A product-led approach to bridge design

By taking a modular approach underpinned by digital configuration, Laing O'Rourke has managed to significantly reduce the time required to design and deliver bridges, civil engineering leader Phil Robinson told GIRI members at February’s members’ meeting.  

This has required a reordering of conventional design processes, said Phil. “You can’t build a digital tool to configure products unless you know what the products are, and that requires upfront work. There’s no point approaching this on a project-by-project basis, and we need the support from clients and stakeholders to make it work efficiently.”

He explained: “In traditional bridge design, we take one bridge in one location, and ask a designer to explore the options based on the requirements of that bridge. Then we make a selection from the available options, usually the cheapest, and at some point someone comes along and asks us to consider modular options to save time. But by then it is too late in the design process. The geometry is locked in and approvals are in place.”

In a product-led approach, however, a product library is generated, and products and their association configurations are pre-approved by clients. “This then enables us to look at multiple locations across a scheme and rapidly explore options to find the best solution for that bridge. We can make decisions informed by actual data and see the impact our decisions have on cost.”

Laing O’Rourke has developed a kit of parts for bridges. This involved looking at all the constraints in the construction and manufacturing process and what needed to change to enable the business to deliver for clients. “We also looked at how we could automate as much as possible in the actual construction and how to standardise and create the minimum level of variation that is sufficient for our requirements. That means understanding what we currently have and what investment is required to improve it.”

He explained that it was also necessary to consider all the interfaces. “We had to understand the in-situ components to allow us to run fast when we bring all our off-site manufactured products together. It’s not just about these off-site elements, but how they integrate with the on-site elements.”

What Laing O’Rourke developed was a kit of parts that provides various options so the business does not have to re-invent the wheel each time it comes to deliver a bridge. This product-led approach maximises the opportunity for repetition and efficiency during manufacturing, while offering enough flexibility to configure the products to suit the geometry required for each specific bridge location.

Phil shared an example of a modular abutment assembly for HS2 that took a team of six multi-skilled people five days to construct as opposed to the traditional approach which would take a team of 10 skilled labourers eleven weeks.

“We completely re-engineered the bridge down to the reinforcement detail. We used fewer people and constructed it in less time by using repeatable processes.” Fewer people on the site also improved safety, and the components were manufactured in a warmer, drier environment, improving quality while reducing the opportunity for defects. In addition, carbon was reduced by 8%.

 “We are currently working on an M25 scheme with Balfour Beatty, and by delivering bridges this way we have been able to reduce their programme by six months.”

The approach is underpinned by a digital bridge configurator tool that sits at the heart of Laing O’Rourke’s operation. It was developed to deliver single-span concrete bridges using a modular product set. It is accompanied by a design guide for consultants on how to design using these components, an installation manual for component assembly, and an approved installer scheme to drive consistency in the quality of the delivered asset.

Phil explained that this digital toolkit enables rapid optioneering and exploration of design. The tool is dynamically linked to cost and carbon data, allowing informed decisions to be made during the design process. 

“Within two hours of receiving information from the client, we can generate a validated 3D model, associated drawings cut directly from the model, automated reports for client approval processes, and automated costing measured directly from the model. We are getting through quality assurance in weeks as opposed to months, and we think that with the tools our consultants use alongside ours, that we can start to reduce the duration of bridge design by 50%.”

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