Bus operations in the Northern Beaches and Warringah areas have always required high-capacity buses to cope with peak hour loads. Up until the early to mid 1980s, double deckers handled this task, being both of the earlier rear-platform and later Atlantean types.
However with the fallout from the Atlantean one-man dispute still lingering, the Urban Transit Authority looked to alternate high capacity buses. In 1981, a Mercedes-Benz O305G articulated or bendy bus, numbered 2550 and bodied by Pressed Metal Corporation, was trialled.
The trial was successful enough for a further 29 Mercedes-Benz O305G with Pressed Metal bodies, to be ordered.
Including 2550, all were bodied to the same style as the rigid Mark III O305 buses entering service at the time. The first of the production batch buses, 2551, entered service in September 1983. The eventual fleet of 30 O305Gs were numbered from 2550 to 2579, and all were delivered by April 1984.
However, it was not until 1985 that reconstruction of the Bilgola Bends on Barrenjoey Rd allowed them to run to Avalon and Palm Beach. It was not until 1986 that the last Atlanteans were withdrawn following their replacement by rigid buses on the 189 to Taylors Point - a tight and twisty run that could not handle a bendy bus.
The Museum's bus, 2556, entered service in December 1983. It was allocated to Brookvale depot. For the first few years of service, the O305Gs were only allocated to special split shifts, running two or three trips in the morning or afternoon peaks only. Conductors were still employed on buses at this stage, and on some morning runs would collect fares on an articulated bus to a main location. The conductor would then alight, and the bus would run express to the terminus as a one-man bus.
By the early 1990s the last of the conductors had been phased out, the special bendy bus shifts discontinued and they entered general service.
2556 worked from Brookvale depot from delivery in 1983 until 2009, apart from a short stint at Mona Vale. In 1996, the original three-speed automatic Mercedes gearbox was replaced by a five-speed automatic ZF gearbox, one of only two O305Gs to be modified in such a way.
In November 2009, the delivery of new Volvo B12BLE articulated buses to Brookvale saw it sent down to Port Botany depot in the south-east area, where it remained until April 2010. It was withdrawn from STA service, and donated to the Museum for preservation.
The bus remained in storage until 2013, when it could be registered as a 30-year-old historic vehicle. In time it is planned to have the bus restored to its original brown, orange and white livery, however for now it represents an as-withdrawn STA bus.
Engine: Turbocharged 6-cylinder Mercedes-Benz OM407hl diesel engine developing 207kw.
Transmission: ZF 5HP500 5-speed automatic gearbox to a hub reduction assembly on the rear axle.
Brakes: Dual circuit air brakes, bus stop brake and a spring applied parking brake.