@Walter Hinteler,
Now that I like. Appears to work, looks good, nice and clever. I may have to nose around re who designed it.
Or, Walter, do you know if a design like this is common?
edit - here, from wiki -
The Rolling Bridge was conceived by British designer Thomas Heatherwick, designed by SKM Anthony Hunt with Packman Lucas, and built by Littlehampton Welding Ltd. The Hydraulic design and development was done by Primary Fluid Power Ltd in the North West.
The bridge consists of eight triangular sections hinged at the walkway level and connected above by two-part links that can be collapsed towards the deck by hydraulic cylinders, which are concealed in vertical posts in the bridge parapets. When extended, it resembles a conventional steel and timber footbridge, and is 12 metres long. To allow the passage of boats, the hydraulic pistons are activated and the bridge curls up until its two ends join, to form an octagonal shape measuring one half of the waterway's width at that point.
The maintenance and opening of the bridge is managed by Merchant Square Estates and it is up every Friday at noon. Following on from the maintenance issues in 2008, the bridge has been repaired and was fully operational from April 2009.
In 2005, the bridge won the British Structural Steel Design Award.[1]