British Iron Bridges

Wales

MENAI STRAITS BRIDGE 1826 Caernarvonshire Thomas Telford HEW 109 SH556 715 {N53 13’ 6.9” W4 9’ 40.6”}

As well as being one of the great engineering feats of history, the Menai suspension bridge is also one of the most spectacular and beautiful of bridges. It’s setting in the tidal straits between Anglesey Island and Gwyndd is a perilous site for a bridge as the straits there experience fierce gales as well as twice daily tides of twenty feet or more. Thomas Telford designed this bridge in 1817 as the crowning feature of his Holyhead to London road. Its total length is 1710 feet of which 559 feet are the suspended bridge. Seven bold stone arches reach from either shore out to the two pyramidal towers from which the suspended bridge hangs 100 feet above mean high tide from four sets of wrought iron chains.

John Wilson who was the contractor took seven years to build it. Severe storms over the years created the kind of damage to which suspension bridges are most vulnerable - racking and undulation - which the flexibility of the chains cannot resist. In spite of major repairs and modifications over the past 180 years, the bridge still stands essentially as Telford designed it. A number of books have been written about the challenges faced during its construction and those who love an engineering thriller would enjoy reading more about the making of this masterpiece and about its designer Thomas Telford: a very remarkable man.

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Category: Wales

LLEDAN BROOK AQUEDUCT 1836 at Welshpool on the Montgomery Canal PRN 30581 N52o 39’ 33.5” W3o 8’ 38.7”

This modest aqueduct is not so easy to find. It is located on a little side branch just off the main canal wharf in the heart of Welshpool. Park in the large public lot next to the tourist information center. Stand with the tourist center office behind you and walk to the far right corner of the parking lot to find the short footpath to the site. You will hear the noise of the water going over the little semi-circular weir as you approach the girder RR bridge which is used now for pedestrians.

The object of your search is still well hidden. Below the decorative iron guard rail, you must look carefully to see the bolted cast iron plates which are set into a masonry rim to form the aqueduct. The whole is supported by brick arches as the canal with its tow path is carried over Lledan Brook. George Buck designed the original in 1819 and this is the 1836 replacement based on his design by J.A.S. Sword who was the canal engineer beginning in 1833. It is thought that the weir was probably built at the same time.

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Category: Wales

LLANFOIST TRAM BRIDGE c. 1822 Glamorganshire SO285 130 N51o 48’ 39.6” W3o 2’ 19.5”

This seemingly very unremarkable looking bridge has survived over 200 years. It was built at the time of Hill’s Tram Road which about 1818-20 and ran parallel to and between the Usk River and the Brecon/Abervagenny Canal. This bridge carried an extension of the main tram line over the canal. It’s simple construction consists of cast iron deck plates laid on top of iron T section girders resting on masonry abutments. The tram cars were propelled simply by gravity (and hauled back up hill empty by ponies) and the only brakes were the ‘driver’ holding a stout stick to drag on the rail road sleepers. A similar bridge on the same tram line is at Pen y Pont further west on the Brecon Canal.

The landmark to look for as you come out of Llanfoist heading north is the old church on your left. Park on the right by the entrance to the nature preserve. Walk past the church up a steep and narrow road to the canal boat basin at the top where you will see a pedestrian tunnel ahead and steps to your right. At the top of the steps is your tram bridge.

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Category: Wales

LLANDINAM BRIDGE 1846 Montgomery Co. Wales HEW 850 SO025 886 {GPS N52o 29.050’ W 003o 26.223’}

This cast iron arch bridge spans 90 feet over the Severn River. It has three ribs which are stiffened by cross-members connecting them. The spandrels are filled with an open X pattern similar to Telford’s Mythe Bridge at Tewksbury. It was the first cast iron bridge in the county and was cast by Hawarden Ironworks and designed by the County Surveyor, Thomas Penson, who also designed the bridges at Abermule and Caer Howel.

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Category: Wales

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