Hegigio Gorge Pipe Bridge

The Hegigio Gorge pipeline suspension bridge was developed to carry oil pipelines across a 500m deep gorge in the PNG Southern Highlands. The bridge spans 470m and sits within a remote, difficult-access location where standard construction methods were not practical.

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The bridge comprises three catenary cables, with two horizontal cables and one vertical cable connected by wire stays and cross beams. Two parallel runway beams provide access along the bridge by trolley. The main cable connects to a 33m high A-frame tower at the southern abutment and a 4m high tower at the northern abutment.

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Key Project Elements

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Temporary Works and Construction Access

• Temporary platforms fixed to the top of the south tower
• Two 12-storey access towers
• Access tower design to support raising of the south tower A-frame
• Purpose-designed reeved lifting system

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Bridge Launching and Cable Works

• Controlled restraint system for launching the bridge
• Structures to form, position and launch the horizontal cables
• Guide tower, cable reel and deflector towers
• Horizontal cables comprising 70 strands each

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Pipeline Installation

• Trolley system to pull pipelines across the bridge
• Personnel access trolley for installing pipe clamps at the cross beams

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The project required innovative temporary works, controlled launching methodology and practical construction access solutions. The engineering was shaped by the remote location, limited abutment access and the need to safely construct a long-span pipeline bridge across a deep gorge.