Zhongtong LCK6121GHEV
SMRT Zhongtong LCK6121G HEV
Manufacturer	Zhongtong Bus Holding
Bodywork	Zhongtong (Integral)
Years in operation	2011, 2014 – 2019
Operators	Travel GSH SMRT
Technical Data
Length	12 metre
Engine	Dongfeng Cummins ISBe4 225B
Transmission	Eaton UltraShift F0-6406A-ASW
Accessibility	Low Entry & Wheelchair-accessible
Emission Standard	Euro IV (SCR)

The Zhongtong LCK6121GHEV is a low-entry single-decker hybrid city bus built by Zhongtong Bus. The Chinese bus builder primarily supplies vehicles for the domestic market. Its hybrid drive system was developed by Eaton.

SMRT Buses is a past operator of the LCK6121GHEV, with a single unit brought on trial for six months, where it was rejected after its trial period. The same unit was later sold to local private bus operator Travel GSH, where it was deployed on Peak Period Short Service 291P between 2014 and 2016.

Technical Information:

Being a diesel-electric parallel hybrid bus, it combines a conventional internal combustion engine propulsion system with an electric propulsion system. The small 7-litre diesel engine is supplemented by a 10-60Ah Lithium-Ion Battery, the key to its high fuel economy.

The battery supplies additional power to the bus during acceleration directly to the drive train via a set of permanent-magnet synchronous motors. The batteries are gradually recharged through dynamic braking. The added electric propulsion system reduces the load on the diesel engine, resulting in better fuel economy and lower vehicular emissions.

Introduced in 2011, a similar diesel-electric hybrid bus was trialled by SBS Transit the previous year, with two Sunlong SLK6121UF14H buses introduced the previous year (SBS8000Z and SBS8001X).

SMRT Buses Zhongtong LCK6121GHEV Demonstrator (SMB137A):

In 2011, SMRT Buses brought in its first diesel-electric hybrid bus, and its second China-made bus (after SMB135E, a Yutong ZK6126HGC). Registered on 3 January 2011 as SMB137A, it served on a six-month trial period from January 2011 to July 2011.

Basic Technical Specifications
Engine	Dongfeng-Cummins ISBe4 225B, 6693 cc Power rating of 245 hp (180 kW) @ 2200 rpm Torque rating of 1050 Nm @ 1250 rpm
Motor	Eaton Hybrid Electric Power System Electric motor rated at 60 hp (44 kW) / 420 Nm
Emissions control	Euro IV compliant Selective Catalytic Reduction (SCR) technology requiring diesel exhaust fluids such as AdBlue.
Transmission	Eaton UltraShift F0-6406A-ASW gearbox Six-speed automatic
Bodywork	Zhongtong Bus Integral Bodywork Completely-built-up (CBU) in China and shipped to Singapore fully assembled
EDS	Mobitec MobiLED Electronic Display Signage (EDS) Orange LED matrix

Being a diesel-electric hybrid bus, it combines a conventional internal combustion engine propulsion system with an electric propulsion system. The small 7-litre diesel engine is supplemented by a 10-60Ah Lithium-Ion Battery, the key to its high fuel economy. The battery supplies additional power to the bus during acceleration directly to the drive train via a set of permanent-magnet synchronous motors. The batteries are gradually recharged through dynamic braking. The added electric propulsion system reduces the load on the diesel engine, resulting in better fuel economy and lower vehicular emissions.

On 18 Jan 2011, SMRT issued a press release about SMB137A as follows:

“Continuing its focus on customers, SMRT Buses has put on trial two environmentally-friendly buses. It will introduce its first diesel-electric hybrid bus made by Zhong Tong, one of China’s premier bus manufacturers. This new environmental-friendly bus runs on both diesel and electricity – using up to 30% less fuel and emitting up to 30% less greenhouse gases, making travel on public transport even greener. SMRT’s first hybrid bus also emits less noise, making it a more pleasant journey for passengers and road users. The hybrid Zhong Tong bus will be put on a six-month trial starting 19 January 2011 and will ply on Service 106 first, before being put on Service 945 from April 2011.”

A day later, on 19 Jan 2011, SMB137A made its debut on Feeder Service 945, contrary to the April launch as stated in the press release. While on its six-month trial, it was under the care of SMRT’s Kranji Bus Depot, and was a common sight on Service 106, Service 188, Premium 530 and Feeder Service 941. It was also deployed to the high-demand Service 190.

During its trial period, it was evident that the Zhongtong was not capable of handling heavy loads, and was frequently running behind schedule on feeder and trunk routes alike. Acceleration was slow and the bus felt sluggish. After its six-month trial, the bus was deregistered, with no further purchases made. It resided in a private heavy vehicle park near Bukit Batok Driving Centre, until it was acquired by a private operator, Travel GSH Pte Ltd. It retained its SMRT beige & red base livery (but without the SMRT logos) and the front Zhongtong badge, before being re-stickered with its new livery.

Travel GSH Pte Ltd:

Following the successful tender for three PPSS services, Travel GSH Pte Ltd acquired the bus and re-stickered it into a green and white livery which promotes the hybrid properties of the bus. The bus was re-registered as PC2086J.

Between June 2014 and September 2016, the bus was a common sight on Peak Period Short Service 291P, operating during the weekday peak hours between Tampines Bus Interchange and Tampines Street 33, and one of three buses deployed on the route. Shortly before the route’s withdrawal, the green and white livery was removed and re-stickered with a Night Safari advertising wrap.

In 2019, it was converted to an office space and was de-registered on 4 Jun 2019.

Additional Specifications:

SMB137A has a total licensed capacity of 81 passengers, including 34 seating, 47 standing, and one passenger-in-wheelchair. A manually-operated wheelchair ramp at the exit door allows for disabled access.