SUTRA, abbreviation for Scomi Urban Transit Rail Application, is a
monorail
A monorail (from "mono", meaning "one", and "rail") is a railway in which the track consists of a single rail or a beam.
Colloquially, the term "monorail" is often used to describe any form of elevated rail or people mover. More accurately, ...
electrical multiple unit
An electric multiple unit or EMU is a multiple-unit train consisting of self-propelled carriages using electricity as the motive power. An EMU requires no separate locomotive, as electric traction motors are incorporated within one or a number ...
(EMU) type train system designed by Malaysian rail company
Scomi Rail
Scomi Rail, formerly MTrans and Monorail Malaysia, was a Malaysian rail system manufacturer specializing in monorails. A subsidiary of Scomi Group, the company was one of the world's three leading providers of monorail systems, and one of only f ...
. The design is currently the main product offering of Scomi Rail, which has won several contracts with the design, with the first customer being the
Mumbai Monorail
MMRDA Mumbai Monorail is an monorail system in the city of Mumbai, Maharashtra, India, built as part of a major expansion of public transport in Mumbai, public transport in the city. The project was implemented and is currently operated by the ...
project.
In 2019 Scomi Rail was placed in receivership and it is no longer selling its monorail system.
Background
In late 2006, Scomi Rail decided to develop its own next generation monorail after gaining experience from the manufacture of the
KL Monorail system. Within twelve months after commencing engineering design, on 26 November 2007, the SUTRA was unveiled by the then Malaysian deputy prime minister
Datuk Seri Najib Tun Razak
Dato' Sri Haji Mohammad Najib bin Tun Haji Abdul Razak ( ms, محمد نجيب بن عبد الرزاق, label= Jawi, script=arab, italic=unset, ; born 23 July 1953) is a Malaysian politician who served as the 6th prime minister of Malaysi ...
, who described the launch as "a significant milestone".
The total investment expenditure spent by
Scomi Rail
Scomi Rail, formerly MTrans and Monorail Malaysia, was a Malaysian rail system manufacturer specializing in monorails. A subsidiary of Scomi Group, the company was one of the world's three leading providers of monorail systems, and one of only f ...
for the SUTRA monorail was about RM35mil including for research, development and factory expansion.
Design
The SUTRA complies with 50 international standards comprising safety, quality assurance, vehicle certification, reliability, availability and maintainability.
Compared to the previous design used in the
KL Monorail, the SUTRA has improved features such as a
composite
Composite or compositing may refer to:
Materials
* Composite material, a material that is made from several different substances
** Metal matrix composite, composed of metal and other parts
** Cermet, a composite of ceramic and metallic materials
...
body and interior panel, new
bogie
A bogie ( ) (in some senses called a truck in North American English) is a chassis or framework that carries a wheelset, attached to a vehicle—a modular subassembly of wheels and axles. Bogies take various forms in various modes of transp ...
system and structure, mass transit components
drive train, improved propulsion and control system, and
regenerative and
pneumatic brake system. The SUTRA is also more energy-efficient due to an improved direct-drive propulsion system and lower vehicle weight. The SUTRA also has a smaller turning radius of 50m and can also handle gradients on a slope of up to six degrees. The SUTRA also features couplings for up to eight cars that have a capacity of 1,050 passengers.
General

The SUTRA is a highly customisable design, and is designed to accommodate two to eight cars per set, with capacity ranging from 6,400
pphpd
Passengers per hour per direction (p/h/d), passengers per hour in peak direction (pphpd) or corridor capacity is a measure of the route capacity of a rapid transit or public transport system.
Definition
The corridor capacity in the passenger tr ...
in the four-car
KL Monorail to 36,000 in the 5/6-car
Line 17 (São Paulo Metro)
Line 17 (Gold) ( pt, Linha 17–Ouro) is an under construction monorail project for the São Paulo Metro. The line will have 14 stations, beginning at the São Paulo-Morumbi station and ending at the Jabaquara station, with a branch to Congonha ...
and
Manaus Monorail
Manaus Monorail ( pt, Monotrilho de Manaus) is a straddle monorail planned for construction in the Brazilian city of Manaus. In February 2012, the Infrastructure Secretariat of Amazonas signed a contract with a consortium of CR Almedia, Mendes J ...
.
The
monocoque (load-bearing single-shell frame) body structure of the SUTRA is constructed with
aluminium extrusion
Extrusion is a process used to create objects of a fixed cross-sectional profile by pushing material through a die of the desired cross-section. Its two main advantages over other manufacturing processes are its ability to create very complex ...
materials. The lightweight structure combined with the aluminium apron structure provides enhanced strength and durability of up to 30 years.
The SUTRA's propulsion is provided by an
electric motor with
gear reducers which draws power from the 750 V DC power line. The motor of the SUTRA is fitted with a
variable-voltage-variable-frequency (VVVF) drive which is fine-tuned for smooth acceleration / deceleration. The VVVF has high torque and duty cycle capabilities, rated at a power of 200
kW.
The brake system consists of
electro-pneumatic
The electro-pneumatic action is a control system by the mean of air pressure for pipe organs, whereby air pressure, controlled by an electric current and operated by the keys of an organ console, opens and closes valves within wind chests, allowing ...
systems and
regenerative brakes, providing multiple uses including high integrity
emergency brakes, service brakes, security brakes and parking brakes.
The SUTRA has an automatic
coupling system that can connect up to eight cars together. The coupling system is also capable of towing another SUTRA during emergency connections and is also designed to absorb impact energy in case of accidents.
Interior
The interior of the SUTRA is customisable, and was designed with the consideration of passenger safety and comfort. It was designed with a minimalist concept with the aim of increased interior space and maximised flow of passengers and minimised obstruction in and around doorways.
Hand rails and
stanchions are available to assist safe boarding, seating, standing and alighting assistance, including for persons with disabilities.
Other safety features include an emergency door release knob and emergency passenger intercom as well as emergency ventilation windows.
The flooring of the SUTRA is slip-resistant and made of
fire-retardant material. Each car has a 40 kW roof mounted air conditioning unit. Passenger information systems include
LED
A light-emitting diode (LED) is a semiconductor Electronics, device that Light#Light sources, emits light when Electric current, current flows through it. Electrons in the semiconductor recombine with electron holes, releasing energy i ...
texts and television screens in addition to
audio
Audio most commonly refers to sound, as it is transmitted in signal form. It may also refer to:
Sound
*Audio signal, an electrical representation of sound
*Audio frequency, a frequency in the audio spectrum
*Digital audio, representation of sound ...
announcements.
The cabs are equipped with specially designed mass transit seats and two adjacent flippable seats as well as a disabled wheelchair area, which also functions as a standing area when not utilised. Similar to the previous generation Scomi monorails, there are center seats which also function as
bogie
A bogie ( ) (in some senses called a truck in North American English) is a chassis or framework that carries a wheelset, attached to a vehicle—a modular subassembly of wheels and axles. Bogies take various forms in various modes of transp ...
covers.
Vehicle management

The vehicle management system (VMS) provides supervised control, monitoring and diagnostic systems for train operators.
Train status information is graphically displayed to the operator via the
HMI
HMI may refer to:
Companies and organizations
* Hahn-Meitner-Institut, now Helmholtz-Zentrum Berlin, a German research institute
* Hanson Musical Instruments, a manufacturer of electric guitars
* Hartz Mountain Industries, an American holding com ...
panel. The user-friendly interface display allows the operator to quickly respond and understand all train system status.
The train system status and abnormal conditions are categorised and displayed in real time and prioritised in order of critical system hierarchy. As an option, critical data can be logged for further analysis.
The train is equipped with
automatic train protection
Automatic train protection (ATP) is a type of train protection system which continually checks that the speed of a train is compatible with the permitted speed allowed by signalling, including automatic stop at certain signal aspects. If it is ...
(ATP) system to prevent collisions. The ATP system can be optionally upgraded to an
automatic train operation (ATO) system to automate operations of the monorail.
Users
Operational
*
KL Monorail –
Kuala Lumpur, Malaysia
**Quantity: 12 units of 4-car sets on order. Only 6 units delivered. All 6 were taken out of service in May 2017 due to safety reason.
**Capacity: 6,400
pphpd
Passengers per hour per direction (p/h/d), passengers per hour in peak direction (pphpd) or corridor capacity is a measure of the route capacity of a rapid transit or public transport system.
Definition
The corridor capacity in the passenger tr ...
*
Mumbai Monorail
MMRDA Mumbai Monorail is an monorail system in the city of Mumbai, Maharashtra, India, built as part of a major expansion of public transport in Mumbai, public transport in the city. The project was implemented and is currently operated by the ...
-
Mumbai, India
**Quantity: 16 units of 4-car sets
**Capacity: 10,000
pphpd
Passengers per hour per direction (p/h/d), passengers per hour in peak direction (pphpd) or corridor capacity is a measure of the route capacity of a rapid transit or public transport system.
Definition
The corridor capacity in the passenger tr ...
Contracted
''a contract was signed in 2012 but the project never began construction''
*
Manaus Monorail
Manaus Monorail ( pt, Monotrilho de Manaus) is a straddle monorail planned for construction in the Brazilian city of Manaus. In February 2012, the Infrastructure Secretariat of Amazonas signed a contract with a consortium of CR Almedia, Mendes J ...
–
Manaus
Manaus () is the capital and largest city of the Brazilian state of Amazonas. It is the seventh-largest city in Brazil, with an estimated 2020 population of 2,219,580 distributed over a land area of about . Located at the east center of the s ...
, Brazil
**Quantity: 10 units of 6-car sets
**Capacity: 36,000
pphpd
Passengers per hour per direction (p/h/d), passengers per hour in peak direction (pphpd) or corridor capacity is a measure of the route capacity of a rapid transit or public transport system.
Definition
The corridor capacity in the passenger tr ...
.
On hold.
Cancelled
*
Line 17 (São Paulo Metro)
Line 17 (Gold) ( pt, Linha 17–Ouro) is an under construction monorail project for the São Paulo Metro. The line will have 14 stations, beginning at the São Paulo-Morumbi station and ending at the Jabaquara station, with a branch to Congonha ...
–
São Paulo, Brazil Contract with Scomi terminated for non-performance in 2019, awarding to
BYD instead.
**Quantity: 24 units of 3-car sets upgradeable to 18 units of 5-car sets
**Capacity: 36,000
pphpd
Passengers per hour per direction (p/h/d), passengers per hour in peak direction (pphpd) or corridor capacity is a measure of the route capacity of a rapid transit or public transport system.
Definition
The corridor capacity in the passenger tr ...
*
Line 18 (São Paulo Metro)
Line 18 (Bronze) ( pt, Linha 18–Bronze) was a project of the São Paulo Metro. It would link São Paulo to the southeast portion of the Greater São Paulo, ending in São Bernardo do Campo. The line was expected to be the first São Paulo Metro ...
–
São Paulo, Brazil
**Quantity: Unconfirmed number of 5-car sets.
Line cancelled.
**Capacity: 21,000
pphpd
Passengers per hour per direction (p/h/d), passengers per hour in peak direction (pphpd) or corridor capacity is a measure of the route capacity of a rapid transit or public transport system.
Definition
The corridor capacity in the passenger tr ...
References
{{Rail transport in Malaysia
Mumbai Monorail
750 V DC multiple units
Multiple units of Malaysia
Electric multiple units of India