BONHILL BRIDGE
https://w3w.co/reissued.reworked.flush
Today this bridge is a busy link between Alexandria and Bonhill with Jamestown just a little further on. Its pair of simple yet elegant steel arches support the road with vertical rigid hangers. This is the third bridge on this spot. While other bridges served the textile industry at various points along the river, the first for both pedestrians and vehicles here was built in 1836.
Consider for a moment how the River Leven was for so long both a means of access as a great divide between communities. The towpath, now a well used cycle and walking route was, as its name suggests, how shallow draft boats were drawn up by large horses. Ferries would brave the strong current to get people and their belongings across. There was a ferry here before the first bridge was built and others that served mainly the textile industry workers as discussed elsewhere. index.asp?pageid=718466 & index.asp?pageid=718468
The Leven Project website tells us that : A chain suspension bridge, at the instigation of Admiral Smollett, with a span of 40m, width of 4.5m and a load capacity of three tons supported on stone piers was erected to replace the chain link ferry and ford which had previously existed. For more on this see the link for that website below.
That first bridge was built in 1836. It was often referred to as the 'Bawbee Bridge' as the Scottish term for a half penny - the price of the toll - was "Bawbee".
That bridge was replaced in 1898, three years after the tolls were removed, by a steel arch truss bridge. This was similar, but somewhat smaller than the current bridge. It carried both road traffic and tramways over the river. The bridge span had been widened to remove the need for the earlier arched abutments and these were replaced with solid stone abutments taking the loads from the arch.
The bridge was substantially refurbished in 1962, but this could not ensure its future, and a few years later traffic lights and a 14 tonne weight limit were installed. [Sabre].
The current bridge is a tied arch bridge which Wiki describes : A tied-arch bridge is an arch bridge in which the outward horizontal forces of the arch(es) caused by tension at the arch ends to a foundation are countered by equal tension of its own gravity plus any element of the total deck structure such great arch(es) support. The arch(es) have strengthened chord(s) that run to a strong part of the deck structure or to independent tie-rods below the arch ends. for obvious reasons this type of design is also called a bow-string bridge. You may occasionally hear someone call this one simply the bow bridge.
The current bridge was opened to traffic in 1987, having been built alongside its predecessor which was where the old lamp standards and pyramids using the original stone now stand.
A great view of Ben Lomond.
The tied arch is very evident in the design.
Remnants of the earlier bridge's stone and cast iron lamp standards have been retained as small park area that is a popular meeting place, mainly for anglers.
SABRE : https://www.sabre-roads.org.uk/wiki/index.php?title=Bonhill_Bridge
THE VALE OF LEVEN project website : http://www.valeofleven.org.uk/levenbridges.html
WIKIPEDIA : https://en.wikipedia.org/wiki/Tied-arch_bridge
