Volvo B9TL (CDGE)

 Volvo B9TL (CDGE)
Manufacturer Volvo Buses
Bodywork ComfortDelGro Engineering
Years in operation 2006–Present
Operators SBS Transit
Technical Data
Length 12 metre
Engine Volvo D9A300 EM-EC01
Transmission ZF Ecomat 6HP 602
Voith DIWA 864.3
ZF EcoLife 6AP 1410B
Accessibility Low Entry
Emission Standard Euro III

Main Article: Volvo B9TL

The Volvo B9TL is a rear-engined low-floor double-decker transit bus built by Volvo Buses since 2002. It is the successor to the older Volvo B10TL “Super Olympian” and the Volvo B7TL. The bus is popular in the United Kingdom, Hong Kong and Singapore, and is currently the single most common model of city bus in Singapore.

In 2006, the first 200 units of the Volvo B9TL were brought in by SBS Transit. These units were Euro III-compliant and bodied locally by ComfortDelgro Engineering (the engineering arm of SBS Transit’s parent company, ComfortDelgro). The bodywork was based off the Volvo B10TL (PSV/CDGE) demonstrator which was designed in cooperation with PSV International.

These 200 units would eventually pave the way for the introduction of Euro V-compliant Volvo B9TL buses, bodied with the Wright Eclipse Gemini II bodywork instead.

Design & Technical aspects:

The Volvo B9TL was built to succeed the 2-axle Volvo B7TL and the 3-axle Volvo B10TL “Super Olympian” chassis, and was designed based on the existing Volvo B7TL. A key difference from its B7TL and B10TL predecessors is its new 9.3-liter engine originally designed by Renault Trucks. The larger engine delivers more horsepower, an advantage over the Volvo B10TL which was notorious for its poor performance on steep ascents. Another major design change over the B10TL was the relocation of the water tank from the front of the bus (near the right front wheel) to the rear, next to engine components.

The B9TL was initially offered only in a 12-meter 3-axle format. The 2-axle variant was introduced in 2006 to fully replace the B7TL, with various chassis lengths available (10.3m, 10.4m and 10.6m). The driveline comprises a Euro III-compliant Volvo D9A engine (rated at 300 or 340 horsepower), with Voith of ZF transmission options. The Euro V-compliant Volvo D9B engine would later be offered to replace the D9A engine.

For the bodywork, Manufacturing Commercial Vehicles (MCV) of Egypt would later continue production of the bodywork design between 2011 and 2014, marketed as the MCV DD103 and paired with a Volvo B9TL 2-axle chassis. It saw little bulk orders during its short production run and was later succeeded by the MCV Evoseti.

Volvo B9TL (Euro III) – PSV/CDGE bodywork (200 units)

In late 2004, SBS Transit placed orders for 150 Euro III Volvo B9TL chassis at a cost of S$71 million on 28 December 2004, with an option for 50 more units. They were bodied by ComfortDelGro Engineering (CDGE), the engineering branch of SBS Transit’s parent company ComfortDelGro. A trial bodywork had previously been tested on a Volvo B10TL (SBS9889U), developed by SBS in cooperation with PSV International. The new bodywork was ready to be refitted for use on the Volvo B9TL.

Volvo B9TL CDGE at a launch ceremony
A Volvo B9TL CDGE at a launch ceremony

On 15 February 2006, a prototype bus was unveiled, a Volvo B9TL with a zero-step entrance, a manual wheelchair ramp and other wheelchair-friendly features. As Singapore’s first Wheelchair-Accessible Bus (WAB), they were going to pave the way for more WABs and a more disabled-friendly transport system. The launch date was delayed from April to June to prepare bus stops for wheelchair boarding and alighting activities. Finally, on 27 June 2006, SBS Transit Service 21 became the first wheelchair-accessible bus service with 10 Volvo B9TL CDGEs in its fleet.

Later in 2006, SBS Transit exercised its options for an additional 50 more buses at a cost of S$29 million, soon after putting its first B9TLs into operation, bringing the total fleet size to 200. These B9TLs come with the same Euro III-compliant Volvo D9A300 engine, but a four-speed Voith gearbox instead of the six-speed ZF. All units were registered just days before the government-set deadline for Euro-IV compliant diesel engines. Volvo B9TL CDGE units were registered between 17 May 2006 and 28 Sep 2006 with the registration numbers SBS7300P to SBS7499A.

Basic Technical Specifications
Engine Volvo D9A300 EM-EC01 engine, 9364 cc, Euro III-compliant
Power/Torque rating of 300 hp (220 kW) @ 1900 rpm / 1400 Nm @ 1100 – 1400 rpm
Transmission ZF Ecomat 6HP 602 gearbox (149 units) – Six-speed automatic
Voith DIWA 864.3 gearbox (50 units) – Four-speed automatic
ZF EcoLife 6AP 1410B gearbox (1 unit) – Six-speed automatic
Bodywork PSV International / ComfortDelGro Engineering Bodywork
Prototype bodywork designed by SBS and PSV International
Built by ComfortDelGro Engineering
EDS LECIP Electronic Display Signage (EDS)
Orange LED matrix mounted on front, side and rear
Formerly using plastic destination signs on front, side and rear
Doors SMC Transit doors
Double-leaf entrance, double swinging plug exit
Capacity Licensed capacity of 124 passengers:
53 upper deck seating, 27 lower deck seating and 44 standing
Service 198 - SBS Transit Volvo B9TL CDGE (SBS7323Z)
Service 198 – SBS Transit Volvo B9TL CDGE (SBS7323Z)

The design of the Volvo B9TL (CDGE) buses were adapted from the Volvo B10TL (PSV/CDGE) demonstrator (SBS9889U), which was a prototype bodywork designed by SBS and PSV International, a UK-based company which designs passenger vehicles (including buses) and assembles them in their country of operation, mainly using components sourced regionally.

Similarly, the Volvo B9TL (CDGE) buses were assembled in Singapore by ComfortDelgro Engineering (the engineering branch of Comfort DelGro, SBS Transit’s parent company), with expertise from building SBS9889U. Unlike most SBS Transit (or CDGE)-assembled buses which have their bodywork kits shipped in completely knocked down (CKD) form, CDGE bodied these buses themselves from the chassis up.

The Government had subsidised the cost of fitting the bus with wheelchair-friendly features, such as the manually operated wheelchair ramps. Each bus has one wheelchair bay. The bus was also equipped with safety features such as throttle interlocking, which prevents the bus from moving off when doors are opened. Doors will not open above 5kmh nor close if the wheelchair ramp is still deployed. Additional blinkers on the offside of the bus make the bus more visible to oncoming traffic as it exits a bus bay.

Operational History:
Volvo B9TL CDGE Buses before the installation of EDS units
Volvo B9TL CDGE Buses before the installation of EDS units

Volvo B9TL (CDGE) buses previously used plastic destination signs (‘destos’) on the front, side and rear. In 2011, SBS Transit replaced these with Electronic Display Signs (EDS) supplied by LECIP. SBS7392Z was the first bus to receive it, and all other CDGE B9TLs followed suit. The upgrade consists of three sets of electronic displays, for the front, side and rear of the bus. The new LECIP EDS units had route numbers that were considerably smaller and difficult to see clearly from a distance, but eventually accepted by commuters.

On 7 March 2010, SBS7440T from service 25 was burnt beyond repair in a fire at Ang Mo Kio Bus Depot. It was de-registered several months later, making it the first Volvo B9TL in Singapore to be de-registered.

On 23 April 2018, SBS7428E on Service 72 was involved in a fatal accident outside Yio Chu Kang Bus Interchange, where a lorry mounted the pedestrial sidewalk and hit the bus before coming to a stop, resulting in 3 pedestrian fatalities. The bus was de-registered for a period in 2019, before being reinstated in December 2019.

Transmission Specifications:

SBS7321D had its ZF 6HP602 gearbox replaced with a ZF EcoLife 6AP 1410B gearbox for reasons unknown. The same make of gearbox is fitted to ZF Volvo B9TL Wrights .

Volvo B9TL CDGE transmission
ZF Ecomat 6HP 602 SBS7300P – SBS7341X, SBS7347E – SBS7402D, SBS7448Y – SBS7499A, excluding SBS7321D
Voith DIWA 864.3 SBS7342T – SBS7346H, SBS7403B – SBS7447A
ZF EcoLife 6AP 1410B SBS7321D
Lush Green Livery:

The first Volvo B9TL CDGE, SBS7368U, to be repainted to Lush Green returned to service on 6 October 2018. Repainting of the remaining 198 buses was completed in late September 2019, while SBS7428E was subsequently re-registered and returning to service repainted in lush green livery in December 2019.

While initial units were refurbished with yellow seat covers, subsequent buses had their original yellow seat covers replaced with red seat covers commonly found on other SBS Transit bus models.


Lower Deck

The lower deck of the bus features 27 permanent seats. Being a low-entry bus, the bus offers step-free access only between entry and exit doors, with a raised aisle section leading to the rear seating area. A staircase behind the driver’s cab connects the lower and upper decks.

Like most double-deck buses in Singapore, the Volvo B9TL (CDGE) buses are configured with two doors: an entrance door at the front, and an exit door in the middle. The entrance doors are conventional inward-swinging leaf doors, while the exit doors are outward-swinging swing plug doors. They are supplied by SMC Transit, and are pneumatically operated.

Opposite the staircase, there are four side-facing priority seats, reserved for elderly and handicapped passengers, and passengers travelling with young children. They are indicated in green seat covers.

A wheelchair bay is located behind the staircase and opposite the exit door, which accommodates one passenger-in-wheelchair and doubles up as standing space when not in use. Wheelchair accessibility is offered via a manual ramp installed at the exit door. The Government had subsidised the cost of fitting the bus with wheelchair-friendly features, such as the manually operated wheelchair ramps; however, some buses have had their ramps replaced with a more updated design.

Grab poles and hand grips are located on both sides of the aisle. All seats also have hand grips to provide commuters with additional support.

Bus stopping bell-pushes are located around the bus cabin, either mounted to stanchion poles or on the pillars in-between windows. Emergency hammers are also located on these pillars.

The seating layout at the rear is unique to the Volvo B9TL (CDGE), with aisle-facing seats from the exit door all the way until the last row, which is comprised of 5 front-facing seats. This layout was likely chosen to avoid interfering with the wheel wells of the rear axles, Most other models of double-deck buses had front-facing seats behind the rear exit door.

Upper Deck

The upper deck of the bus is laid out in a conventional four-abreast seating, with a central aisle running the length of the bus.

There are 55 seats on the upper deck. A unique feature on the Volvo B9TL (CDGE) is the side-facing seats at the rear, which maximizes seating capacity since there was no room to install two rows of front-facing seats.

Grab poles run the length of the aisle for commuters moving around the bus. All seats also have hand grips to provide commuters with additional support. Bus stopping bell-pushes are located around the bus cabin, mounted to stanchion poles. Emergency hammers are also located on pillars in-between windows.


The staircase allows for passenger movement between the lower and upper decks of the bus. A seat counter (LCD number display) on the lower deck displays the number of available seats on the upper deck.

Driver’s Compartment

The farebox, New Onboard Bus Equipment (NOBE) fare collection system and Trapeze Common Fleet Management System (CFMS) display unit are located on the left of the instrument cluster. Door controls, light switches and the handbrake lever (out of frame) are located on the right of the driver.


Bus Interiors:
Bus Exteriors (SBS Transit Livery)

External Links & References:

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5 thoughts on “Volvo B9TL (CDGE)

  • 3 December 2019 at 2:37 PM

    Why they scrap 7428E ah? The damange quite minor leh. Or is it too old and not worth repairing?

  • 28 July 2019 at 7:19 PM

    SBS7428E has become the 2nd Volvo B9TL to be scrapped after the Yio Chu Kang Bus Interchange accident.


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