Queensferry Crossing

Collaboration delivers UK’s most connected bridge

The landmark Queensferry Crossing Bridge in Scotland is almost certainly one of the most efficient, high performance bridges ever built, incorporating a complex array of utilities and communications equipment.

Constructed alongside the iconic Forth Road Bridge, the Queensferry Crossing replaces that bridge as the main road route north from Edinburgh, carrying the M90 motorway across the Firth of Forth.

Officially opened in September 2017, the Queensferry Crossing took six years to complete and forms the centrepiece of a major upgrade to the cross-Forth transport corridor in the east of Scotland. It represents an investment of more than £1.3bn and is truly world class, setting a number of national and international records, including the longest three-tower, cable-stayed bridge in the world.

A partnership between cable management specialist, voestalpine Metsec plc, leading M&E fixings supplier in Scotland, MEF, and lead M&E contractor, SES Engineering Services, has been critical in ensuring the delivery of the systems that will support the 2.7km road bridge and assure its safe and efficient running for decades to come.

A major logistical project

The bridge deck is constructed from 122 composite steel/concrete sections. 250-tonne steel sections were manufactured in China and shipped to Rosyth docks, where they were then prefabricated to incorporate all of the services and road surfaces.

The cable management systems supplied by Metsec were prefabricated into 424 modules by SES and then installed into each of the finished 750-tonne road section decks before being delivered to site by barge along the River Forth and craned into position to span between the bridge towers.

All of the cable management products used had to be pre-approved by the bridge authority, Forth Crossing Bridge Constructors. With the support of Metsec’s technical team, thermal extension couplers were designed and incorporated into the project’s cable management systems to help compensate for the movements of the bridge caused by temperature fluctuations, wind and traffic.

A collaborative approach

SES, explains, “Whilst we have a lot of experience in major infrastructure developments, the Queensferry Crossing was a once-in-a-lifetime project that demanded a highly collaborative approach to ensure we could meet and match the exact requirements to deliver all of the component parts of the bridge on time and in budget.

“MEF are part of the SES-approved supply chain and they selected Metsec not only because they were the best from a commercial and quality point of view, but because they were able to supply the cable management systems we needed in special sizes, vitally important in terms of minimising waste and ensuring ease of fit. Particularly important was their willingness to adapt the units to minimise the number of joints required. Everything was spot-on in terms of enabling the teams to fabricate and install each unit on schedule.”

voestalpine Metsec plc supplied hot dip galvanised cable tray and cable ladders cut to special lengths, the trays to 3.5m and the ladders to 6.9m. The finished modules assembled by SES hold a complex array of water management and cabling needs from lighting and power to traffic management systems, security, fire alarms, radio communications, structural health monitoring and building monitoring, all designed to give optimal control over the management and performance of the bridge.

“It’s a highly complex installation that effectively acts as the ‘brains’ of the bridge, controlling everything from the timing of the lights to maintenance planning, with a focus on optimising efficiency and communications not just on the bridge itself but on how it communicates with the traffic management systems that feed into it.”

Reliability and quality

Alastair Fairweather, at MEF adds: “This was a fantastic project to work on and much of our involvement has been down to the support we have had from Metsec. We have worked with them for several years now and we knew that their involvement would be vital to us winning this contract. The sizes needed were not standard, but their UK-based manufacturing facilities gave us the option to offer a flexible, high-quality solution to SES that we knew Metsec could fulfil and deliver on time and in budget. In fact, flexibility was critical not just in securing the project but in meeting evolving requirements as the project progressed over the12 to 18 months we were there.

“We put a lot of faith in partnering with Metsec for what was one of the biggest projects we have ever worked on and it has really paid off. The reliability and quality of service from the Metsec team has been as important as the quality of the products they supplied. The 55 micron hot dipped galvanised steel tray and ladder systems used will need to endure exposure to the elements for up to two years before being completely sealed-in under the bridge, and the high quality of the Metsec product will contribute to keeping the whole life costs of the project down.”

Jon Hillier, Director at voestapline Metsec plc cable management division, adds, “The Queensferry Crossing project was something we were keen to be involved in from the start. We knew we had the capability to re-programme our mill to allow us to manufacture the specified lengths of ladder and tray in a way that would fit perfectly into the required modules. Working with MEF meant that we were also able to offer the just-in-time capabilities needed to support the tight pre-fabrication scheduling for each of the bridge’s deck sections. It is great to see the bridge finished and fully operational, knowing that our products are supporting the complex systems that will drive the functionality of this impressive infrastructure showpiece and help drive transport connectivity in the region for years to come.”