New Cummins/Solaris CNG Urbino sighted

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Reports reach the CBW office of a Euro 6 Solaris being tested in the Darlington area

Residents of Darlington, County Durham, regularly see unfamiliar vehicles driving around the town as part of development work being carried out by Cummins’ Pilot Centre located in the town.

Following on from the New Bus for London, they have recently seen one of the lowest emission CNG buses undertaking trials, manufactured by Solaris Bus and Coach of Poland.

Cummins engineers based in the UK and Poland have been seamlessly working with Solaris to develop the latest version of the Urbino CNG. It has been fitted with Cummins ISL G natural gas engine, updated to meet Euro 6 emissions regulations. The work, the first Euro 6 installation for Cummins gas engines, has been carried out at the Pilot Centre, to be finalised with a road test in Sweden to confirm the engine’s performance.

John Burgess, General Manager for Cummins’ gas engine business, said: “We are pleased to work with Solaris on such an important project and develop a quiet, clean bus which will deliver benefits to the operator, the travelling public and the environment.”

Cummins has a strong relationship with Solaris, providing diesel and natural gas engines for its vehicles. The firm has already manufactured more than 400 Urbino natural gas city buses powered with Cummins’ current ISL G engine, certified to Euro 5 limits. These are in service throughout Europe.

The engineers equipped the Urbino with the latest hardware including a new exhaust catalyst and a closed crankcase ventilation system to meet the ultra-low emissions requirements of Euro 6. The bus was rigged with portable emission measurement equipment, including a temporary roof mounted exhaust pipe with the required sensors fitted. This enabled the bus to be driven on specific routes and the emissions measured to meet the regulations in line with the requirements of the UK Vehicle Certification Agency (VCA).

This Euro 6 project has driven more work for Cummins engineers, due to the different operating characteristics of a gas engine. The new on board diagnostic (OBD) regulations mean the engine electronic system had to be upgraded to measure exhaust emissions during vehicle operation. Once in use, the bus driver is warned if there is any malfunction in the vehicle emission systems.

The 8.9ltr Euro 6 ISL G natural gas engine is available from 250 to 320bhp for bus applications, with a peak torque of 1350Nm. It uses a combination of cooled Exhaust Gas Recirculation (EGR) with stoichiometric combustion, where fuel is burned completely. Cummins cooled EGR lowers combustion temperatures and reduces engine out emissions and noise. Stoichiometric combustion enables the use of efficient threeway catalyst aftertreatment.