The bridges supplied and installed by Cleveland Bridge were the Ruthvenfield Bridge spanning the road upgrades and the River Almond Bridge.

Project scope

Cleveland Bridge was chosen to supply and install two new bridges as part of the Perth Transport Futures Project. The overall objectives of this project being to improve air quality in the city centre, alleviate current and future traffic congestion, and provide essential infrastructure to support economic growth.

The upgrades to the A9/A85 junction that these will provide will enable much better traffic flow, significantly reducing transport times.

Solution

Cleveland Bridge has worked previously with Balfour Beatty on several successful projects, and was chosen due to our expertise, approach to collaborative working and exemplary health and safety record. As part of our scope we were required to supply, install, project manage and provide site services.

The River Almond Bridge

The 78m span bridge was painted in our extensive in-house paint facility. It was manufactured using our lean principles to eliminate waste and therefore supplied in nine sections, six of which were delivered to the North bank of the River Almond, using a temporary Bailey Bridge to cross the river. The Bailey Bridge had a weight limit of 98te, meaning each section was delivered in short lengths, prior to bolting together to form three x 43m long sections. These sections were then fitted with Decking and Cantilever Formwork by our client prior to installation into their final position by Cleveland Bridge, using a 1000te crane.

Cleveland Bridge UK Ltd. Cleveland House, Yarm Road, Darlington, Co. Durham DL1 4DE, UK

The 1000te crane then relocated to the south bank of the river and installed the final three sections. Each of those sections was 35m long, with the heaviest weighing 66Te.

The Ruthvenfield Bridge

This bridge carried a new road over an existing carriageway. It was installed during a night time closure to avoid day time closures of the strategically important route and the associated disruption to local traffic. Even though we were up against a challenging time scale to install, we still completed it with two days to spare, which delivered big benefits to the end client and local people.

Constructed from weathering steel, the Ruthvenfield Bridge had a length of 45m, supplied in three Paired Girder sections.

This enabled offloading each section alongside the live A9 by utilising specialist trailers, removing the requirement for mobile crane.

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This avoided the disruption of further road closures, whilst enabling our client to install the Decking Formwork prior to lifting the bridge into its final position, saving further road closures and reducing the risk associated with working at height.

Outcomes

Working closely with our client, we reduced the install time for both bridges significantly. Road closures during the night for the A9, when constructing The Ruthvenfield Bridge, were reduced from three nights to two. As a result, the road opened earlier. In addition, the River Almond Bridge was completed four days ahead of schedule.

Using our expertise we were able to reduce costs through value engineering and improve quality, delivering value to our customer and their end client. Waste material was significantly minimised, alongside the number of traffic movements required for transportation, by increasing the length of each girder dispatched.

The most critical KPI measure is safety; through strong leadership and working within Balfour's Zero Harm culture we gained a zero Accident Frequent Rate (AFR). The project was completed on time and within budget.

··-·clevelandbridge.com