27 June 2012

Scotland bridges tour

I've recently returned from a tour of bridges in Scotland, mostly in the eastern Highlands. The trip took three days and visited 35 bridges. Over the next few weeks, I plan to feature every one of them here.

Some of them are bridges I've mentioned previously, but hopefully a fresh look at them will do no harm. Some are bridges I've been to before, but never covered here. A significant number were new to me, and almost certainly some of them will be new to most of you.

The raw numbers are 8 arch bridges, 9 girder bridge, 5 cable-stayed bridges, and 14 suspension bridges. There's no prize for spotting that those numbers don't add up to 35.

I'll be featuring bridges both ancient and modern, although mostly somewhere in between. Some are well-known, but several are particularly obscure, generally undeservedly so. Several of the bridges are among those in Britain which any serious Pontist should try and visit once in their life.

There are a few themes to look out for along the way.

First is "water". Unluckily, I chose the wettest weekend possible for the tour, so there was a lot of water under the bridges, as well as over, and as a result many of the photographs are far from the best.

Another theme is "eccentricity". Dividing the bridges into four classic typologies, like I did above, really doesn't do justice to most of these bridges. Several are unique, survivors of an age of experimentation, examples of design by trial-and-error rather than facsimiles of the last design to successfully roll off the computer production line.

Third comes "serviceability", particularly in relation to wobble. Quite a few of the bridges, even the most recently built, exhibit dynamic behaviour which goes well beyond what modern codes permit. Does this really matter? How important is individual context? Perhaps in 35 bridges time there may be some answers.

The last theme that leaps to mind is "immateriality". Several of the bridges slim down their material to an extent that I think any modern designer would find it impossible to match. One in particular almost seems to defy material science. These are a challenge to the contemporary engineer, something to marvel at and to aspire to.

Hopefully along the next 35 or so posts there will be something of interest to most of my readers. There will be a few thrills: bridges which are spectacular, and certainly a few in spectacular settings. Also a few spills, or at least cases where the Happy Pontist was very nearly spilled.

Okay, that's the introduction out of the way. The next post will expand a bit further on the logistics of the bridge tour, and then it will be on to the bridges themselves.

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