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Crossrail: Raising the bar for a sustainable railway

When Crossrail Ltd. set out to make its new east-west rail line across London a model for sustainable construction on a massive scale, it chose Bechtel as its delivery partner. Together we are creating a comprehensive sustainability program that will become a benchmark for large-scale projects throughout the country.

Reducing the carbon footprint

Crossrail’s comprehensive carbon management plan is aggressive. After estimating that 15 percent of the project’s life-cycle carbon emissions would be attributable to construction, Bechtel set out to reduce the carbon footprint by 5 percent—all without increasing costs. To date, we have exceeded these goals—cutting emissions by nearly 10 percent.

Working closely with our project partners, we introduced several innovative plant and equipment technologies in select areas of the project to further reduce carbon impact.

For example, our team has used diesel-electric hybrid excavators that consume 25 percent less fuel and produce 30 percent less carbon emissions than conventional excavators. We also substituted nonpetroleum biodiesel fuel in generators used to operate cranes, selected LED site lighting that consumes 47 percent less energy, and relied on zero-emission hydrogen fuel cells as portable power sources.

By monitoring digital dimming, movement detection, and photocell light equipment, the team was able to provide a continuous real-time picture of consumption that helped to promote operational efficiencies. The energy needed to run services for the full design life of Crossrail—120 years—is expected to account for 85 percent of overall carbon emissions, most of which will come from the trains. The team is reducing emissions by focusing on design features to improve energy efficiency, including:

  • reducing the weight of passenger cars
  • establishing targets to reduce energy consumption
  • using regenerative braking
  • placing smart controls in passenger cars for lighting, heating, and air-conditioning

Benchmarking for the future

Bechtel has managed Crossrail’s adoption of two widely recognized sustainable design and construction assessment methods and accreditations:

  • Building Research Establishment Environmental Assessment Methodology (BREEAM)—the UK standard for best practice in low-carbon and low-environmental-impact design, construction, and operation.
  • Civil Engineering Environmental Quality (CEEQUAL)—a comprehensive sustainability rating system for assessing environmental, economic, and social performance.
The Crossrail project represents the first time that the BREEAM standard has been applied to evaluate underground stations, and it is establishing a benchmark for other stations. All of our station designs have achieved Very Good ratings under BREEAM, and our tunnels, portals, and shafts have attained an Excellent rating under CEEQUAL. Both of our completed structures have achieved a rating of Excellent under CEEQUAL.


With more than 250 machines spread across nearly 40 construction sites, Bechtel and Crossrail achieved an 85 percent reduction in particulate emissions on Europe’s largest construction project. Through a combination of new engine performance standards, retrofitting of particulate controls, hybrid technologies, and training, the project has significantly reduced particulate emissions. 

Moreover, Crossrail was recognized as the first infrastructure project in the United Kingdom to adopt strict emissions controls across all of its work sites. It has also introduced newer, cleaner machines across London and encouraged suppliers to upgrade their equipment. The success of this program on Crossrail has helped to support the Greater London Authority’s intent for a wider- scale introduction of these controls.

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