"Chinese Bridges" by Knapp & Ong

I've recently been reading "Chinese Bridges: Living Architecture from China's Past" by Ronald Knapp and Chester Ong (272pp, Tuttle Publishing, 2008) [amazon.co.uk]. Well, I say, reading, but for the most part I have been marvelling at the pictures.

I'm not sure which Chinese bridges are best known worldwide, but I'd guess the most famous might include the Zhaozhou Bridge (pictured, below left, courtesy jrs65), Beijing's Jade Belt Bridge (pictured, below right, from the book), or the 2km Anping Bridge. All three are remarkable historic stone bridges, with the Zhaozhou Bridge particularly impressive for prefiguring similar Western achievements by many centuries.

More assiduous pontists will know that China is also in the midst of a truly massive bridge-building programme today: already, 8 of the 10 highest bridges in the world have been built in China, as well as 4 of the 10 longest spans.

However, the scale of the country is such that these represent only the tip of a very, very large iceberg. Luckily for us ignorant gwailo, Knapp and Ong's book helps expose a little more of China's vast and rich bridge heritage.

It's a lovely coffee-table tome, amply illustrated with Ong's excellent photographs of bridges both famous and unknown. I don't think there's a page without a good photo on it. It also draws extensively on historic Chinese prints and paintings, and is clearly a labour of love.

The book is in three parts. The first is a general history of "ancient" Chinese bridge building, a journey through different bridge forms ranging across "step-on block bridges" (stepping stones), megalithic stone beam bridges, traditional chain bridges and more. One thing that is peculiar is that despite a wealth of detail, little is said on the bridge designers and builders themselves - there's no figure like Perronet or Telford here. Partly this is because the book's focus is before the "engineering" age of bridge building, but it may also relate to a lack of available information, or to the inability of individual bridge builders to build a reputation across such a huge country. This section introduces a number of bridges covered in more detail later in the book.

The second part addresses Chinese bridges as "living architecture", and discusses the relationship of traditional folk culture, feng shui, and religion to Chinese bridge building and use. Many historic Chinese bridges were or remain the sites of Buddhist, Taoist, or other temples, and many more are decorated with traditional emblems intended to bring good fortune or ward off disaster. Attention to auspicious dates and rituals played an important part in the building of many bridges, to the extent that bridges sometimes lay half-complete for considerable periods awaiting the "correct" date to proceed to the next stage.

The main part of the book is a gazetteer of over thirty particularly remarkable structures, "China's fine heritage bridges". Knapp's text for each bridge often ranges far and wide beyond the structure itself. When discussing the garden bridges of Beijing, for example, the reader will learn as much about the history of the Palace gardens as about the structures that ornament them. For others, like the canal bridges of Zhejiang, the text discusses in detail local trades and crafts.

Not all the bridges are spectacular - several are essentially minor structures of little fame or historical significance. However, they amply demonstrate the charm of vernacular bridge building, and that's reason enough to feature them.

Easily the highlight of the bridges included is a thirty-page section on Chinese covered wooden bridges, particularly of the "woven timber arch-beam" type. These are perhaps less well-known (Troyano's supposedly comprehensive Bridge Engineering: A Global Perspective ignores them, for example), but for me they are the main attraction of the entire book. While there are many examples of covered bridges throughout the book, this section concentrates on a particular sub-species, exemplified by rough-hewn behemoths like the Yangmeizhou Bridge (pictured, left, from the book).

While some in this group consist of straight beam bridges, with some similarities to the well-known covered bridges of Switzerland and the USA, most are massive timber "arches", supported by logs interlocked together in a polygonal form. The structure is generally hidden behind timber slat cladding, giving them a coarse, inelegant appearance. I find them quite beautiful.

Knapp's own website has a series of PDFs illustrating a variety of Chinese covered bridges, but it's no substitute for holding this exceptional book in your hands.