels of the trough – they reach approximately to waist height – is impressive by any reckoning.
The Edstone Aqueduct, seen on a fine evening.
Edstone Aqueduct, looking along the trough.
Sadly, the lattice girder viaduct by which the Taff Vale Extension of the Newport, Abergavenny and Hereford Railway crossed the Ebbw and Kendon valleys near Crumlin in South Wales no longer exists, but at the time of its construction in the 1850s, it was hailed as a triumph of innovation. The Railway Company and their engineer Charles Liddell reckoned that the sheer cost of building a masonry viaduct capable of withstanding the prevailing winds would be prohibitive. Instead, they decided that their crossing should be made of iron. Designed by Scotsman Thomas Kennard, its masonry footings gave a foundation to eight piers, each made up of fourteen slender cast iron columns bound and braced with wrought iron ties. Together, the columns supported the truss girders upon which the deck would rest. Completed, the Crumlin Viaduct stood some 200 foot (60.96m) above Ebbw valley floor, making it the highest viaduct in the UK and third highest in the world. Its surviving abutments, louring across the valleys, give some idea of its towering scale.
Crumlin Viaduct, c.1906 (Author’s Collection).
Before it opened to traffic, the Board of Trade arranged to load test it with six locomotives packed with pig iron. Not surprisingly, finding any willing to drive the lead engine for this exercise proved rather difficult, but eventually one John Thomas Jenkins of Pontypool volunteered for the task and the Board of Trade inspector instructed him to proceed slowly across the bridge, so that his team could note every deflection of the ironwork. In fact, despite these orders, Mr Jenkins built up steam pressure, accelerated and made an extremely rapid crossing. When Kennard, with the appalled inspector, confronted him afterwards, he explained that when eternity stares you in the face, you might as well meet it at full speed.
The Crumlin Viaduct closed in June 1964 when the line across it fell victim to the Beeching axe. Supposedly scheduled for preservation, the authorities made no provision for its maintenance with the result that it soon deteriorated beyond repair. Sad to say, it was demolished in 1967, but not before it made a glorious sunset appearance in the film Arabesque with Gregory Peck and Sophia Loren.
Crumlin Viaduct - The Western Abutment.
A very much smaller viaduct of twentieth century origin takes a minor road over the River Spey in the small Morayshire village of Advie. It was not one that I had planned to visit, but it was a most rewarding find. Completed in 1922, it consists of three reinforced concrete trusses on robustly paired concrete piers, and a plaque on the fabric credits its building to the Yorkshire Hennebique Company. Their adoption of the name of Francois Hennebique – the French engineer who pioneered the development and use of reinforced concrete – signals their prime interest and in their publicity material they described themselves as ‘Specialists in ferro-concrete constructions.’ Advie Viaduct, with its graceful arcading, complete with airy octagonal openings, makes a captivating example of the firm’s skill.
Advie Viaduct, looking along the deck.
The bridge’s promoter - J.F.Cumming, OBE, Lt. Col. Grant Peterkin, Mrs McCorquodale of Dalchroy and Alexander Hogg, County Surveyor and Engineer – deserve every congratulation for their vision and enterprise in authorising its construction. No doubt the inhabitants of Morayshire have often found it useful; to visitors like me, there is much enjoyment to be had from the chance discovery of a beautiful bridge in a remote location. It exemplifies all the enjoyment of bridge-hunting.
Advie Viaduct – the inscribed plaque on the bridge fabric.