Located a short distance south of National Park in the central North Island, the Makatote Viaduct is one of several rail viaducts designed and constructed in the early 1900s as part of the Main Trunk Line development. It is also the one most easily accessible to the public.
Makatote Viaduct
Glasgow-born engineer Peter Seton Hay (1852-1907) designed many of the bridges along the North Island Main Trunk Line route, including the viaducts at Makatote, Makohine, Mangaweka and Taonui. He was also interested in the potential for the development of hydro-electric power generation in New Zealand, and produced an extensive report on this subject in 1903. Hay is, however, best remembered for his work on overcoming the problem of how best to develop a rail route over the Southern Alps in the South Island. Hay was educated in Dunedin, and became the first BA graduate of Otago University in 1877. He was subsequently awarded a Master of Arts degree in mathematics with first class honours.
All of the viaducts in the central North Island area were designed to the classic North American steel trestle pattern. They incorporate a series of open-work steel towers supporting Pratt trusses up to 30 metres each.
The highway passes under the viaduct on the south side of the valley.
The first of the central North Island viaducts to be completed was the Makohine Viaduct near Mangaweka, in 1902 (it was started in 1896). This large structure spans a gully some 76 metres deep. By comparison, however, the Mangaweka Viaduct (now demolished) stood an impressive 289 metres above the Mangaweka Stream. It was completed in 1903, only 12 months after work commenced.
The Makatote Viaduct, which spans a gully 79 metres deep and is 262 metres in length, was started in 1905 and completed in July 1908. It is now the highest of the viaducts on the North Island Main Trunk Line. This viaduct was built by a company called J & A Anderson Ltd, of Christchurch, who despite their best efforts had to endure considerable delays due to machinery failures, cement shortages, floods and foul weather before the structure could be completed. Because of the difficulty of transporting materials to the relatively remote site, the company established a modern workshop on site where they could manufacture most of the steel components themselves. This workshop was powered by a wood-burning boiler and steam engine, and was lit by electricity. A water turbine drove a stone crusher and concrete mixer, and an electrically-driven cableway assissted with access to the viaduct as it was constructed.
The IPENZ plaque.
The Makatote Viaduct was built to carry 84-tonne locomotives, but by the late 1920s all bridge and viaducts along the Main Trunk Line needed to be substantially strengthened to enable them to carry the new design locomotives, which were up to 140 tonnes with a maximum axleload of 14 tonnes.
A subsequent project was carried out during the 1980s to further modify the viaducts to enable them to carry the 18 tonne and higher tractive forces of the electric locomotives introduced as part of the electrification of the Main Trunk Line. Concrete electrification masts were also installed.
Makatote Viaduct showing the 2008 foundation unerpinning work.
The most recent project on the Makatote Viaduct was completed as recently as 2008. This involved the underpinning of one foundation with deeper foundations to protect the structure from scour of the stream bed.
The Makatote Viaduct has a Category I Historic Places Trust classification.
Geeky Getaways 