The oldest remaining structure in the Mangapurua/Kaiwhakauka farm settlements collapsed with no warning on a fine day last month, nearby landowner Dan Steele says.
The Depot Bridge was on the Kaiwhakauaka tramping track/Mountains to Sea cycleway. It was 4.5km from Whakahoro, spanning a gorge of the Kaiwhakauka Stream.
Above it was a suspension bridge built about 12 years ago, for current use and to ensure safety. When the old bridge went on December 12 it took the new one down with it. Mr Steele said no one was 100 per cent sure why that happened. "The old bridge collapsed on a fine day. Luckily there was no one on it. It's imploded in a way that the engineers clearly didn't think it would. It caught the new bridge and cables and it's broken the 40-tonne wire ropes and taken the whole new bridge down with it."
The collapse caused a flurry of Conservation Department activity before Christmas, and closed the Kaiwhakauka section of tramping track and cycleway. Mountains to Sea cyclists are now confined to the Mangapurua section instead.
An independent engineering investigation is taking place into why the new bridge failed. It could take months to get consent and build a replacement. The Conservation Department (DoC) is looking to put up something temporary in the meantime, senior partnerships ranger Les Judd said. The new bridge will be built and paid for by at least three parties - DoC, Ruapehu District Council - because it's on a legal road in the district - and Mr Steele because it's a vital link to 400ha of his farm.