Citybus Trolleybus Shows Remarkable Traits

Over Diesels In Trials
Company Called It "Pollution Solution"


Citybus Engineering Consultant, John Blay, heads the trolleybus project team. Said John Blay, "We completed the overhead track in early 2001; and the trolleybus conversion in April 2001, and have continued to test and improve it since then."

According to John Blay, the trolleybus has so far shown to be better than diesel buses in many areas. "The environmental aspect is the leading advantage. In our trials, the trolleybus does not need engine oil and filter changes, avoiding a lot of waste. It also produces no exhaust gas, even when stationary with the air-conditioning on, and is quieter than buses," said John Blay.

"The trolleybus also shows superior performance. Even when fully loaded, the trolleybus accelerated more quickly, and was better at hill climbing than an equivalent diesel bus," John Blay said.

To enhance the power efficiency of the trolleybus network, Citybus installed a flywheel energy storage system, which preserves the electrical power produced when the trolleybus is braking, and then releases that power for the trolleybus to accelerate or climb a hill, reducing the electricity needed by about 15 percent.

By contrast, diesel buses consume fuel, even when stationary. "We downloaded computer data recorded on a Route 10 bus, running between Kennedy Town and North Point. The data showed that during any operational day, the bus is stationery for about 43 percent of the time. Though the bus is stationary, the engine is still running, burning fuel and producing exhaust pollution. In these circumstances, a trolleybus is more environmentally-friendly," said John Blay.

John Blay also demonstrated how the trolleybus can easily overtake vehicles blocking its way.

The Citybus trolleybus is fitted with air-operated boom bases, which enable the trolleybus driver to rewire at designated points with rewiring troughs. "We envisage trolleybuses will leave the service depots and travel to the trolleybus network on the auxiliary power unit (diesel), and join the network at these rewiring troughs," John Blay said.

In March 1999, Citybus announced that it would embark on a HK$5 million trial involving the conversion of a diesel bus into a trolleybus; and building an overhead wire test track in Wong Chuk Hang. The company wanted to offer an alternative, environmentally-friendly mode of public transport. Citybus decided on the conversion as local demand for bus services is high and requires high capacity air-conditioned double-deck buses, which are currently unavailable on the market.

All data gathered from this trial will be submitted to the Transport Department for consideration.

"We firmly believe that the trolleybus is workable for Hong Kong - and would improve air quality in areas worst hit by pollution. The trolleybus is one of the best solutions for reducing roadside pollution caused by public transport," John Blay concluded.