Historic viaduct to be by-passed

Waimarino Bulletin, Volume 3, Issue 14, 27 August 1985, Page 12

Historic viaduct to be by-passed

Work on the new $5 million Hapuawhenua Viaduct on the main trunk line north of Ohakune is we!l underway. The new bridge is just a part of the over $15 million of deviation work between Ohakune and Horopito being done in connection with the electrification of the railway. Project engineer on the site, Mr Gary Corbett who will be at the site until completion of the project, says the construction, which is due to be completed in May 1987, is the biggest project associated with the electrification in the country. With the last of the contracts for the project having just been awarded, nearly 1 00 people are to be working on the deviation shortly. Hayes and Eastwood from Wanganui begin earth works at the Horopito end in late August and H. Bullockhave been awarded the contract to build a new concrete bridge to replace the Taonui bridge. Both the Hapuawhenua and Taonui bridges are be-

ing replaced as it is more economically viable than to simply strengthen them. Mr Corbett says both bridges were built in 1908 and were the last two bridges to be built for the main trunk line. The replacement of the bridges allows for bigger

trains, heavier axle loads and faster speeds. As well as bridge replacements and culverts, the construction also includes grade and curve easement. About nine hectares of native forest have been cleared for the project, but Mr Corbett says as much care as possible is being taken with the native forest. Mr Lyall Irwin, senior ranger for Lands and Survey in Ohakune, was appointed to overview the works.

Mr Martin Nicholls, the landscape overseer for the project advises the Railways Corporation on matters relating to preservation and rehabilitation. Mr Corbett says that although they try to save as much native forest as possible where areas have been disturbed, Mr Nicholls advises on suitable replacement plants. Mr Nicholls was previously a landscape architect with Lands and Survey in Taupo. A problem with machinery coming into the National Park is the threat of bringing in Clematis vitalba or Old Man's Beard, a weed which is very difficult to control. Because of this, machinery which has come from high risk areas has to be steam-cleaned before entering the park. The idea for a deviation on the Ohakune-Horopito line has been talked about for 20 years, says Mr Corbett, but it has only now been able to be justified because of the electrification.