Bus innovation saves fuel
Using a smaller diesel engine, in conjunction with an electric engine, has major fuel-saving benefits for frequently-stopping buses. FRANK BEETON tells of Volvo Bus Corporation’s investment in this technology before providing an update on the latest news in the Indian bus industry.
Following several years of research and development, Volvo Bus Corporation has announced the commencement of hybrid driveline bus production. The first products that will be offered to the market are the 12 metre 7700 Hybrid bus, which is being built at the Wroclaw plant in Poland, and the B5L Hybrid double-decker chassis being manufactured at Borås in Sweden. Bodies for the latter unit will be provided by Northern Ireland’s Wrightbus.
The driveline technology employed in these units is of the “parallel hybrid” type, in which a smaller-than-normal diesel engine is used in conjunction with an electric motor. The vehicle can be propelled by either of the power sources independently, or both in unison. Regenerative braking energy is recovered and stored in a battery, and is fed to the electric motor to provide power for acceleration. The diesel engine is automatically switched off when the vehicle is stationary and the electric motor is only used for initial pull-off. Thereafter the diesel kicks in when road speed reaches about between 15 to 20 km/h.
Field tests of this technology (under real operating conditions) have reflected fuel-consumption benefits of between 25 and 35%, depending on the frequency of stops. It turned out that higher frequency in stopping resulted in greater savings. UK operator Arriva has been trialing hybrid buses since 2007, and took delivery of six Volvo B5L Hybrid double-deckers a year ago. They operate on London route 141, between Palmers Green and London Bridge, where buses are required to stop every 150 metres on average, and they only travel an average speed of about 8 km/h. These vehicles have returned fuel savings of more than 30% when compared to normal diesel buses operating under the same conditions.
Hybrid buses currently account for around 20% of the city bus market in North America, with the proportion steadily increasing. This trend has been encouraged by a higher level of subsidisation than currently available to European operators. Volvo believes that the ready commercial availability of hybrid vehicles, using a high proportion of standardised components, will help to advance the cause of hybrid driveline vehicles on the Continent.
With the increasing internationalisation of the Indian vehicle-manufacturing industry, many of the domestic players have chosen to establish offshore partnerships. This opens up opportunities for the transfer of technology and production processes. This has applied equally to the bus sector, and the most significant developments have involved Tata Motors. Tata started the process of progressively acquiring Spanish coachbuilder Hispano Carrocera in 2005, and setting up a global bus-development unit in Zaragoza. They also subsequently established an Indian-based production joint venture with Brazilian bus giant, Marcopolo.
Now, Tata’s largest domestic competitor, Ashok Leyland, has embarked on a similar exercise to progress its Global Bus programme, and, in doing so, has perpetuated the long-standing relationship between the commercial vehicle industries of India and the United Kingdom. In terms of a recently-signed agreement, Ashok Leyland will acquire a 26% stake in UK bus manufacturer, Optare, thus gaining access to that company’s mid-size and full-size city bus technology. The two companies intend to work together in developing new products and markets, and co-operate in optimising supply chain management.
There are interesting linkages between the histories of both companies in this new partnership. Ashok Motors was originally established in 1948 to assemble Austin motorcars in India. In 1955, the company’s name was changed to Ashok Leyland, and it commenced the manufacture of Leyland commercial vehicles, leading to the introduction of local versions of the Comet, Tiger and Titan bus chassis. After the demise of former equity partner, British Leyland, Ashok Leyland entered into new technology-sourcing arrangements with Hino Motors of Japan and Iveco of Italy, and is currently involved in partnerships with Nissan and John Deere.
The Optare Group was originally founded in 1985 by a group of former employees of the historic North English coachbuilder Charles H. Roe, Limited, after that operation had been acquired, and subsequently closed down by British Leyland. Optare Plc specialises in the manufacture of a comprehensive range of integrally-constructed buses and coaches, and also provides single- and double-deck bodywork. They also provide a variety of passenger-carrying modification “packages” for popular dedicated bus chassis models and integral panel vans. The current product range is made up of the Solo, Versa, Tempo and Olympus models, and Optare is represented in South Africa by Busmark 2000 of Randfontein.
Ashok takes 26% stake in Optare
Ashok Leyland Ltd, the Indian subsidiary of the London-based Hinduja Group, says that it has agreed with Optare plc to take a 26% in the UK bus maker. The deal is worth some $7.5m (£4.8m). It will give Ashok access to Optare’s technology, including its successful range of mid- and full-size city buses. In return Optare will get access to Ashok’s lower-cost suppliers and new export markets. The two firms will work together on product development. Optare has an £80m turnover and an enviable reputation for low carbon developments; its new electric bus has already won several orders across Europe. Ashok, itself a major bus maker, will put two directors on Optare’s board. It claims that its products already carry over 60 million passengers a day – more people than the entire Indian rail network – and, the deal brings together two bus-making firms that trace their roots to the Leyland brand, once the largest bus maker in the world.
New bus tyres from Goodyear
Goodyear says it will introduce its UrbanMax range of bus and municipal vehicle tyres in the UK. The company says this range offers high mileage and “superb braking” on wet roads, and in winter weather. They use the latest materials, tread patterns and carcass design to ensure lower fuel use, and up to 40% more mileage than predecessor models. Goodyear says that the all-season capability also minimises the need for separate summer and winter tyres on city buses, fire engines, waste-removal trucks and other municipal vehicles, and they will meet the new EU noise laws. This entire new range is regroovable and retreadable.