Offsite working played a key role in the construction of Scotland’s iconic Queensferry Crossing project

The Queensferry Crossing project is Scotland’s largest infrastructure investment in a generation; the longest three-tower, cable-stayed bridge in the world forms the centrepiece of the Scottish government’s unprecedented £1.35bn upgrade to the cross-Forth transport corridor in the east of Scotland. Officially opened by Her Majesty The Queen in September 2017, this new iconic structure has been designed to complement the existing road and rail crossings and safeguard a vital connection in the country’s transport network.

Working for client Transport Scotland, the project has been led by the Forth Crossing Bridge Constructors (FCBC) consortium, consisting of HOCHTIEF Solutions AG, American Bridge International, Dragados SA and Morrison Construction. Given the 1.7 miles (2.7km) structure’s critical economic importance, FCBC’s decision to appoint national engineering specialist SES Engineering Services (SES) to its first-ever bridge project underlined the outstanding quality and ambition of the M&E contractor’s innovative offsite approach.

During this two-year project, SES’s role was to deliver mechanical, electrical and plumbing (MEP) services to the new replacement road bridge’s North and South approach viaducts, the cable-stayed bridge itself, its three towers and abutment buildings.

Offsite working on this project was not just a consideration, it was a necessity. With each 800-tonne deck section completed onshore then manoeuvred by boat from the port into place under the bridge, the use of offsite methods impacted every stage of SES’s project.

SES’s main delivery strategy on the Queensferry Crossing project was to maximise the amount of M&E services that could be installed within the individual CSB deck sections while remaining onshore. In order to achieve this goal, SES established its UK-first, project-specific offsite prefabrication facility in Rosyth to manufacture the containment and pipework service modules.

As the first MEP services contractor to achieve BRE-accredited BIM Level 2 Certification, SES and Prism provided true digital manufacturing functionality by marrying digital processes to limit waste, with the ability to create lean modules easily installed by engineers offsite in Scotland.

With the Scottish Prism facility up and running, the York-based manufacturing facility made the ‘flat-packed’ shrink-wrapped modules as lean as possible, reducing the logistical need for 60 lorries and 24,000 miles to just two lorries and the number of miles to 500. Pre-packing these modules within trays specifically enabled SES to easily slide each into position within a road deck section on the shoreline. This overwhelming commitment to offsite engineering dramatically reduced the need for working at height and saved more than 25,000 hours of labour, making the comparison to outdated on-site methods almost immeasurable. Initially manned by a team of Prism staff, over time the factory was handed over to an SES team of locally upskilled labour, breaking new ground for cost and time efficiency savings.

SES’s Business Director Scotland, Colin Walker, commented: “The crossing represents leading-edge, 21st century civil engineering. It’s a rare opportunity to be involved in building a new major infrastructure project of international significance.

“We knew this was the perfect opportunity for us to showcase the true capabilities of offsite technologies; and as part of a truly collaborative approach, this is a once-in-a-lifetime project designed with M&E at its core.”


Colin Walker   

Business Director Scotland

SES Engineering Services Ltd

Tel: +44 141 225 6777

Twitter: @Engineering_SES


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