Volvo B10BLE (Diesel)
Introduced in 1998 with a stepless entrance and exit, SBS 1688K was back then, SBS Ltd's first ever Low Entry bus, and one of the first few to feature a Electronic Display Sign (EDS) at the time of introduction. It was configured to only have single seating at the front and featured a wide standing area at the front half of the bus. It had 2 stanchion poles in the middle that provide commuters extra support when standing. Apart from giving commuters more support, the 2 stanchion poles also splits the standing area. The configuration of the interior shared similarities with the Volvo Olympian Batch 2 & 3, from the seat covers to aircon duct to the yellow stanchion poles and finally, the interior lighting. Built with the bodywork make of CR221L by Volgren Australia (A new player of bus and coach building in Singapore at that point of time), it features a 2 piece windscreen that could be more easily replaced, and also the Pantograph wiper system that was once common on the Volvo B10M Mark II, Scania N113CRB, and Mercedes-Benz O405 under SBS Ltd. Since the retirement of the said models, the Pantograph wiper system became a rare sight on the public buses in Singapore, with SBS 2888T (Scania L94UB) being the last to feature it. Officially registered in 1998 with a Euro 2 engine, SBS 1688K is the first to feature an even higher emission rating at Euro 2, with a more stringent emission controls, whilst other buses such as the Volvo B10M Mark IV (DM3500) rated at Euro 1 just started to enter revenue service. The trial of the low-entry buses like such may be an attempt by SBS Ltd to evaluate the feasibility and benefits for the Singapore's market. Eventually, more low-entry buses were introduced in 2003, the Volvo Super Olympian. Finally, the introduction of Wheelchair Accessible Buses (WAB) in 2006, where the Volvo B9TL (CDGE) buses were launched. Since then, new buses introduced were either low-entry or full low floor. After a few years of trial of SBS1688K, 2 units of the Compressed Natural Gas (CNG) version were acquired in 2002, presumably to trial on the use of CNG. Thereafter, another 10 units of the CNG version were brought into revenue service in 2005. There was a major absence of single deck low-entry buses until 2007, where the Scania K230UB buses stared to roll in, replacing the retiring fleet - the Volvo B10M Mark II, Scania N113CRB, and the Mercedes-Benz O.405.