Arapuni Suspension Bridge

Arapuni

  • Arapuni Suspension Bridge.
    Copyright: Mighty River Power. Taken By: Unknown.
  • Arapuni Suspension Bridge.
    Copyright: Heritage New Zealand. Taken By: K Pfeiffer. Date: 27/06/2010.
  • Arapuni Suspension Bridge. Image courtesy of Mighty River Power.
    Copyright: Mighty River Power. Taken By: Unknown.

List Entry Information

List Entry Status Listed List Entry Type Historic Place Category 2 Public Access Private/No Public Access
List Number 4168 Date Entered 21st April 1994

Locationopen/close

City/District Council

South Waikato District

Region

Waikato Region

Summaryopen/close

This report includes the text from the original Proposal for Classification report Jan 1992.

DESCRIPTION:

The bridge spans the Arapuni Gorge a mile downstream from the dam. As it was but a simple ancillary structure associated with what at the time was New Zealand's largest civil engineering undertaking, the suspension bridge itself received little mention in progress reports and media accounts of the project.

The structure, likely to have been shipped prefabricated from England, was erected by the British contractors for the Arapuni project, Armstrong and Whitworth. The concrete foundations were laid early in May 1925. By December of that year the steel tower was in place. However, as late as April 1926 the steel cables and decking had not been completed. The bridge, finished at some time during the following three months, seems not to have had a formal opening. It connected "top camp" (which eventually became the permanent Arapuni township) with the western-side of the gorge. Top camp accommodated the workmen employed on construction of the spillway, powerhouse, penstock and outdoor station. Two and a half years after the filling of the dam and headrace, rock near the penstock tunnels moved inwards towards the old gorge causing a slight sagging of the bridge on account of movement of one of the supporting towers.

Although the construction project was completed some sixty years ago the bridge continues to provide essential pedestrian access between the Arapuni village and the hydro-electric installation enabling efficient and convenient operation.

Assessment criteriaopen/close

Historical Significance or Value

This report includes the text from the original Proposal for Classification report Jan 1992.

The Arapuni Suspension Bridge derives its historical significance from its function as an ancillary structure serving the Arapuni power plant, a landmark in the history of hydro-electric development in New Zealand.

This report includes the text from the original Proposal for Classification report Jan 1992.

ARCHITECTURAL QUALITY:

The Arapuni Suspension Bridge has a certain rarity because of its substantial span and purpose as a permanent and frequently used pedestrian accessway. Few pedestrian swing bridges are as accessible to the general public.

TOWNSCAPE/LANDMARK VALUE:

Although hidden from the surrounding countryside because of its position in the river gorge the bridge is nevertheless visually impressive because of its considerable span and graceful profile.

Linksopen/close

Construction Professionalsopen/close

David Rowell & Co Ltd, Westminster

No biography is currently available for this construction professional

Additional informationopen/close

Physical Description

This report includes the text from the original Proposal for Classification report Jan 1992.

DESIGNER:

David Rowell & Co Ltd, Westminster

ENGINEER/DESIGNER:

The identity of the engineer responsible for the design of the bridge is not known. Clause 63 of the Arapuni contract document, prepared by the New Zealand Public Works Department, specified that the contractor provide a suspension bridge near the powerhouse site to the eastern side of the gorge. The clause stated that the bridge was to be of approved design and went on to set out a design brief. From steelwork plans prepared in 1924 and a name plate incorporated into the main tower, the designers appear to have been David Rowell & Co., Westminster. A site plan showing the layout and positions of anchors and foundation blocks was prepared by the New Zealand Public Works Department in 1925.

ARCHITECTURAL DESCRIPTION:

The bridge has a span of 152 metres between the towers and a grade of 1 in 10 descending from the eastern bank of the river. On the eastern bank a squat concrete "tower" supports the cable; on the opposite bank is a 21 metre high tower of open steelwork. The steel cables which pass over the towers are connected at each end to anchorages embedded in the hillside. The tar-coated timber deck is 1.2 metres wide. Suspender rods from the cables pass through the bridge deck and joists, and bolt onto steel angles. The bridge has a steel pipe handrail 1.2 metres above the deck. The sides between the deck and the handrail are enclosed by steel mesh. The bridge is approximately 50 metres above water level and is stabilised by four sets of wire guy ropes.

MODIFICATIONS:

Date Unknown - Rope handrails replaced with metal pipe.

Construction Dates

Original Construction
1925 - 1926

Construction Details

- One tower of bracked steelwork, and one tower of concrete

- Steel cables attached to concrete anchors.

- Steel hangers from cables to steel angles supporting deck

- Timber deck and joists bolted to steel angles.

Completion Date

1st January 1992

Information Sources

Appendices to the Journals of the House of Representatives (AJHR)

Appendices to the Journals of the House of Representatives

(D1) 1925, App. B p51, 1926, App. B p51, 1927 - Photos 'Powerhouse Site', 1930 - Public Works Statement pp XXX1, XXXIV

Archives New Zealand (Auck)

Archives New Zealand (Auckland)

BCCV A615 Box 38 2776 File 92/212/20/10, 'Arapuni Suspension Bridge Repairs 1972-5', David Rowell & Co Ltd., Drawing G5.254 File 71/126, 21 November 1924, 'Arapuni' Supension Bridge N.Z. - Details of Steelwork', Archives New Zealand (Auckland)

- Plan P.W.D. 62396 27.3.1925

'Layout Supension Bridge'

Auckland Weekly News

Auckland Weekly News

11 June 1925 p. 47; -31 December 1925 p37; 1 April 1925 p36; 24 April 1926

New Zealand Herald

New Zealand Herald, 12 July 1932, p. 6; 28 September 1933, p. 6.

24 June 1926 (p11(7) 'Progress at Arapuni...'

Putaruru Press

Putaruru Press

7 May 1925 p(2) 'Footbridge Across Gorge - The Foundation Laid'

Southwood, 1979

I J Southwood, The History of Arapuni, Wellington, 1979

1974 edition

Szigetvary, 1928

A. Szigetvary, Guide to Arapuni Dam and Hydro-Electric Works with Illustrations and Plan, Auckland, 1928

Engineer

The Engineer

6 February 1925. p161(3)

Other Information

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

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.