HS2 shares emission reduction insights
15 November 2022
HS2 Ltd has announced this year’s winners of a competition to share insight from Britain’s largest construction project with the wider UK infrastructure industry.
The HS2 Learning Legacy initiative sees the publication of lessons learnt from across the project, including good practice and innovation. The five winners of the 2022 Technical Paper competition include a project reducing emissions in construction through non-road mobile machinery (NRMM) retrofit, involving HS2, Balfour Beatty VINCI, Imperial College London and the exhaust after-treatment specialist Eminox.
This report addresses how to reduce emissions and keep existing machinery in use for longer and extend the utility of the embedded carbon and the financial investment in those assets.
The winning submissions have been published on the dedicated HS2 learning legacy website.
The project recognised that many contractors would need to replace or re-power older plant, which can be both a slow and costly process especially for large machines with the longest lifespan within a fleet, such as crawler cranes and piling rigs.
HS2 worked with UK manufacture Eminox Ltd, HS2 Main Work Civil Contractor (MWCC) Balfour Beatty (BBV) and Imperial College London to develop, trial and test an NRMM retrofit solution which adds after exhaust technology to existing engine systems on plant machinery to upgrade them to meet or exceed the latest EU Emission Stage leading to cleaner air around construction sites.
The report authors say that, since most NRMM engines have relatively longer life spans than on road vehicles, it is not uncommon to find machinery with older engines being used in the construction industry, which do not adhere to the current emission standards set by either the Greater London Authority (GLA) or HS2.
HS2 have set minimum engine emission requirements for all NRMM with an engine power of between 37kW and 560kW. From 01 January 2022, these include Stage V within the Central Activity Zone, and Stage IV within Greater London and the rest of the country.
Eminox Retrofit SCRT emissions systems are certified by the Energy Saving Trust, through the NRMM Retrofit Accreditation Scheme (RAS) to upgrade existing engines to meet EU emission Stage V equivalence.
The system comprises a DOC (diesel oxidation catalyst), DPF (diesel particulate filter), SCR (selective catalytic reduction), ASC (ammonia slip catalyst) catalyst converters, and finally, a slip of catalyst to deals with the ammonia residue and ensure clean emissions are discharged from the exhaust tailpipe.
Telematics systems are incorporated for in-service remote monitoring and maintenance.
The Eminox solution was fitted to a BBV Stage IIIA Junttan PM20 piling rig and a Stage IIIB Bauer BG30 rotary rig to demonstrate the upgrading of both a medium and large engine application.
The report says the results indicated that the solution was successfully able to reduce NOx and PM concentrations in line with the EU Stage V expectations.
