Dennis Trident 3
Dennis Trident 3 (marketed as 3-axle Dennis Trident), is the first low floor tri-axle double-decker bus chassis built by Dennis in the United Kingdom, with a large number purchased by bus companies in Hong Kong, Singapore, the United States and Canada. Design The Trident 3 chassis was developed from Dennis Lance. It had a longitudinally-mounted rear engine, with a radiator mounted on the right hand side of the engine. An auxiliary axle was mounted behind the second axle to cope with the weight at the rear and reduce the rear overhang. Trident 3 was available in 4 different body lengths: 10.3m (specially designed for New World First Bus), 10.6m, 11.3m and 12m. It could be fitted with Alexander ALX500 or Duple Metsec DM5000 bodywork with either a closed top or an open top. Engine The engines used for these double-decker buses were all manufactured by Cummins. Earlier models use the M11-305E, a 305 hp engine which complies with Euro II standards, or an ISM-330 330 hp engine for the buses delivered to North America. The M11-305E engine was replaced by the Cummins ISMe Euro III-standard engine in 2001. A 330 hp version (the ISMe330) was used initially, but later models in Hong Kong adopted a 335 hp (ISMe335) version. Gearbox For original Euro 2 Cummins M11 Units, the options of gearbox included Voith DIWA 863.3/864.3/864.3E and ZF Ecomat 5HP590. For later Euro 3 Cummins ISMe/ISM Units, the options of gearbox included Voith DIWA 864.3E and ZF Ecomat 2 5HP602C. The prototypes Six prototype Dennis Trident 3 chassis were built in 1996. The first Trident 3 chassis was delivered to Alexander in late 1996 and received a body with the front resembled to R-type design, as the ALX500 front design was not yet ready. It was retained by Dennis as a development vehicle. In 2005, it was converted to open top and sold for promotion of British newspaper The Sun. The prototype was sold to a buyer in Hong Kong in October 2019. The other 5 were all delivered to Hong Kong, two went to Kowloon Motor Bus and three to Citybus. Hong Kong Kowloon Motor Bus and Long Win Bus Prototypes The assembly of the first Trident for Hong Kong was finished in February 1997. It has an Alexander ALX500 bodywork and had Kowloon Motor Bus (KMB) air-conditioned bus livery. However, Dennis reserved this bus for tests initially. The second prototype was finished and delivered to Hong Kong in May 1997, also having an ALX500 body and the KMB air-conditioned bus livery. When it arrived Hong Kong, it was repainted with a golden colour. A red line indicating the floor of bus compartment was added, with people-like figures (designed with computers) situated just above the red line. This decoration work was for the purpose of showing that this bus is a "Super-low-floor" bus, which has better accessibility for passengers. The bus was assigned for several open activities for promotion before getting licensed in September 1997. It entered service two months