The Lower Acheron Suspension Bridge in South Marlborough was built by engineering students from Canterbury University in 1945, with their brief being to build a bridge that would take ‘one man on a horse at a gallop’.
Having been closed to the public for years, the historic bridge is now just about ready to be used again, thanks to a team of dedicated DOC workers from the region who spent an ‘abusively hot’ two weeks dismantling and rebuilding the bridge, while retaining its original character.
All gear was taken in by road, with a helicopter used to carry over the timber and equipment needed. This involved a couple of early mornings for staff, who made up for a short sleep with an al fresco cooked breakfast beside the Acheron River.
Staff had attended a harness use and fall arrest training course before the project, and received further instruction on rope rescue at the site.
Planning and setting up fall arrest systems that would be effective at all times and still allow the staff to move around on the bridge was all part of the challenge, and only the occasional nut or bolt (and maybe a drill bit…) was lost over the edge of the bridge!
Screw jacks were used to take the weight of the main cables (which were still in good working order), while each tower was removed, rebuilt and reinstated. The steel connecting plates were able to be reused, but most nuts and bolts were new. Only one of the droppers, three transoms, about half the bearers and the decking was replaced – everything else was reused. The native beech wood was replaced with Blackbutt (Eucalyptus pilularis), a tough and strong hardwood timber.
The bridge is part of the ‘Molesworth Journey’, an attraction that incorporates short walks, lookout points, picnic areas and other historic structures into the drive between Blenheim and Hanmer, through Molesworth Station. It provides visitor access to the other side of the river for fishermen, walkers and swimmers, and will continue to be maintained as a historic asset.