Mount Henry Bridge

Statement of Significance

• The place has aesthetic value as a complex structure of a clean and simplicity of design using minimal materials that has been well integrated into the landscape.
• The place has historic value for its association with the spread of the metropolitan area in the second half of the 20th century and the government support of extensive road systems and latterly rail systems.
• The place has social value as it is a bridge that is well patronised by many members of the community for its function of enabling greater movement through the metropolitan area.

Physical Description

The Mount Henry Bridge carries the Kwinana Freeway across the Canning River below the heights of Mount Henry. The bridge was sensitively built, allowing for the retention of a wide strip of foreshore with its good spread of Nuytsia floribunda (Western Australian Christmas Tree) and the large and very old paperbarks in that area. The design of the Mount Henry Bridge allowed for a separate bicycle and pedestrian bridge to be cantilevered immediately below the traffic bridge.

The original bridge is of post-tensioned concrete. It has nine spans with a total length of 660 metres and a deck width of 28.8 metres. In cross-section, it is a double box-section, with the upper deck carrying traffic and cantilevers at the bottom of the box carrying pedestrian / cycle paths. The bridge was constructed segmentally, using a balanced cantilever construction method. It carried three lanes of traffic in each direction, with two pedestrian / cycle paths on cantilevers at the lower level. At 660 metres long, the Mount Henry Bridge was the longest road bridge in Western Australia at the time it was built.

The 2005 additions to the Mount Henry Bridge were constructed using an incremental launching technique, where 25-metre long segments were hydraulically jacked out onto piers from a casting bay on the southern embankment. The 26 reinforced segments were manufactured on site, and the launch of each segment took about five hours, scheduled two weeks apart throughout most of 2005. During construction, a combination of permanent and temporary piers were used. The appearance of the new bridge was designed to match the original bridge, with nine spans, the main navigation span at river level being 75 metres wide.

History

The north-south freeway system was planned by Professor Gordon Stephenson and Mr John Alastair Hepburn in 1955 as part of a plan to guide the long-term development of post-war Perth. Following the completion in 1959 of the Narrows Bridge, which had been planned independently of the Stephenson-Hepburn Plan, the remainder of the Freeway plan was adopted by the WA State Parliament in 1963. While the 1955 report had identified the location of the crossing of the Kwinana Freeway adjacent to Mount Henry, the 1963 Metropolitan Region Scheme showed the location as being adjacent to Deep Water Point. In 1967, following an objection from the City of Melville and consideration by the State Government of alternative crossing points, the location reverted to the Mount Henry side of the river, despite local concern about the environmental effect that this would have on the unspoilt shoreline of Mount Henry.

Ultimately, in 1975, Parliament approved the MRPA’s recommendation and the Metropolitan Region Scheme was amended to show the crossing on the eastern side at Mount Henry. Stage 1 of the freeway extension resulted in the completion of the Canning Interchange in 1979. The second stage of the project involved the construction of the Mount Henry Bridge and the extension of the freeway to South Street.

The Mount Henry Bridge was sensitively designed, and was constructed in such a way as to retain the foreshore of Mount Henry. The bridge was nearly twice the length of the Narrows Bridge, with separate pedestrian and cycle paths cantilevered below the main traffic lanes of the bridge. The construction contractor was Clough, and the project manager for Main Roads Western Australia was Geoff Smith. The official opening took place on 9 May 1982 with Premier Ray O’Connor and City of South Perth Mayor, George Burnett, in attendance.

In 2005, further construction work commenced on a second Mount Henry Bridge as part of the widening of the Kwinana Freeway and to accommodate a two-way railway line. This was part of a new railway line located between the opposing traffic lanes of the Kwinana Freeway; and extending from the Perth central business district to Mandurah. The new 15 metre wide bridge was built to the west of the original Mount Henry Bridge. It was designed to carry an additional three lanes of traffic, a break-down lane and a cycle and walking path. The two bridges overlap but do not touch, appearing as one continuous structure. The railway is accommodated on the western side of the original bridge.

Contractors were Leighton Constructions. The design team comprised Wyche Consultants, GHD and Coffey Geosciences. The new traffic bridge was opened to traffic in January 2006 and the southern suburbs railway commenced operation in 2007.

Integrity/Authenticity

High / High

Condition

Good

Uses

Historic Themes

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Disclaimer

This information is provided voluntarily as a public service. The information provided is made available in good faith and is derived from sources believed to be reliable and accurate. However, the information is provided solely on the basis that readers will be responsible for making their own assessment of the matters discussed herein and are advised to verify all relevant representations, statements and information.