The first articulated bus in Singapore, introduced in 16 March 1996, was flown in through an oversized cargo plane. Trans Island Bus Services (TIBS) dubbed it as the "Bendy Bus" and affixed an identity sticker to it, a term still used today by Singapore bus enthusiasts to refer to any articulated bus in Singapore. A Mercedes-Benz O405G, it was registered as TIB838H and was used to test the viability of bendy bus operations.

TIBS was subsequently satisfied with the performance, and followed up with a further purchase of 56 units. All of them were bodied by Hispano Carrocera, bearing a design that is similar to the existing O405 fleet that was brought in earlier. They powered by by the turbocharged and intercooled Mercedes Benz OM447hLA engine (11,967cc) that is Euro I compliant, and fitted with 4-speed ZF 4HP 590 automatic. Underfloor air-conditioning was supplied by Konvekta, and flip-dot EDS was from Hanover Displays. With a rear-mounted engine, this makes all O405Gs and hence all TIBS bendy buses to be of the pusher configuration.

During that same period in 1996, the other bus operator Singapore Bus Services also began a trial on the possibility of bendy bus operations with a Volvo B10MA demonstrator (puller configuration) and subsequently, a Volgren-bodied O405G. The trial was deemed unsuccessful and no further articulated bus purchases were made. Both of these units were eventually sold to New Zealand.

All SMRT Buses O405G Mk I units were withdrawn from service by November 2015.