04 December 2011

London Bridges: 17. Challenge of Materials Footbridge

I spotted these photos from earlier this year lurking in my files, and realised it was a bridge I hadn't yet featured here. These aren't great photos, I was in a hurry and didn't have time to find a good viewpoint.

The bridge was designed by Whitbybird and Wilkinson Eyre and spans the main hall in London's Science Museum, providing access to the Challenge of Materials gallery.

The bridge is intended to use the bare minimum of materials, with 16m spanned by 8.5 tonnes of glass and steel. The deck comprises 828 glass plates placed on edge, the ideal arrangement to resist the compressive stresses introduced by the cable-stay support arrangement. The balustrades are in the form of glass plates.

The "stays" are a closely spaced fan of stainless steel wires, each a mere 1.58mm thick. Each wire runs from a support fan bolted to the building's columns, down to the deck, across the underside, and then back to another support fan. Tie-down cables below the deck ensure rigidity and prevent vibrations.

From several angles, as will be apparent from the photographs, the ultra-slender wires almost become invisible, leaving only an evanescent presence in the air. From other perspectives, the light glints off the wires, and elements of their cat's cradle geometry are revealed. This is my favourite aspect of the design: the supporting wires define a wider space for the walkway to rest within, but the effect is subtle rather than intrusive.

The glass floor and sides, which you might expect to give a sense of precariousness, are surprisingly unexciting: the sheer rigidity of the structure eliminates any sense of peril.

Further information:


David said...

Thanks again for your interesting site! My first impression was that this highly-tuned structure was like a harp. Following your links one finds that it does indeed make music as well providing access. Maybe it's expensive per m2 of deck but what a great entry to the exhibition.

Salvatore Aguilar said...

Using glass as bridge materials is something you don’t see often. I was kind of surprised that you didn’t find it exciting; it looks really thin from afar! Well, I think it was made to give the guests an impression that the bridge isn’t sturdy. Great job both in design and construction!

Unknown said...

Wow! I’ve neither stepped foot on nor seen a glass bridge yet! I think it’s going to be a great challenge for me to step on this glass bridge especially if it’s already 10ft high. Good job to whoever was behind this glass bridge!

-Alphonse Daigle