The first, variously known as Liffey Bridge, the Metal Bridge, or the Halfpenny / Ha'penny Bridge, was built in 1816, Ireland's first iron bridge. It was imported from the Coalbrookdale foundry in Shropshire, England, and comprises a cast iron arch spanning 43m. When first built, a half-penny toll was charged to bridge users.
The bridge was extensively refurbished in 2001, but so far as I could tell on my visit, the bridge appears to have been very little altered.
I think this is a bridge which has aged well. The shallowness of the arch is bold and attractive, as is its shaping, with the slender crown and stout abutments. The pattern of the arch ribs seems more open and appealing than the criss-cross arch webs used on many other bridges of the time, and closely echoes Cantlop Bridge, built in England three years previously, and which was possibly designed by Thomas Telford.
I like the "two-layered" parapets, but the overhead ornamental lighting brackets are not to my taste.
Further information:
- Google maps / Bing maps
- Wikipedia
- Bridges of Dublin
- Structurae
- Halfpenny Bridge Refurbishment
- Ha'penny Bridge Restoration (video, 2001)
- The Ha'penny bridge in Dublin (De Courcy, The Structural Engineer, 1991)
- Civil Engineering Heritage: Ireland
(Cox and Gould, 1998)
- Ireland's Bridges
(Cox and Gould, 2003)
- Project History of Dublin's River Liffey Bridges (Phillips and Hamilton, Proc. ICE Bridge Engineering, 2003)
When I first saw this bridge on "magazine" photographs - already after the refurbishment -, I thought it was a rather new structure. I realized only later that the bridge is quite old. In my opinion, its modernity comes from the shape of the arch ribs: they appear as a curved Vierendeel-truss with varying height - a bold venture to analyze such a structure. First, I had the impression that the "idea" behind the shape was an abstraction - or better, a materialization - of a quadrilateral finte element mesh - to me, this is where the sense of modernness came from.
ReplyDeleteThat's an interesting perspective. For a modern variation on the theme, the Pont de Solferino is perhaps an appropriate example: http://www.francoisegomarin.fr/wp-content/uploads/2011/09/leopold_sedar_senghor.jpg
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