Joining Forces To Reduce Emissions

Joining Forces To Reduce Emissions

Discover how we partnered with HJS Emissions Technology back in 2020 to modify 637 National Express buses within the West Midlands fleet in readiness for the emission zone regulations coming into force in the Birmingham city centre that year.

Customer Profile

Customer Name: National Express West Midlands

About Customer:National Express West Midlands is a bus operator in the West Midlands that operates services in Birmingham, Dudley, Sandwell, Walsall, Wolverhampton, and Solihull, as well as limited routes outside of the general area of Birmingham, such as the X1 to Coventry, or the 144A to Bromsgrove.
Sector: Bus and Coach
Location: UK – West Midlands
Application:Cooling Modules


  • Electric Fan Cooling System


In 2020, we partnered with HJS Emission Technology to modify 637 National Express buses within the West Midlands fleet.

In readiness for the emission zone regulations coming into force in the Birmingham city centre that year; the joint venture saw EURO 3, 4 & 5 rated buses converted to Euro 6 CVRAS standard for compliance in the Birmingham, Coventry, Walsall and Wolverhampton areas.

Our Solution

GTS employees stand in front of buses at Grayson Thermal System's Servicing Centre after converting mutliple vehicles to make them COVID-safe

Both GTS and HJS technical departments worked closely to find the very best solution for optimisation of these National Express West Midlands vehicles and fitted our innovative GTS Electric Fan Cooling System and HJS SCRT Real-Blue after-treatment system with integrated telematics over a rigorous schedule of 20 buses per week up until the end of that calendar year.

Ian Hateley, GTS Group Aftermarket Director, explained: ‘Our Electric Fan drive system reduces the parasitic load on the engine, therefore aiding the management of thermal performance from the charge air system. This in turn helps to increase exhaust pipe temperature, thus aiding the reduction in emissions.’

The HJS-supplied after-treatment system monitors emissions through the onboard telematics. This broadcasts the status and performance of the HJS system in order to ensure the highest level of in service system reliability.

Fleet operators are under an immense amount of pressure to maintain service levels and reduce their environmental impact in order to comply with Clean Air Zones (CAZ’s). The HJS SCRT provides operators with a cost-effective retrofit solution for CAZ compliance with the ongoing system “real-time” status and performance available to view using the HJS Remote Emission Monitoring (REM) system.


This represented an element of significant investment into ‘clean air’ projects throughout the West Midlands with National Express West Midlands buses becoming amongst the cleanest in the area in 2020 (with the fleet being 80% Euro VI by January 2021 and 100% Euro VI by April 2021).

Not only were these adaptations good for the environment, but they also served to provide over 25 extra jobs in the local Birmingham area through GTS employment, with additional positive impacts being seen further afield too.

This was a great continuation of a 20-year relationship between National Express West Midlands and Grayson Thermal Systems, with both parties pleased that the HJS team were on-board to see this project through to successful completion.

Key outcomes

Successful fleet conversion

637 National Express buses within the West Midlands fleet successfully converted

Reduced fleet emissions

National Express West Midlands buses became amongst the cleanest in the area

Stand out collaboration

Project saw National Express West Midlands, Grayson Thermal Systems, and HJS come together to successfully complete project

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