Working Safely at Height on an Auckland Icon

The iconic Grafton Bridge was originally constructed in 1908 and took two and a half years to complete. At that time, it was claimed to be the biggest span, reinforced concrete arch bridge in the world. How times have moved on.
The heritage bridge is now closed for seismic strengthening, as an investigation found that it would not withstand a major earthquake and that large vehicles were too heavy to use the bridge.

Access to reinforce the structure, a project scheduled to take until early 2010, posed significant working- at-height challenges around the provision of unfettered access to the underside of the bridge deck (some 30m from the ground!) and ensuring both worker safety and the safety of the drivers on one of Auckland’s busiest motorways below.

Specialist scaffold and engineered access providers, Camelspace were called in to provide a solution.

Phil McConchie of Camelspace said: “It was important that workers could access all areas of the underside of the bridge for its 100m length, and that the work necessary with heavy tooling and high pressure cleaning didn’t result in debris or tooling finding their way onto the road below.”

Camelspace built a suspended and total decked-out platform 6m wide and 100m long with 4m wide cantilevered split level ‘wings’ out each side to facilitate access to the outside of the bridge balustrades.

In all, over 100 tonne of scaffold was ‘hung’ from the bridge in a truly unique solution.

Scaffold construction was started at the top of one bridge pier and progressed in sections for approximately 100m until meeting the pier on the other side. Using a sequential cantilevered bay erection method devised by Camelspace especially for the job, scaffolders were always protected from the exposed edge of the scaffold by guardrails; almost entirely removing the need for fall arrest provision.

Mick Spratling of Camelspace said: 'We tried to approach the height safety issues on this project with a view to removing the risks instead of trying to prepare for, or mitigate their effects. I think we can be satisfied we’ve been successful in achieving this by virtue of the fact our scaffold was built and significant bridge remedial restoration work continues all without incident.'

For further information contact:
Camelspace,
visit: www.camelspace.com