Taking steps to decarbonise the railway

06 Jul 2022

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Shane McEntee – our Health, Safety and Sustainability Manager for Rail at Amey – gives us his insight into our Kentish Town Track Stabilisation project that saw Shane and his team use the RSSB’s Rail Carbon Tool (RCT) to quantify carbon emissions during design, construction and at project completion -- a new, environmental approach to the way we undertake construction and maintenance projects on the tracks.

“Decarbonising the railway is a strategic objective for many within our sector – exploring new and innovative ways to reduce our environmental impact through our working practices.

“Kentish Town was a three-phased project that gave us that opportunity to trial new ways of working and evidence real success. Working with our integrated design team, Amey Consulting, and our construction capability, we’ve been able to assess the whole life carbon associated with a project using RSSB’s Rail Carbon Tool (RCT).

“This approach is the first and most significant step in understanding the pathway to fully decarbonise the railway, while also reducing the impact on local air quality by diesel emissions from on-site plant and equipment. With the focus of World Environment Day on bringing about positive change through transformational impact and behavioural change, we wanted to share our carbon reduction journey to inspire others to look at railway construction differently.

The Project

“There were many elements to the Kentish Town Track Stabilisation project. Works included repairing an existing concrete track slab within the portal of Overbridge 17 (OB17) and replacing a concrete track slab with ballasted track. 

“As designer and principal contractor for the works, Amey was presented with an opportunity to do things differently: reducing carbon at each phase of the project from the initial inherited design through to completion, and then be able to demonstrate carbon reductions in clear increments over the lifecycle of the project.

“The RCT was used to calculate the embodied carbon at each stage of the project and as a method for capturing carbon reductions. The scope of the carbon assessment included calculating carbon across six key areas: materials (embodied carbon), materials (transportation to site), waste (embodied carbon and transport), fuel use onsite, plant and equipment (transportation to/from site) and employees (travel).

“Across these key areas, we were able to make 14 significant changes to either the design or construction methodologies that reduced the carbon footprint of the project. Through making these changes, it was calculated that 89 tonnes of CO2e were saved, representing a 32.36% carbon saving against the initial design and scope of works.

“This falls in line with Network Rails (NR) priority to deliver a low emissions railway and the target to get to net zero by 2050, as identified within the NR Environmental Sustainability Strategy.

Measuring success

"The RCT can be used as a tool to provide a snapshot in time of the total carbon footprint of the project, which on its own provides an arbitrary figure, and one that is difficult to measure success against. However, to gain maximum insight for the Kentish Town project, we set a target of 20% to reduce carbon emissions across the design and construction stages of the project.

• A carbon assessment was completed based on the initial design and methodologies used by Amey during the two previous phases of the project. This gave a total estimate of 275 tonnes of carbon that would have been produced had the project been undertaken based on the scope of the assessment for the initial design.
• The project then identified design changes that were implemented to reduce carbon and modelled these into a carbon assessment for the design phase to display an estimated 5.45% reduction in carbon, saving approximately 15 tonnes of carbon.
• Had the project been completed based on information at the detailed design phase, it would have produced an estimated 260 tonnes of carbon.
• Finally, incorporating carbon reductions that were made during the construction phase, a carbon assessment was completed to calculate the final carbon output for the project post-completion. It was calculated that there were 186 tonnes of carbon produced as a result of the project, representing a further 28.46% reduction from the design phase.

“In total, the project was able to successfully demonstrate a carbon reduction at each phase of the project of 32.36%. This was a significant improvement on the initial targeted reduction of 20%.

Counting the commuter cost

“Another key component of the carbon assessment included calculating the emissions associated with employees commuting to and from work. To reduce the contribution from commuting to the project’s carbon footprint and address the potential risk of fatigue, a minibus and hotels were made available for some employees. We connected the RCT to our online Fatigue Management System (Datascope) which enabled us to look at commuting patterns and arising carbon emissions for those intending to work over the Christmas blockade.

“There were also more intangible successes helping to calculate the carbon footprint of the Kentish Town project. The scope of the carbon assessment was complex and required a multi-disciplinary approach to provide information on plant numbers, shift working times, materials ordered, and waste produced. A truly collaborative effort by all disciplines across the project was crucial to being able to undertake the assessment. Without this, the assessment could have not been undertaken, and it’s a real testament to the project team and their engaged supply chain.

Successfully reducing carbon

“We were able to utilise varying design and construction methodologies to successfully achieve a reduction of carbon during each phase of the project. The top 5 contributors to reducing the carbon were:

1. Avoiding the use of generators and instead connecting welfare to mains electricity supply – 26%
2. Undertaking the dig in a single-stage instead of two separate stages – 20%
3. Designing out a requirement for removing a portion of track slab – 14%
4. Reducing employee commuting distances – 14%
5. Using MSF (mineral conveyor and storage unit) wagons to unload materials from engineering trains – 11%

“An initial hot spot analysis was also done on the RCT to identify the items that produced the most amount of carbon. These items were then reviewed to see if any improvements could be made to reduce their carbon footprint in the future. For example, we identified that the transport of plant to and from site accounted for 17% of the carbon for the project. If all plant was sourced within a 50km radius of the project, a further 19 tonnes of CO2e could have been avoided – learnings that we’ve shared wider at Amey to maximise future carbon reductions.

Delivering carbon ambition

“At Amey, we’re committed to achieving long-term environmental sustainability by reaching Net Zero carbon emissions by 2040. This target includes all emissions associated with Scope 1, 2 and 3 greenhouse gases – a challenging target some may say.

“At Kentish Town, we had a clear ambition for undertaking the carbon assessment and recognised early on that having a role as the designer and the principal contractor would provide an opportunity to deliver carbon reductions at both stages of the project. The Conference of Parties (COP26) in Glasgow during November 2021 and the launch of Amey’s Roadmap to Net Zero positioned the subject of carbon reduction to the forefront of the project team’s objectives.

“There was leadership buy in from the start of the project, with the client as well as buy in from across the supply chain, who all provided information to complete the assessment and work towards our target of achieving a reduction of 20%.

“Once the project was completed, we engaged with Network Rail to complete the assessment and share the output for wider circulation across the industry ensuring that the data inputted and results are accessible to the wider industry – sharing best practice so others can benefit too.

Adoption across the rail sector

“The Kentish Town project is considered to be at the forefront of the movement to using the RCT through displaying transparent carbon reductions over the lifecycle of the project. On this occasion the carbon assessment undertaken assessed a 10-day blockade, but the RCT is designed to be able to calculate the carbon footprint of a project over a much longer period and for a variety of work packages."

“With the lessons learnt from our Kentish Town project, we’re able to take these forward and upscale onto larger works, locking in sustainable behaviours while paving the way for more notable carbon reductions and the decarbonisation of the railway.”

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