Mahinapua Creek Railway Bridge

South Of Hokitika, Over The Mahinapua Creek, Westland

  • Mahinapua Creek Railway Bridge.
    Copyright: Papakura Radio Club inc. Date: 8/01/2010.
  • Mahinapua Creek Railway Bridge. Image courtesy of www.flickr.com.
    Copyright: Shellie Evans - flyingkiwigirl. Taken By: Shellie Evans - flyingkiwigirl. Date: 13/04/2015.

List Entry Information

List Entry Status Listed List Entry Type Historic Place Category 1 Public Access Private/No Public Access
List Number 5010 Date Entered 28th June 1990

Locationopen/close

City/District Council

Westland District

Region

West Coast Region

Summaryopen/close

This historic place was registered under the Historic Places Act 1980. This report includes the text from the original Building Classification Committee report considered by the NZHPT Board at the time of registration.

The Mahinapua Creek bridge was built as part of the Hokitika to Ross railway line. The railway was constructed to open up the economic potential of this part of the West Coast for sawmilling, tourism and farming. Government authority to begin surveying and purchasing land for the railway was given in 1901.

Both the Mahinapua and Fisherman's Creek bridges were constructed by Hokitika contractor Thomas Dillon at a price of £1748. 11s.6d. Mahinapua bridge was completed in September 1905 and the railway opened from Hokitika to Ruatapu on 9 November 1906. The final section to Ross was not opened until 1 April 1909.

A new bridge across the Mahinapua was proposed in 1956 but never built, and the old bridge continued to serve until the line was closed on 11 November 1980.

Assessment criteriaopen/close

Historical Significance or Value

This historic place was registered under the Historic Places Act 1980. This report includes the text from the original Building Classification Committee report considered by the NZHPT Board at the time of registration.

The Hokitika-Ross railway line was built to serve the growing timber and tourist industries in South Westland and to encourage further settlement in the region. The Mahinapua Creek bridge stands as a physical reminder of that line and of the crucial role played by the railways in the development of the West Coast.

This historic place was registered under the Historic Places Act 1980. This report includes the text from the original Building Classification Committee report considered by the NZHPT Board at the time of registration.

ARCHITECTURAL QUALITY:

The Mahinapua bridge is one of only three wooden truss bridges remaining on the West Coast. Railway construction was the major preoccupation of the Public Works Department between 1870 and c.1920 and the bridge over the Mahinapua Creek appears to be an adaptation of the standardised design developed by William Hales' Engineering Branch to facilitate the rapid construction of rail bridges throughout the country.

It is the only one of the three remaining bridges to have been used solely as a rail bridge. It is also notable for its single truss and trestle approaches, the others having multiple trusses spanning the whole of their length. The bridge is of particular interest because of the skewed angle at which the truss was built to take into account the angle at which the bridge crossed Mahinapua Creek.

TOWNSCAPE/LANDMARK VALUE:

The rail bridge is a distinctive feature in the immediate Westland landscape. It will achieve a greater level of prominence if State Highway Six is rerouted to pass it close by after the new Hokitika River bridge has been built.

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Construction Professionalsopen/close

Hales, William (1830-1909)

William Hales (1830-1909) was born in New Brunswick and studied engineering in Liverpool before immigrating to Australia in 1853. After working there as a contractor for three years, Hales settled in New Zealand and subsequently joined the civil service as an engineer in 1861. In the forty-five years of government service which followed, William Hales held a variety of posts and was responsible for the design of lighthouses, bridges, wharves and roads throughout the country.

Having served ten years as the Auckland District Engineer, Hales was promoted to the position of Acting Engineer-in-Chief of New Zealand in January 1891. He was confirmed as Engineer-in-Chief in the following year and held this office until his retirement in 1906 at the age of seventy-six. During a long and productive career William Hales played a major role in the development of New Zealand's public works and he was a key figure within the Public Works Department at a time when it had become the biggest construction agency in the country.

Additional informationopen/close

Physical Description

This historic place was registered under the Historic Places Act 1980. This report includes the text from the original Building Classification Committee report considered by the NZHPT Board at the time of registration.

ARCHITECTURAL DESCRIPTION:

The bridge is over eighty metres in length and spans the Mahinapua Creek south of Hokitika. A single truss span, approximately twenty-four metres long, is supported by braced piles and approached by trestles carried on simple piles. The truss design is based on that of the Howe truss, first patented in 1840, which combines the compressive strength of timber with the tensile strength of wrought iron and steel in a structurally and economically efficient manner. Vertical steel rods provide tension members between the wooden diagonal struts. Further support is given to the truss structure by raked braces extending from the deck to the too chord. The truss is designed on a skew because the bridge crosses the creek diagonally rather than at right angles.

Three six-metre beam spans at the south end of the bridge and five at the northern end link the truss with the bridge abutments. The southernmost of these spans is a built beam to compensate for its greater length. The use of a truss span for this bridge was apparently intended to provide the necessary clearance for the paddle steamer which worked on the creek when the bridge was built.

Notable Features

An unusual feature of the bridge is that the truss and its piers are skew.

Construction Dates

Modification
1911 -
Raking piles added to improve the stability of the bridge.

Other
1985 -
Rails removed after operation on the line ceased.

Original Construction
1905 -

Construction Details

Wrought iron, steel and timber.

Completion Date

5th March 1990

Information Sources

Furkert, 1953

Frederick William Furkert, Early New Zealand Engineers, Wellington, 1953

Wises Post Office Directories

Wises Post Office Directories

1905

Noonan, 1975

Rosslyn J. Noonan, By Design: A Brief History of the Public Works Department Ministry of Works 1870-1970, Wellington, 1975

O'Connor, 1985

C O'Connor, How to Look at Bridges (for the Australian Heritage Commission), Barton ACT, 1985

Hopkins, 1970

H J Hopkins. A Span of Bridges - An Illustrated History, David & Charles, Newton Abbot (Devon) 1970

Conservation Plan

Conservation Plan

G.W. Carson & M.J. Morgan, 'Conservation Plan for the Mahinapua Creek Railway Bridge', Department of Civil Engineering, University of Canterbury, Christchurch, 1989

Other Information

A copy of this report is available from the NZHPT Southern Region office

Please note that entry on the New Zealand Heritage List/Rarangi Korero identifies only the heritage values of the property concerned, and should not be construed as advice on the state of the property, or as a comment of its soundness or safety, including in regard to earthquake risk, safety in the event of fire, or insanitary conditions.