Carbon management in action

11 March 2022
Ariel view of a straight road surrounded by trees
Amey Consulting’s commitment to carbon reduction is underpinned by technology, best practice and a culture that encourages creative thinking

Climate change is a pressing concern for us all as carbon dioxide levels and other greenhouse gases in the atmosphere continue to rise. The UK government has adopted a target of net-zero greenhouse gas emissions by 2050, and the built environment and infrastructure industries – both significant contributors to the UK’s carbon footprint are actively leading on creating innovations, strategies, and action to reduce carbon at source.

According to the UK Green Building Council, the built environment – including infrastructure such as roads and rail – contributes around 40% of the country’s carbon footprint. Recent research by the Institution of Civil Engineers shows that carbon emissions from UK infrastructure fell by almost a quarter between 2010 and 2018. However, while operational and user carbon showed a decline, there has been a 60% increase in capital carbon. This suggests that in order to meet the net-zero goal, the industry needs to address the carbon associated with the creation of new assets.

Many organisations involved in infrastructure development are building their sustainability strategies around science-based carbon reduction targets. These have been established by climate change scientists to restrict the rise in global temperature to below 2 degrees Celsius or, more ambitiously, 1.5 degrees Celsius. Network Rail recently became the world’s first railway company to commit to the more rigorous target.

Amey Consulting has developed its own comprehensive strategy to work towards zero carbon on all our projects. Carbon management is not an add-on to tick the sustainability box – it is central to every discipline involved in engineering design. While carbon assessment is mandatory on all projects worth more than £1 million, we seek opportunities to reduce carbon as a matter of course on all our contracts, regardless of value.

Our staff are trained in the use of the Rail Carbon Tool, a web-based resource that provides information about embodied carbon associated with products and activities related to rail infrastructure projects. We are building our own product library containing detailed carbon calculations for use with the tool. By linking this information to our CAD models, we can make much more accurate carbon assessments of our designs. More data is added after each project, expanding the knowledge base and increasing our ability to make decisions that reduce our carbon footprint.

However, information is only part of the story. Creating a culture of awareness, in which all project members are alert to opportunities to reduce carbon emissions, is equally important. We have added a new section to our internal Engineering Management Manual (EMMa), introducing a formal carbon analysis and reporting process within multidisciplinary teams. To support this, we have set up a working group known as the ‘Carbon Army’ whose members carry out peer-to-peer training and discussions aimed at promoting carbon awareness and best practice.

Our designers and engineers are expected to go beyond basic environmental considerations and think about carbon reduction as an integral aspect of every project. They are trained to apply the Carbon Emissions Reduction Hierarchy, which provides rail-focused guidance on minimising emissions: build nothing, build less, build clever, build efficiently, and compensate for ‘unavoidable’ emissions. Where some form of manufacturing is essential, our people think creatively to minimise environmental impact.

We have created a forum on our internal Carbon Management website where people can share knowledge and advice and report good practice. We have a scheme that rewards novel ideas and suggestions for reducing carbon. Project teams can tap into this resource to identify effective approaches that can be shared with clients. The site includes an active and growing library of tried and tested low carbon and energy efficient products.

Carbon management in action

Amey Consulting is pushing the boundaries of what can be done to drastically reduce the carbon footprint of typical railway electrification schemes in the solutions being developed on the Core Valley Lines (CVL) project in Wales. Our project teams follow the carbon hierarchy, but given the aged infrastructure of the network, it is not always possible to avoid new construction. Our designers have accordingly taken a smart approach, using Amey’s sophisticated modelling tools to minimise the need for additional infrastructure.

For example, we introduced permanently earthed sections (PES) to avoid track lowering or bridge deck modification to 55 Victorian bridges that lacked the necessary clearance for live overhead cables. Our design allows for hybrid trains to stop drawing current from the earthed section of cable under the bridge and switch to battery power, reverting to overhead current once safely through the bridge.

This deceptively simple solution avoided the significant carbon emissions that would have accrued from raising bridges and lowering track to create the necessary clearances. Furthermore, our advanced power modelling has helped to optimise the use of battery power by the trains, removing operational carbon from the system.

Another example is our success in minimising the new infrastructure required to renew the signalling power supply system on the Great Western route in Somerset and Devon. Following a power modelling exercise, the Amey team identified options that avoided the need to manufacture and install new principal supply points (PSPs) and distribution interface transformer assemblies (DITAs), as the design was able to make better use of existing equipment and assets.

The project demonstrates the value of the Rail Carbon Tool when used proactively. Since the product libraries available at the time were limited, the team constructed its own product carbon packages based on information from suppliers and construction teams. As a result, the designers were able to make detailed carbon assessments, gaining a realistic insight into the carbon impact of materials. This included the extraction and processing of raw materials into products, machinery and fuel used during site construction, transportation of materials and products to work sites, and transportation of staff.

A Resource Efficiency Workshop was held to identify opportunities to cut down on the materials used, design out waste and introduce recycled and more sustainable products. One positive outcome was the replacement of environmentally unfriendly concrete cabling troughs with glass-reinforced plastic versions, which are less carbon intensive and lighter and cheaper to manufacture and transport. This option saved significant kilos of equivalent CO2 compared to the conventional solution.

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