The Volvo B5LH (also known as the Volvo BRLH or B5L Hybrid) is a low-floor, twin-axle, diesel-hybrid city bus chassis built by Volvo Buses for both single-deck and double-deck buses. The bus is commonly fitted in Europe as a double-deck bus, with bodywork options from Wrightbus, ADL and MCV. The standard 10.5-metre Volvo B5LH low-floor chassis is available in both LHD and RHD models. Currently, an 18.0-metre articulated variant is also offered.
50 units of the Volvo B5LH 12-metre single-deck bus were procured by the Land Transport Authority in 2017 as part of efforts to build a more environmentally friendly public bus fleet. These buses are bodied with the MCV Evora bodywork (stylized as eVoRa) and have entered service from December 2018. Read more about the procurement process here. In media releases from LTA and Volvo, this bus is often referred to simply as the Diesel Hybrid Bus.
One chassis unit is housed at the Bus Technical Specialist Certification Centre (BTSCC), located at Ulu Pandan Bus Depot and used for technician training. It was exhibited at the Ulu Pandan Bus Depot Carnival in October 2018, where photos used in this article were taken.
Background
Pre-production units of the Volvo B5LH were manufactured in 2008, with serial production commencing in 2010. Like the Volvo 7900 Hybrid, was initially offered with a Euro V/EEV diesel or CNG engine in both rigid and articulated bus variants. The Euro VI engine range was offered starting from 2013.
As its name implies, the Volvo B5LH runs on both diesel and electricity (more specifically, a parallel hybrid drivetrain), which achieves up to 39% fuel savings and reducing NOx/PM emissions by almost to 50%. By using electricity to power the bus during periods of high energy demand, less strain is put on the combustion engine, hence lowering fuel consumption and emissions. A similar Volvo B5RLE Hybrid was trialled in Singapore in 2015 and 2016.
In Singapore, 50 units of the Volvo B5LH bodied with the MCV Evora bodywork were procured by the Land Transport Authority in 2017.
Overview
This article will provide a very basic introduction to the main subsystems of a bus, with accompanying photos of its chassis, and (hopefully) some appreciation for the complex mechanisms behind a modern hybrid bus.
The bus chassis is the base structure for which the Volvo B5LH bus is built. Volvo offers the Volvo B5LH product as a chassis while integrating the same hybrid driveline on its other products such as the Volvo B5RLE, and the Volvo 7900 Hybrid and Volvo 8400 integral city buses. The chassis exhibited at the carnival was a transport chassis, where components are arranged for shipment rather than their actual position on the completed bus. Apart from being shorter than a regular 12m bus (prior to chassis extension), several roof-mounted components are placed on the floor of the chassis. Additional metal bars on the chassis are added to offer rigidity during transportation.
The Volvo B5LH is also designed with its drivetrain components flushed to the left of the chassis to accommodate a full-low-floor design and a third door at the rear of the bus (for left-hand-drive markets).
