Powering SMRT Trains on the NSEWL

In October 2015, SMRT released the inaugural edition of Your Journey Matters, outlining SMRT’s rail transformation efforts. Almost a year later, we have published Your Journey Matters – Edition 2, which continues the story of SMRT’s ongoing efforts to improve and renew the North-South and East-West Lines (NSEWL) – Singapore’s oldest, longest and most heavily used MRT lines.

The multi-year, multi-project efforts described in Your Journey Matters underline SMRT’s commitment to serve you better. In this new edition, we also bring you updates on the ongoing station upgrades to escalators and platform screen doors, as well as a look into how the air-conditioning is maintained on our trains.

A tremendous amount of work is being put into renewing and upgrading the North-South and East-West Lines (NSEWL), Singapore’s oldest, longest and most heavily utilised MRT lines. The work takes place every day even as the rail network continues to serve passengers for around 20 hours a day and as the system copes with increased ridership.

The transformation of the NSEWL is a complex set of engineering projects. It represents the first major upgrade for the lines since they started operations in 1987. Indeed, the renewal of the NSEWL is said to be the biggest modernisation project on a “live” MRT system anywhere in the world.

This modernisation effort will lead to an updated and renewed railway system that will allow SMRT to run more trains, carry more passengers and serve our passengers better with faster connections across the MRT network. The multi-year, multi-project effort takes place seven days a week, all-year round. Much of the work takes place away from the public eye in train depots, deep underground in train tunnels or during the early hours of the morning when trains have stopped running. Progress is made every day to modernise the NSEWL to serve you better.

With just three hours every night for engineering staff to access the track when trains are not running, it is vital for SMRT to prioritise and allocate the engineering hours and resources properly across different projects. Since 5 June 2016, the implementation of later train service start times on Sundays for 13 stations along the East West Line have given the engineering team much needed additional time to work each night. These extra hours are maximised for urgent maintenance and repair tasks as well as upgrade and renewal projects.

Powering the North-South and East-West Lines

With more trains due to be added to the NSL and EWL, existing power cables have to be replaced with larger capacity cables to accommodate the increase in power demand. SMRT is working with LTA to address the rail network’s future power needs.

A number of measures are being implemented to minimise inconvenience to MRT passengers due to power-related faults. These measures tie in with recommendations made by the Independent Advisory Panel, approved by LTA, on rectification measures to improve the rail power supply system.

These measures include renewing power components that are nearing the end-of-life stage on the 30-year old network with completely new components, increasing the power capacity of the network and thirdly, improving the design of the power network.

In order to improve the design of the power network, Voltage Limiting Devices will replace the existing 64P Earth Fault Relay. Works will be done on the 750V DC Switchgear & DC Cables, Direct Current Group (Rectifiers and Inverter) and High Voltage Group (AC Switchgear & HV cables) in order to renew, upgrade and increase the power capacity.

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This is part of a series on SMRT’s rail improvement efforts. Read more:
SMRT- Track Improvements
SMRT- Airconditioning Improvements
SMRT- Platform Screen Door Maintenance
SMRT- Escalator Maintenance

SMRT Third Rail Maintenance to Prevent Disruptions

The third rail supplies electrical power to the trains operating on the rail line. It is elevated and runs parallel to the rest of the track. A part of the train known as the Current Collection Device (CCD) is in constant contact with the third rail through a component called the CCD shoe. If you imagine the third rail to be similar to the wall socket at home, the CCD is the plug. However, in the context of a train, the “plug” is sliding along a very long “socket”. As such, the alignment of the elevated third rail has to be very precise in order to power the trains at all times.

SMRT Conditioning Monitoring Device_LVDT

The Linear Variable Displacement Transducer (LVDT) helps monitor the alignment of the third rail. The LVDT measures the movement of the CCD shoe and through this data, the system can chart the precise height of every inch of the third rail.

Engineers compare the latest graphs with earlier ones to identify locations where the height of the third rail was recorded as too low, or where the height has changed too much from the last measurement. With this info, the Permanent Way maintenance team can quickly zoom in, inspect and rectify any potential Third Rail faults relating to misalignment.

SMRT Conditioning Monitoring Device_LVDT Graph

With the LVDT technology, the frequency of third rail inspection is increased and real time detection is possible, even during service hours. The degradation trend of the third rail can also be tracked.

The LVDT is the first of a few other condition monitoring devices we will be sharing on this blog. Check back again soon to find out more about the technologies we use to make maintenance of the track as efficient as possible.

Paving the Way for Better Journeys (Jun 2016)

“Paving the Way for Better Journeys” is part of continuing efforts by SMRT to inform, update and educate commuters of the several rail renewal projects.

SMRT Better Journeys Transforming the NSEWLSuch work on SMRT’s North-South and East-West Lines (NSEWL) involve multi-year, multi-programme efforts that include changing old wooden sleepers with concrete ones, replacing signalling systems and renewing the Third Rail, as well as introducing new trains to enhance the service and reliability of the NSEWL to bring Better Journeys to all our commuters.

The key benefits from each of these efforts to commuters include Smoother Rides, Shorter Waiting Times, a More Reliable Network and More Trains (which mean higher frequency).

SMRT Trains’ Managing Director, Mr Lee Ling Wee said, “In total, there are about 200km of track on NSEWL to be renewed and upgraded. Over the past two years, we have been able to carry out these renewal and upgrade work ahead of schedule, even as we continue to keep the network operational every day. We know that the work has caused inconvenience to both commuters and residents who live near MRT track. As such, I would like to express my deepest appreciation to you for your kind understanding, patience and support.”

SMRT Better Journeys Smoother RidesSMRT Better Journeys More Reliable Network

 

SMRT Better Journeys Shorter Waiting TimesSMRT Better Journeys More Trains

Keeping our cool

Air conditioning is a crucial component in keeping commuters cool on the train. Nothing irks us more than hoping to escape the humid Singapore weather by taking the train, only to find it stuffy and warm.

On all North-South and East-West Line trains, there are two air conditioning units per train car. With six cars making up a train, that’s 12 air conditioning units working keep the temperature within the train cool. There are 141 trains for the NSEWL, that’s 1,692 air con units! Excluding those undergoing maintenance on the workshop floor.

So how does SMRT maintain the air conditioning systems on the trains to help you keep cool and carry on?

keepcool

Here are some top reasons for aircon failure according to a recent analysis on data collected from December 2015 to February 2016.

Blown Fuses in the aircon motor

SMRT Technical Officer Hairul Bin Seradeen inpects the aircon unit for defects

SMRT Technical Officer Hairul Bin Seradeen inpects the aircon unit for defects

 

One of the most common reasons for failure was the aircon system fuse. A blown fuse indicates excessive current which could be a result of arcing caused by the carbon dust build up inside the motor.

The source of the carbon dust is the carbon brush, a component in the aircon unit that is in contact with the aircon motor. Through normal operations, the carbon brush is wears down and carbon dust settles on the motor.

A more effective cleaning method to remove excessive carbon dust build-up has been implemented and new carbon brushes are being trialed to reduce the carbon build-up in the long run.

Defective Microcards

Microcards are like the brains of the aircon unit. When there is a defective microcard, the aircon no longer functions the way it is supposed to. In some situations, the unit fails to activate when temperatures get too high.

While replacing the defective microcards with new ones from the manufacturer is one solution, SMRT has been working on a more sustainable solution. The Integrate Electronics Workshop team at SMRT have studied the microcard and have been refurbishing defective microcards.

Leaky tubing

Freon topping up machine

The trains’ aircon units use a gas known as Freon as a refrigerant which cools the air. The Freon gas cycles within the unit in a closed system of coils. If the Freon leaks from these coils, cooling efficiency is reduced. We are stepping up efforts to plug leaks in these tubes though a process known as “brazing”.

The Freon also needs to be topped up when leaks are discovered. The use of a recovery machine ensures that the precise composition of refrigerant is used to ensure cooling efficiency.

 

 

 

Keeping an eye on things

The later models of trains on the NSEWL (KNS and KSF) are all equipped with the Trains Information Management System, or TIMS. TIMS is an entire system of sensors that measure various properties of the train during operations. The internal temperature of each car is one such property.

SMRT on board monitoring

During service, train captains can check TIMS for any aircon faults. When faults are detected, a “field team” is activated. The team will then verify the fault and where possible, rectify the issue immediately. Further inspections to the reported aircon system will also be carried out when the train returns to the depot.

SMRT-NTU Smart Urban Rail Corporate Laboratory Launch

SMRT NTU Corp Lab

From a commuter’s perspective, words like condition monitoring and prediction-analytical techniques may not matter much to their commuting experience.

What weighs heavily in their minds are questions like how crowded will the next train be, how long do I have to wait for my next train, and will I be able to reach my destination safely and on time?

At SMRT, we continue to have an unwavering commitment towards our commuters and have undivided focus towards solving present issues. We are fully aware that our rail system is an integral part of our lives, intricately weaved into our everyday lives.

Our current maintenance approach is targeted to solve present track or train related issues during engineering hours nightly. However, as our rail systems run 365 days without rest, we can no longer rely on traditional maintenance methodologies.

Today, the SMRT-NTU Smart Urban Rail Corporate Laboratory (Corp-Lab) was officially launched by Coordinating Minister for Infrastructure and Minister for Transport, Mr. Khaw Boon Wan.

Corp-Lab is a collaborative platform where SMRT partner academia and fellow industry partners for knowledge exchange. NTU’s scientific and renowned research capabilities; together with SMRT’s operational expertise will help deliver real-life customized solutions that will serve the needs and problems faced by our rail systems.

Till date, we have had success with the introduction of condition monitoring systems through preemptive failure warnings of critical components and systems. For example, the Third Rail Sag Alert system managed to capture 14 warning triggers in 2015.

Going forward, Corp-Lab will focus on two research tracks. The first aims to develop advanced condition monitoring system that will further enhance the resiliency and safety of our network. The second is targeted to enhance overall integrity and reliability of our rail assets.

Through Corp-Lab and NRF’s Corporate Lab @ University scheme, we aim to deliver customized solutions, strengthen our rail network by detecting potential faults earlier and increasing the pool of industry-ready experts.

When we are able to do so, this will translate into smoother and uninterrupted journeys for our commuters in our rail network.

Trains Vs Lightning

We spoke to our engineers to understand how our trains are protected from lightning strikes. Each train is protected by a “Faraday Cage”. This is an enclosure formed by conductive material that blocks electric fields and electric currents such as lightning strikes. The cage conducts current around the outside of the enclosed space with none passing through the interior.

SMRT Train cross section

In this case, the metallic exterior of our trains is the Faraday Cage that protects everyone inside from electric currents. Even if you’re holding onto the grab pole, you will still be safe as grab poles are attached securely to the train’s interior and are not connected to the external frame.  If lightning strikes, the electric current will travel through the outside shell of the train, not through the cabin, and pass through the wheels to the track. The train is grounded to the track.

This process of shielding is used in cars and planes as well.

Lightning Strike on 11 May

You may have read on the news that lightning struck a location between Yio Chu Kang and Khatib Stations along the North-South Line on 11 May 2016. This caused a train fault, affecting commuters travelling towards Yio Chu Kang Station. Commuters on board the affected train were safely disembarked at Yio Chu Kang Station. As a precaution, our engineers also tested the trackside equipment to ensure that it was safe for trains to move over the affected area.

Initial findings show no indication that our train was directly struck by lightning. We suspect that lightning could have hit a nearby area close to the train and indirectly affected the performance of electronics on the train which resulted in a train fault.

Lightning related incidents are a relatively rare occurrence. We have had an average of one or two such incidents in recent years. We would like to reassure all our commuters that our trains are designed to safely protect them in adverse weather conditions, such as lightning strikes.

SMRT Condition Monitoring Technologies

The North-South and East-West Lines (NSEWL) are two of Singapore’s oldest heavy rail lines. These lines carry almost 2.5 million passengers from as early as 6am to around midnight each day.

 

The Challenge

Maintenance teams have only a few hours each night to rectify any infrastructure faults that may cause interruption to train service the following day. Relying solely on the human eye to discover faults across the 200km length of track on the NSEWL would be like searching for a needle in a haystack.

SMRT_Train_Perspective

How do we overcome these challenges?

It was thus important for SMRT to develop a suite of condition monitoring systems to properly observe and gauge the status of the track and other components in the network, enabling maintenance teams to better plan maintenance schedules and priorities.

Multi-function Vehicle (MFV)

Multi-function Vehicle (MFV)

SMRT has been building its capabilities with condition monitoring technologies as early as 1995, with the introduction of the Multi-Function Vehicle (MFV). The MFV can scan long stretches of track, if not the entire line, to collect data that relates to track geometry, rail flaws and other measurements.

In this series of blog posts, we will introduce the rest of the condition monitoring technologies and how they help our maintenance teams.

 

To start off, here are ten quick facts about Condition Monitoring

# 1: Linear Variable Displacement Transducer (LVDT) was introduced in 2013

# 2: LVDT is also referred to as Third Rail Sag Detection System. It monitors the overall alignment of the power providing third rail.

#3: RailVision was introduced in 2009 and uses a combination of image capture and detection systems to identify faults on a track.

#4: RailVision is able to cover the entire NSEWL in a matter of hours. It would have taken days for patrol teams to cover the same distance.

#5: Multi-Function Vehicles (MFV) were first introduced in 1995 and has since been evolved under the Engineering Trains Branch team.

#6: MFV use other systems, such as one that utilises ultrasound technology, to detect rail condition.

#7: The Laser Trolley is one of the newer conditioning monitoring devices. It was introduced last year, in 2015

#8: In order to measure both rails at the same time, the Laser Trolley had to be customized according to SMRT’s specifications.

#9: The small rocks that the tracks rest on are known as the ballast and they have to be monitored as well.

#10: The conventional way for checking the ballast is to dig out and send samples to labs for testing.

Follow our series on Condition Monitoring as we go deeper into each condition monitoring device.

SMRT Mobility Features

Millions of commuters travel on our transportation network daily. Lot’s of us know the stations and interchanges so well that we breeze through them on auto-pilot, with eyes glued to our phones.  Admit it, you and I are guilty of that once in a while. We’ve walked the same route for years and it has become second nature to us.

However, for passengers with disabilities, the daily commute can be a constant challenge.

For someone on a wheelchair, something as small as the 75mm gap between the train platform and the train can be an obstacle to overcome.

There are many accessibility features on both trains and bus networks to help narrow the metaphorical gap that passengers with disabilities experience daily.

 

MRT Train Stations

SMRT Barrier Free Entrance

Barrier-free entrances and exits

In SMRT’s early days, passengers on wheelchairs would have trouble entering our stations as there were only staircases and escalators to reach the concourse levels. Today, all stations will have at least one entrance that passengers on wheelchairs can use.

SMRT Tactile Paving

Tactile paving

The bars and bumps on the ground are known as tactile paving. They are there for the visually impaired, forming a path leading from platform to important places in the station, such as the fare gates. Have you also noticed that the tactile paving always leads to the wider fare gate?

SMRT Larger fare gates

Wider fare gates

Wider fare gates were introduced to allow wheelchairs to pass, as well as bulky items. These gates are bidirectional, making it more convenient for the passenger as they do not need to approach a Station Staff to help them turn the gate to a certain direction.

SMRT Wheelchair entrance notice

Wheelchair indicators and wheelchair-accessible train carriages

At the platform, passengers in wheelchairs should look out for the wheelchair indicators on the platform screen door or platform floor. These indicators reflect where the wheelchair spaces are on a wheelchair-accessible train carriage. There are two such spaces per train. Some trains also have the grab bar closest to the train doors removed, allowing passengers with wheelchairs or strollers to enter the train easily.

SMRT Visual Indicator

Visual indicators

There are also visual indicators for the hearing impaired. The prominent flashing red lights above the platform screen doors indicate when the train doors are closing.

 

Bus Interchanges

SMRT wheelchair accessible bus boarding berth

Special boarding and alighting berths

Special boarding berths at some interchanges were modified for passengers in wheelchairs. Wheelchair bound passengers who wish to board a certain service number can state so via a console at these berths. The next bus will swing by the berth to pick them up.

SMRT Wheelchair accessible bus

Wheelchair-accessible buses

Passengers in wheelchairs indicate their intention to board a wheelchair accessible bus by pressing the blue button next to the exit doors, triggering a special alert to the Bus Captain. The Bus Captain will then deploy the ramp and help the passenger on board the bus.

SMRT Woodlands Interchange Braille Handrails

Braille guidance on handrails

At the new Woodlands Temporary Bus Interchange, there are “signs” in Braille on the handrails to help the visually impaired locate waiting areas.

 

 

SMRT Disruptions 2015- And What We Are Doing

Singapore’s MRT network consists of five different lines and has a total of 118 stations in operation. SMRT operates the North-South Line (NSL), East-West Line (EWL) and Circle Line (CCL). The other lines that complete the network are the North-East Line (NEL) and the latest addition, the Downtown Line (DTL).

Disruptions of more than 30 minutes per km in 2015*
Line Length of line (km) Disruptions of > 30 min in 2015 Disruptions per km
NSEWL 94 7 0.0745
   NSL 45 4 0.0888
   EWL 49 3 0.0612
CCL 35.4 2 0.0565
NEL 20 4 0.2000
*The Downtown Line statistics have been omitted as it has only been in service since 2013 and 2015 (Phases 1 & 2)

In 2015, SMRT had a total of nine service disruptions that lasted more than 30 minutes across its MRT network distance of 129.4km, an average of 0.0696 disruptions per km.

Instead of the absolute number of disruptions of more than 30 minutes, the “Disruptions of more than 30 minutes per km” metric could be a more useful measure of reliability, as certainly the length of the line (plus its age, number of stations, number of trains, number of passengers etc) should factor into calculations of reliability.

Our observations of the disruption statistics of the MRT network notwithstanding, we continue with our efforts to improve overall rail reliability and we are committed to reducing the total number of disruptions.

What SMRT is doing about longer disruptions and power-related issues?

Of the seven NSL and EWL disruptions that lasted more than 30 minutes in 2015, more than half (53%) were traced to power-related issues. The rest were caused by train faults and signal faults. Our efforts to address these faults include the progressive upgrade of older trains and upgrading the signalling system.

In view of the higher passenger carrying capacity that will soon be made possible by the upgrading of the signalling system and the introduction of more new trains in the next two years, the upgrade and renewal of the Power Sub Stations on the NSL and EWL network has been made even more urgent. We have started upgrading and renewing our power network since early 2015. These sub station upgrades will help address the cause of power delays lasting more than 30 minutes when the work is completed by the end of 2018.

The Third Rail System which supplies power to the trains is currently being upgraded to an improved design, which will increase its robustness and maintainability. We began these upgrading works in 2015. We are working on replacing the entire Third Rail system on the approximately 200-km track length (in both directions) of the NSL and EWL by March 2017. As of 12 April 2016, about 27% on the EWL and 6% on the NSL have been upgraded.

SMRT-Infographic-Maintenance Ops Centre-thumbnailAs part of joint efforts to address power-related faults, SMRT and LTA have also consulted experts to improve the resilience of the electricity lines that provide power to MRT trains and stations. (Please click to view the “Independent Advisory Panel completes review of rail power supply system” press release from LTA). SMRT will work closely with LTA to implement these design improvements as part of the renewal programme for the NSL and EWL power system.

Against this backdrop of upgrades, renewal and enhancements to the third rail system and power sub stations, it’s important that we also focus on condition monitoring and predictive maintenance technologies. When fully implemented, our engineers at the Maintenance Operation Centre will be able to leverage on this capability to monitor, predict and pre-empt faults, and attend to them quickly when they do happen.

Trains services at 13 North-South East-West Line stations to start an hour later on Sundays

From 5 June 2016 to 18 December 2016, train services at 13 stations along the NSEWL – Joo Koon to Queenstown on the East-West Line (EWL) and Bukit Gombak to Jurong East on the North-South Line (NSL) – will commence service up to one hour later than usual on Sundays, except on public holidays. Train services at these stations will start by 7am.

Currently, our project teams, track patrol teams and maintenance teams have about three to four hours of engineering hours each night to carry out works to renew and upgrade the system, in addition to carrying out regular maintenance needed for daily train operations. The later opening will enable these teams to gain the equivalent of 29 additional maintenance nights over the 6-month period. This translates into 2,320 more sleepers and an additional 3,230 metres of third rail that can be replaced. The EWL sleeper replacement project is on track for completion in early 2017.

Alternative travel arrangements
Commuters are encouraged to plan their travel to start after 7am on Sunday mornings where possible. For commuters who must travel before 7am, they can use the existing bus services to get to other train stations; or use the Circle Line and Downtown Line to get to the city. SMRT has also arranged for a new parallel bus service to ply the route from Joo Koon to Bukit Gombak in both directions. More information of the new parallel bus service and fares will be made available within the next few weeks.

EWL sleeper replacement work has reached 50% mark
To date, SMRT has replaced half of the 92,000 timber sleepers on the EWL with more durable concrete ones. This steady progress is made possible by the additional 30 minutes every night that our engineers have gained from early closure of some EWL MRT stations since November 2015.

Apart from sleeper replacement, SMRT is also carrying out other rail renewal projects such as third rail replacement and re-signalling along the NSEWL. While the various parts of the track are being renewed, track patrols and maintenance work will continue. The various project teams, track patrol teams and maintenance teams compete for the limited engineering hours available every night between the end of service and the start of service the following day. To accommodate the track access necessary for the engineering teams to carry out these works, SMRT will commence train services at the western sector of the NSEWL up to an hour later every Sunday.

Progress of multi-year, multi-project rail renewal programmes

This is the progress of the multi-year, multi-project rail renewal programmes on the NSEWL as at 12 April 2016:

SMRT - Progress on Rail renewal programmes

Rail renewal works to be carried out safely and in the shortest time possible

Managing Director of SMRT Trains, Mr Lee Ling Wee, said: “Our priority is to ensure rail renewal works are carried out safely and in the shortest time possible to improve rail reliability. Extending our limited engineering hours by an additional hour once a week allows our engineers to gain additional track access to work on their respective projects and carry out maintenance work. All this is done while trains continue to run and serve commuters every day. We seek the understanding and patience of commuters and the general public as we do our very best to complete the various renewal programmes with minimal impact to our train services.”

Commuters are advised to check for travel updates before starting their trip. Information will be available on the SMRT website, SMRT Connect, LTA and SMRT Facebook and Twitter accounts, LTA Traffic News and MyTransport.SG.