LPG Buses Benefit Chester

Supported by government grants and tax benefits, the use of environmentally friendly alternative fuels in vehicle fleets across the UK has become well established. A range of alternative fuels have been trialed, including electric, LPG (liquefied petroleum gas), and CNG (compressed natural Gas), and LPG has consistently emerged as the most successful and practical of these fuels, offering efficiency as well as significant environmental and cost benefits. In recognition to these benefits, a number of bus operators have now introduced LPG powered buses onto their fleets, including Arriva Passenger Services which runs Calor Autogas powered buses in Chester, Watford and Glasgow.

Arriva Cymru, part of Arriva Passenger Services which runs 75,00 buses nationwide and employs around 25,000 staff, has successfully run four Calor Autogas buses on one of Chester's busiest park & ride routes since February 1999. Arriva was awarded the contract for the operation of the route from Cheshire County Council, which is extremely pro-active in the battle to reduce levels of air pollution in the historic walled city.

Prior to putting the route out to tender, the council had worked alongside Chester City Council to fund a 20-month trial of an LPG bus on the established park & ride network in Chester. The objectives of the scheme were to:

• Place clean buses in the public eye and encourage the link between travel behaviour and local air quality;
• Enable bus operators to experience clean buses with minimal perceived commercial risk to themselves;
• Set up a realistic evaluation against diesel equivalents; and
• Generate conditions which would assist the adoption of more clean buses in future

The trial scheme was so successful that the council decided to support the increased use of LPG buses on the park & ride route, which runs a service every ten minutes from the south of Chester to the city centre. Arriva Cymru won the five year contract with its proposal to operate four Calor Autogas powered buses on the route. The new 12-metre DAF buses, which boast a purpose built chassis and run solely on LPG, are ultra modern and meet all requirements for low floor accessibility and park & ride seating.

David Lewry, policy and projects principal officer at Cheshire County Council, commented: "One of the councils' key objectives was to reduce the levels of pollution on key routes within Chester, to help preserve historic aspects of the city and improve air quality for residents and visitors. The Wrexham Road park & ride scheme is extremely popular, with each bus carrying around 70,000 passengers a year over 45,000 miles, so the potential environmental benefits of using a cleaner burning fuel on the route are quite clear."

The emissions from the model of LPG powered DAF bus operated by Arriva have been evaluated by independent consultant Millbrook Proving Ground. The study revealed that emissions of carbon monoxide, nitrogen oxides, hydrocarbons and particulates at the exhaust pipe were dramatically lower than those of a bus running on ultra low sulphur diesel - proving that the Calor Autogas buses running in Chester contribute to reducing harmful emissions in the city.

Whilst reducing pollution was a key consideration in the operation of LPG buses, running costs were also taken into account. Although bus operators can reclaim some of the duty on diesel, Calor Autogas is still around 8 per cent cheaper than diesel. In addition, oil change intervals of the LPG engines are increased and performance of Arriva's buses indicates that the engines will last at least as long as their diesel counterparts, and be no less reliable.

Although the capital cost of the LPG buses is greater than that of the equivalent diesel models, the government funded Energy Saving Trust Powershift programme provides a grant of 75% of the cost differential. In conjunction with the cost savings on fuel, this means that whole-of-life costs for LPG buses are roughly equivalent to those for diesel - a clear incentive to local councils,bus operators and other organisations considering ways in which to contribute towards an improvement in air quality.

LPG - what is it?