Tuesday, 24th May 2016
  • Rhian Locke (Principal Consultant )

Sustainability lessons learnt from Crossrail

Before joining Temple Group, I was the EMS and Performance Manager for Crossrail, working in the client team from October 2011. Crossrail was an exciting and ambitious project to work on and reducing the environmental impacts of Crossrail’s construction was the main focus of my role; it involved integration and collaborative working with Tier 1 contractors. I joined Crossrail during the end of the enabling works before tunneling began in 2012 and there were numerous complex and interesting issues to address during that time; namely how to tunnel under the Thames whilst undertaking environment mitigation. Increasingly the emerging legacy of Crossrail is being used to inform other major infrastructure schemes.

Based on my experience the main lessons that Crossrail can pass onto other projects include the following:

Sustainability governance and performance assurance

I provided the lead environment input to Crossrail’s performance assurance process, which has been used as a key legacy item to pass onto other high-profile major projects such as HS2. Reducing the environmental impacts of Crossrail was the principal purpose of the Environmental Minimum Requirements (EMR), which were recognised as environmental best practice. Performance assurance appraisals were successful in driving improved environmental performance from EMR compliance to world-class in a number of instances.

Effective stakeholder engagement

Control of noise and vibration was, and continues to be, one of Crossrail’s biggest challenges due to the close proximity of work sites next to residential and commercial properties. In order to manage this, Crossrail collaborates extensively with Local Authorities, operates under Section 61 consents and utilises Best Practical Means. Such mechanisms included adopting quieter methodologies such as drill and burst. One of the key lessons learnt from Crossrail was that early engagement with stakeholders is essential. Being proactive after receiving complaints and enquiries helps ensure effective working relationships.

Measurement of best practice

Another aim was reducing emissions from non-road mobile machinery where practicable. Since 2010, Crossrail has been working with its Tier 1 contractors and its supply chain to use plant with either Euro III (b) or IV engines and if not compliant, the engine had to be fitted with an after treatment device. This was a direct contract requirement from the EMR, which helped to drive air quality performance across the project.

Crossrail set targets of 95% diversion from landfill for excavated material and 90% diversion from landfill for construction waste. 7 million tonnes of material was excavated during construction and 98% of excavated material was beneficially reused. Nearly 80% of material was transported to end sites by rail and water, significantly reducing the lorry journeys. 3 million tonnes of material was used to create a 1,500 acre wildlife habitat at Wallasea Island in Essex.

The project also pioneered an approach to understand the entire carbon footprint of Crossrail with a particular focus on construction energy. This led to an average construction carbon dioxide reduction of 11% against a target of 8% across the programme.

 Supply chain integration

 I believe the key sustainability success of a project like Crossrail is to include stringent requirements in the Works Information and to develop a robust methodology like the Supplier Performance appraisal to measure performance across a project. Throughout the duration of Crossrail’s enabling and main works, it also became apparent that contract information needs to be clear and transparent to avoid ambiguities.

It is essential that leadership are bought into environment and sustainability policies and that all interested parties (i.e. the Client and Principal Design Partner, Design Consultants and tier 1 Contractors) critical to the success during the delivery of the works, are fully integrated and collaborative to warrant a joined up approach. This extends to civils and station contracts and system-wide contracts to ensure they are integrated throughout the process.

Investment in innovation

Innovation is also important across the supply chain to increase environmental performance by identifying approaches and materials which will help reduce costs and environmental impacts. Sustainability principles will need to be embedded throughout a project to contribute to long term challenges.

Alignment of client aspirations

Alignment of objectives with client aspirations is also essential and at Crossrail, early engagement with the supply chain was essential to ensure that client goals were aligned.

Crossrail has set up a learning legacy website ( to capture lessons learnt from the project.