The arrival of new ADL Enviro500 tri-axle double-deck buses to the Hong Kong franchised fleets during 2020 has taken the Cummins L Series engine population up to an in-service record high of 4,500 buses in the territory, the engine manufacturer reports. Built at Cummins’ Darlington facility, it says the 8.9-litre engine has proven to be a robust performer in Hong Kong, operating for up to 20 hours daily on both city and rural routes, together with high-speed airport express services accumulating up to 200,000 km per year.
The latest Hong Kong specification Enviro500 tri-axle double-deck buses feature the Euro VI L9 engine. Rated at 340hp (254 kW) and with 1,500Nm peak torque at 1,200rpm, the L9 gives smooth and quiet operation when fully loaded with over 140 passengers. The high-power density of the L9 is also able to support the power take-off for the powerful air-conditioning systems required in Hong Kong. A Cummins variable geometry turbocharger (VGT) ensures rapid engine response during acceleration.
Hong Kong is home to the largest number of tri-axle double-deck buses in the world, with over 600 routes and over 4.2 million passenger journeys every day. Cummins says it now powers almost 70% of the double-deckers operated by the franchised bus fleets. The Cummins 8.9-litre engine can also be found powering Ankai sightseeing buses operating around the territory.
“Hong Kong presents an arduous bus duty-cycle with very high passenger loadings, a humid climate and steep gradients to climb, but Cummins’ L Series engine has proven to be more than equal to the task and we are delighted to reach a landmark population of 4,500 double-deckers during 2020 in partnership with ADL,” said Ashley Watton, Cummins Director, Bus Business Europe.
“The L9 shares many heavy-duty design attributes such as the XPI fuel system with larger displacement Cummins engines, delivering premium performance but with the lower operating costs and fuel-efficiency of a compact, midrange engine,” he added.
Both ADL and Cummins have a support team in Hong Kong, embedded at fleet depots and working together with the operators to maximize uptime. Cummins also provides technical support and delivers service training.
The L9 engine is supplied with a selective catalytic reduction (SCR) and diesel particular filter (DPF) exhaust aftertreatment system to meet the Euro VI emission standards required for new buses entering service in Hong Kong which is specifically designed for the 8.9-litre platform by Cummins and manufactured alongside the engine in Darlington.