Volvo B5RLE Hybrid

The Volvo B5RLE Hybrid (5-litre Rear-engined, Low-Entry Hybrid bus) is a low-entry single-deck transit bus built by Volvo Buses for the Asia-Pacific market. Commonly simply referred to as the “B5R“, the chassis is manufactured in Europe, and the bodywork supplied by Volgren of Australia.

As part of a revenue service trial, the sole Volvo B5RLE Hybrid unit in Singapore is maintained by SBS Transit, Singapore’s major public bus operator. First introduced in 2015, the Volvo B5RLE hybrid is the second model of hybrid bus introduced by SBS Transit, following two units of the Sunlong SLK6121 Hybrid which went on trial in 2010.

Other foreign operators of the Volvo B5RLEH include Transperth and Torrens Transit, based in the Australian cities of Perth and Adelaide respectively.

Technical Data:

As its name implies, the Volvo B5RLE is a Hybrid bus, running on both diesel and electricity (more specifically, a parallel hybrid drivetrain), which achieves up to 30% fuel savings and reducing CO2 emissions by the same amount. 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.

Electricity is generated during cruising and regenerative braking, and stored in lithium-ion battery cells. The energy in the batteries is released to assist the engine in powering the vehicle. Hence, the engine is less strained while accelerating or going up hills, reducing fuel consumption.

The bus uses a parallel hybrid system developed by Volvo known as the Integrated Starter Alternator Motor (I-SAM), comprising a permanent magnet motor/generator with a Powertrain Control Unit and a DC/AC Power Electronic Converter (PEC) to convert the electrical energy into mechanical energy and vice versa.

In a parallel hybrid drivetrain, the combustion engine and the electric motor are connected to the transmission independently. During acceleration, both the electric motor and the combustion engine power the transmission This differs from a series hybrid drivetrain, where the bus is propelled exclusively by the electric motor, and the internal combustion engine is connected to an electric generator which converts the energy produced by the internal combustion engine into electric power for the motors.

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Background:

The Volvo B5RLE Hybrid trial in Singapore was initiated by Volvo Buses without Government funding, to test the performance of Volvo diesel hybrid buses in tropical climates like Singapore. One trial unit, SBS8002T, was trialled on various bus serviced during its 2-year stint in Singapore.

The bus was permitted to operate on Singapore’s roads under the Road Traffic Act. In the first trial phase, the bus operated on bus services 506, 185 and 143. The second trial phase saw the bus being operated on bus services 268 & 13.

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SBS Transit Volvo B5RLE Hybrid Demonstrator Unit:

A single Volvo B5RLE Hybrid bus was brought in by Volvo Buses for SBS Transit around 2014; the second model of hybrid-electric bus introduced by the operator. The bus was spotted in Hougang Bus Depot in full white livery in early 2014. Revenue service equipment was installed on 26 June 2014. Registered on 16 February 2015 as SBS8002T, the registration follows the two previously-introduced Sunlong SLK6121 Hybrid buses which went on trial in 2010, then registered as SBS8000Z and SBS8001X.

General Specifications:

• Volvo D5F215 diesel engine
  – Rear-mounted, 4-cylinder turbocharged & intercooled (4764cc)
  – Power rating of 216 hp (161 kW) @ 2200 rpm
  – Torque rating of 800 Nm @ 1200 – 1700 rpm
• 120kW electric motor with Li-Ion batteries for additional power
  – Output of 161 hp (120 kW) / 800 Nm (Maximum), 94 hp (70 kW) / 400 Nm (Continuous)
  – 600V / 4.8 kWh Li-Ion batteries
• Euro-V compliant
  Parallel-hybrid drive system in addition to Selective Catalytic Redution (SCR) Technology.
• Volvo AT2412D I-Shift transmission
  Automated manual gearbox with 12 forward gears and 4 reverse gears; integrated electric motor serves as a retarder.
• Volgren CR228L bodywork
  Bus assembled by Volgren of Australia
• Spheros REVO-E roof-mounted air-conditioning
• Mobitec MobiDOT Electronic Display Signage (EDS)
  Green flip-dot matrix design
• Licensed carrying capacity of 74 passengers: 31 seated and 43 standing
• Thoreb ELSY Intelligent Electrical System
  Integrated Bus Computer that allows setting of destination signs, air-conditioning system, system checks, and automated switching of views from in-bus cameras.

Being a diesel-electric hybrid bus, the Volvo B5RLEH combines a conventional internal combustion engine propulsion system with an electric propulsion system. The small 4.7-litre diesel engine is supplemented by the Integrated Starter Alternator Motor (I-SAM) system, the key to its high fuel economy. The I-SAM system draws from its Lithium-Ion batteries and supplies additional power to the bus during acceleration directly to the drive train via a set of permanent-magnet motors, with a maximum output of 120kW and also powering other systems onboard the bus. The batteries are gradually recharged through regenerative braking. The aforementioned I-SAM electric propulsion system reduces the load on the diesel engine, resulting in better fuel economy and lower vehicular emissions.

Another unique feature of the bus is the Volvo AT2412D I-Shift semi-automatic transmission, where the bus executes manual gear changes automatically, without any input from the driver. The bus accelerates in ‘steps’ very similarly to a manual transmission, but the optimized transmission keeps the acceleration smooth.

While the vehicle is equipped with a wheelchair ramp as per Australian specs, it is prevented from carrying persons-in-wheelchairs (PIWs) during the course of its trial. As mentioned in the exemption order, “Volvo or SBST must ensure that where the DHB (diesel hybrid bus) is used to provide any of the specified bus services, it is used as such only in place of an omnibus which is not constructed or adapted to provide access to wheelchair users.”

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Interior:

The bus sports a grey-themed interior, with blue felt seat covers and yellow grab poles. Similar to newer low-floor single-deck buses, a seat at the rear row is removed to make room for additional components. Double-leaf doors are used for both entrance and exit, and supplied by SMC Transit. Three steps separate the low-floor front section with the elevated rear seating section of the bus.

As the bus will not carry wheelchair passengers for purposes of the trial, the six foldable side-facing seats at the front half of the bus (three on each side) have been secured in place, and the wheelchair backrest had been removed. The only rear facing seats are located at the kerbside, just behind the rear door.

Custom Livery:

SBS8002T was stickered with a custom livery in late Feb 2015, days before its debut on revenue service. The blue and green theme of the advertisement promotes the environmentally-friendly aspects of the bus.

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Trial Period (2015):

SBS Transit was permitted to operate the Volvo B5RLEH for the duration of one year (15 Sep 2014 to 14 Sep 2015) under the Road Traffic (Volvo Diesel Hybrid Bus Trial) (Exemption) Order 2014. The bus was limited to routes 143, 143A, 174, 174e, 185, 334 and 506 which are all based in Soon Lee Depot. It is worth noting that 143A had been withdrawn when the bus was registered.

Service 506: 01 Mar 2015 – 15 April 2015

On the first day of service (01 Mar), the bus broke down in the afternoon and was taken off revenue service due to faulty air conditioning, and returned to service on Tuesday (03 Mar). The bus was deployed on Service 506 for less than a month before being removed from revenue service, likely due to air-conditioning problems.

Service 185: 16 April 2015 – 13 August 2015

After not being seen on the roads for weeks, SBS8002T returned to operated on Service 185 on 16 April 2015. However, the bus was withdrawn from service later in the day due to faulty air-conditioning. On 24 April 2015, SBS8002T ran again on Service 185 in the afternoon. 2 representatives from Volvo Buses were monitoring the data from the bus while it ran on revenue service. The bus was later swapped out with a Scania K230UB after their data collection run. On the afternoon of 28 April 2015, SBS8002T was declared broken down again, as a heavy downpour affected the door sensors and prevented them from closing. The bus was only seen occasionally during this period.

Service 143: 14 August 2015 – 10 September 2015

The bus made its first appearance on Service 143 on 14 Aug 2015, and was regularly deployed on a split shift duty. The last day of service was 10 September 2015 (Thursday), and its evening trip was met with many bus enthusiasts bidding farewell to the bus’ one-year stint in Singapore.

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Trial Period (2016):

After the trial in 2015, the bus went on a hiatus, with its fate unknown. On 11 Feb 2016, the Road Traffic (Volvo Diesel Hybrid Bus Trial) (Exemption) Order 2016 was passed, stating that the Volvo B5RLEH Bus will be allowed another six-month trial, from 12 Feb 2016 to 28 Aug 2016. The bus is currently based in the East District depots and bus parks (Ang Mo Kio, Braddell, Bedok North and Changi). The routes permitted for the trial of the Volvo hybrid bus are 13/A, 21/A, 26, 29/A, 38, 45/A, 54, 63, 70/A/B/M, 73, 124, 130, 131/A, 135/A, 139, 145/A, 155/A, 162/M , 222/A, 265, 268/A, 269/A, 293 and 410G/W.

Service 268: 20 February 2016 – June 2016

On Saturday, 20 Feb 2016, SBS8002T made its second trial period debut on Service 268, plying between Ang Mo Kio Depot and Ang Mo Kio Industrial Park 2.

On weekdays, the bus was usually deployed on a split-shift duty, running Shortworking Trip 268A in the AM Peak hours, and full-trip Service 268 during PM Peak hours. During off-peak hours, the bus will be parked at Ang Mo Kio Depot.

On weekends, the bus will be deployed on a full-day duty.

Service 13: 04 July 2016 – 28 Aug 2016

On Monday, 04 July 2016, SBS8002T made its debut on Service 13, plying between Yio Chu Kang Bus Interchange and Upper East Coast Terminal. The bus was spotted training on Service 13’s route the day before on 03 July 2016.

End Of Trial

The bus was de-registered in October 2016 after the end of its trial period.

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Accident

On 15 June 2015, SBS8002T was involved in an accident along Commonwealth Ave West, near Clementi MRT Station. The bus was rear-ended by a tipper truck which caused dents / scratches on the right end of the bus. The bus was subsequently towed back to Soon Lee Bus Park to await repairs.

As of 24 June 2015, SBS8002T returned to service 185 with re-stickered livery on the right side of the rear, starting from the right EDS of the back signage. It can be distinctly seen from the slight difference of colour as the original livery has faded slightly over time.

Trivia:

The bus was on display at the 2013 Australian Bus and Coach Show in Sydney.

This bus has been nicknamed the “tissue box” among bus enthusiast circles, for the blue and green livery combined with the white air-con pod resembles exactly that.

Additional Details:

Chassis No.: YV3T8R921DA161750
Engine No.: D5F11392998
Motor No.: 01302516
Engine Capacity: 4764 cc
Power Rating: 120.0 kW
Max Laden Weight: 18600 kg
Unladen Weight: 10800 kg

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