issue 9, november 2007

Safety News Issue 09 Safety News Issue 09

Taisei’s approach in managing Safety

Communication system in RTS

Annual Safety Award Convention

2007

Safer road environment for motorcyclist at work zones

Solid waste management on LTA’s construction sites

Safety performance statistics

Issue 9 | ISSN 1793-1665 | November 2007

SAFETYNEWS

9th Annual Safety Award Convention 2007

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Feature articles in this issue

Safety News Issue 09 Safety News Issue 09Safety News Issue 09 Safety News Issue 09

TAISEI’S APPROACH IN MANAGING SAFETY

Introduction

At Taisei Corporation Contract 853 (C853), there has long been a culture of going beyond legal and contractual requirements, resulting in an exemplary safety record for the company. Taisei C853 has achieved the LTA Annual Safety Award Convention (ASAC) Excellence Awards for two straight years in 2005 & 2006. To top it off, C853 emerged as Champion of ASAC 2007 and also clinched the Inaugural Environmental Excellence Award and the Best Theme Presentation Award. What is Taisei’s secret formula for its exemplary achievements? Leadership

For Taisei, the highest priority given to safety is encapsulated in a mantra that is drilled into the minds of all its’ staff. Drawn from the company’s name itself, the mantra, ”TAISEI”, transpires the spirit of the company’s belief in safety.

Setting the highest standard for safety is Taisei’s leadership, which plays a frontline in all operations. With safety as its topmost consideration, Taisei would ensure that its functions such as planning, designing and resources allocation strictly abides by the Plan, Do, Act, Check cycle.

Signing of Safety Commitment by Mr Kiyoshi Masaki.

This is clear even in the way Taisei chooses its contractors. Only those who have good safety records and have demonstrated the required competence levels for the job are awarded for its projects. Taisei also ensures that it sets reasonable time frames and deadlines for the safe completion of works.

This was demonstrated during the assembly and lifting operations of its Tunnel boring Machine where realistic time frames were established in ensuring that the work was carried out safely. Comprehensive Method Statements, Risk Assessments and Safe Work Procedures were developed and every effort was made to communicate this information down the line up to the workers’ level.

• Risk management meeting.

• Safety briefing.

In addition to such measures, Taisei’s winning formula is to promote safety by rewarding contractors and personnel for adhering to safe workplace practices with monthly cash vouchers and awards.

• Safety Promotion.

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Emergency Response Plan

Even though Taisei is constantly prepared for emergency situations and accidents, no effort is spared to ensure all safety precautions are adhered to at all times.

• Regular Emergency Exercises.

Taisei places a high premium in enforcing safety requirements to ensure that there is never a need to resort to an emergency response plan. Planned general inspections and periodic site audits are jointly conducted by the LTA project team and contractors lead by LTA Project Director. This is to ensure that emergency equipment are readily available on site and properly maintained.

• Site Enforcement.

Safety Culture

To infuse safety culture among its workforce, Taisei conducts regular safety training sessions for their employees at all levels including their contractors. These training sessions are part of Taisei’s comprehensive safety plan, drawn up by its Safety Department.

Taisei also strongly encourages whistle blowing, not because it desires the creation of an in-house secret police, but to create a voluntary and confidential reporting scheme for worksite safety. The scheme aims to enhance safety at the worksites by collecting feedback on safety infringements which, if left unchecked, could lead to the occurrence or recurrence of an accident.

Going the Extra Mile

Knowing that the project is situated within residential areas and busy roads, Taisei has added proactive measures to ensure the safety of residents and motorists are not affected by their construction work activities. The noise levels are constantly monitored to ensure that they are well below the legal limits. Mindful of the many dengue outbreaks around Singapore, Taisei takes a forceful approach in weeding out mosquito breeding sites. Daily checks are conducted on all worksites to make sure there are no hidden puddles of water that will encourage dengue breeding.

Taisei has taken extra measures in ensuring that silt discharges as well as oil leaks from machinery will not pollute the public drains and waterways.

In addition, regular dialogue sessions are conducted to update the residents on the progress of works and listen to their concerns relating to safety, health and environmental issues. Such feedback sessions have proven to be useful in achieving a cordial relationship between Taisei and the residents.

• Regular Dialogue Sessions with Residents.

Conclusion

Taisei strongly believes that apart from establishing and enforcing the stringent safety requirements on site, a strong leadership complemented with total commitment of the workforce including their contractors is a prerequisite in creating a strong safety culture that strive for an immaculate safety record. Taisei also recognizes that going the extra mile for safety is not only good for its employees, it also makes good business sense for the organisation.

by T. Suresh KumarHead (SHE) DepartmentTaisei Corporation C853

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TAISEI’S APPROACH IN MANAGING SAFETY


COMMUNICATION SYSTEM IN RAPID TRANSIT SYSTEMS

Introduction

Communication system is an integral part in today’s highly sophisticated and automated rapid transit systems (RTS). Reliable communication systems integrated with monitoring and surveillance capabilities are essential for the efficient and safe operations of our RTS.

This article introduces the major components of a RTS communication system and highlights the functions that they provide.

Typically, the communication system in our RTS comprises the following sub-systems, as depicted in figure below.

• Communication backbone network• Radio system• Closed circuit television (CCTV) system• Public address (PA) system• Telephony and ancillary communication system

COMMUNICATION SYSTEMS IN RAPID TRANSIT SYSTEMS

IntroductionVoice Communications

Communications system is an integral part in today’s highly sophisticated and automated rapid transit systems (RTS). Reliable communication systems integrated with monitoring and surveillance capabilities are essential for the efficient and safe operations of our RTS.

On a train operated by driver, while commuters talk to the train driver through the trainborne intercom system, the train driver makes use of the radio system for his communications with the station/OCC operators.

This article introduces the major components of a RTS communications system, and briefly discuses the functions that they provide.

Typically, the communications system in our RTS comprises the following sub-systems, as depicted in Figure 1.

Communication backbone network Radio system Closed circuit television (CCTV) system Public address (PA) system Telephony and ancillary communication system

Figure 1 – Simplified Block Diagram of a RTS Communications System

Communication Backbone Network

The communication backbone network (CBN) is the communication platform that connects the RTS stations, depot(s) and the operation control centre (OCC). Besides the communications sub systems, other RTS systems such as the supervisory and control system, fare system, travel information system, access management system, etc. also ride on the CBN for their intra and inter systems communications. As it is the communication backbone serving the key RTS systems, the CBN has to be a highly available and reliable network.

Radio System

Besides the CBN, the radio system is the other heavy weight communication sub system for the RTS. The radio system provides the voice and data communication services that cannot be served by the wired means, supporting a variety of RTS operation and maintenance activities and applications such as trackside maintenance, remote monitoring, emergency services, etc.

In the case of a driverless system, operators from the OCC attend to calls from commuters onboard trains through the radio system. The radio system connects the commuters and the OCC, carrying with it essential services such as passenger intercom and public address announcements to the trains, thus enabling the OCC to respond promptly to commuters’ needs.

Figure 2 - Emergency communication button

Leaky Coaxial (LCX) Cables

Trackside radio antenna infrastructure

Station #1

Radio

CommunicationBackbone Network

Node

Other RTS systems, e.g.- SCADA System - Fare System - Travel Information System - etc.

Trackside Equipment

Fibre Optic Rings OCCStation #2

Station CCTV

Station #3 Station #4

Station #N

PATel & Ancillary

Clock

12:02:00

Data Communications

For a manually driven train, operating status of the trainborne equipment is presented to the driver through audio and/or visual indications. He will take the necessary actions should abnormalities be detected. In the case of a driverless system, the same radio communication system used for providing voice communications is usually used for performing remote monitoring of trainborne equipment too. Depending on design, the radio system may be used as the primary or secondary (redundant) link for such purpose. Examples of equipment operating status and alarms that are being monitored are fire/smoke alarms, equipment malfunction/failure indications, etc. Such information would have to be transmitted to the remote OCC in a timely manner for the operator to take the necessary actions.

In addition, OCC operators may also make use of the radio system to trigger the display of pre-recorded messages, or to send live messages in real time to the visual information displays installed on the trains. These displays complement the audio messages provided through the passenger intercom and public address for normal train operation, as well as during incident management.

The information flows on radio communication links on trains are illustrated in Figures 3 & 4.

Data communication TrainborneEquipment

Figure 3 – Communication links on a train with driver

Voice communication (via radio) Voice communication

Commuterson train

TrainDriver

OCC

TrainborneEquipment Data communication

(via radio)

Voice communication (via radio)

OCC

Commuterson train

Communication Backbone Network

The communication backbone network (CBN) is the communication platform that connects the RTS stations, depot(s) and the operation control centre (OCC). Besides the communication sub systems, other RTS systems such as the supervisory and control system, fare system, travel information system, access management system, etc. also ride on the CBN for their intra and inter systems communication. As it is the communication backbone serving the key RTS systems, the CBN has to be a highly available and reliable network.

Radio System

Besides the CBN, the radio system is the other heavy weight communication sub system for the RTS. The radio system provides the voice and data communication services that cannot be served by the wired means, supporting a variety of RTS operation and maintenance activities and applications such as trackside maintenance, remote monitoring, emergency services, etc.

Voice Communications

On a train operated by driver, while commuters talk to the train driver through the trainborne intercom system, the train driver makes use of the radio system for his communication with the station/OCC operators.

In the case of a driverless system, operators from the OCC attend to calls from commuters onboard trains through the radio system. The radio system connects the commuters and the OCC, carrying with it essential services such as passenger intercom and public address announcements to the trains, thus enabling the OCC to respond promptly to commuters’ needs.

• Emergency communication button.

Data Communications

For a manually driven train, operating status of the trainborne equipment is presented to the driver through audio and/or visual indications. He will take the necessary actions should abnormalities be detected.

In the case of a driverless system, the same radio communication system used for providing voice communication is usually used for performing remote monitoring of trainborne equipment too. Depending on design, the radio system may be used as the primary or secondary (redundant) link for such purpose. Examples of equipment operating status and alarms that are being monitored are fire/smoke alarms, equipment malfunction/failure indications, etc. Such information would have to be transmitted to the remote OCC in a timely manner for the operator to take the necessary actions.

In addition, OCC operators may also make use of the radio system to trigger the display of pre-recorded messages, or to send live messages in real time to the visual information displays installed on the trains. These displays complement the audio messages provided through the passenger intercom and public address for normal train operation, as well as during incident management.

The information flows on radio communication links on trains are illustrated in the figures below.

• Communication links in driverless train.

• Communication links on a train with driver.

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TrainborneEquipment

Commuterson train

Train Driver OCC

Voice communication Voice communication (via radio)

TrainborneEquipment

Commuterson train

OCC

Data communication(via radio)

Voice communication(via radio)

• Simplified Block Diagram of a RTS Communication System.


TETRA Radio systems implemented in our MRT systems are based on the TETRA (Terrestrial Trunked Radio) standards defined by the ETSI (European Telecommunication Standards Institute) and is widely used in many industries, e.g. safety, security and transportation.

One key performance criterion of the radio system is to ensure that staff and emergency response services can communicate with the OCC in its coverage. In tunnels, consistent radio coverage is provided through the use of the leaky coaxial (LCX) cables, whereas a combination of LCX cables and spot antennae are

used on viaducts as well as in stations, depots and OCC, at both public and non public areas.

• Example of LCX cables installed in tunnel.

Closed Circuit Television System

In an automated rapid transit system, especially one with unmanned stations, operators make use of the CCTV system to monitor passenger flow, passenger safety and station security. Cameras, majority which are of the fixed lens type, are strategically positioned to achieve surveillance coverage of specific areas with sufficient details. In today’s context, CCTV cameras, together with digital recording facilities are also installed for security reasons – to serve as deterrence, as well as to provide useful evidence for post incident investigations.

• Station and Trainborne CCTV Cameras.

While most of the cameras would be station-based, depending on operational needs, track to train CCTV system which allows the train operator to view the status of the platform edge/train door interface, or trainborne CCTV system which provides remote surveillance of moving train interiors are also installed as part of the CCTV system.

Public Address (PA) System

The PA system is one that has direct interface with the commuting public on a daily basis. It is used by the operators to relay information and direction to the commuting public, either during normal RTS operation, or under emergency situations.

The PA system is also interfaced with the fire alarm system to broadcast pre-recorded coded and alarm messages under pre-defined conditions, and to temporarily cut off the alarm bells in non public areas (if activated) so that PA announcements can be heard.

• PA speakers at platform edges uniformly spaced to provide uniform sound coverage.

Telephone & Ancillary Communication System

Telephone switches (PABX, private automatic branch exchange) are implemented in our RTS systems to provide the voice communication required for RTS operation and maintenance, as well as for passenger service purposes.

Two-way voice communication facilities required by the SS CP25 and “Standard for Fire Safety in RTS” are also implemented in the RTS for fire safety purpose. These include the two-way emergency voice communication designated for public and SCDF use, e.g. the emergency fire phones, firemen intercoms, etc.

Direct lines (hotlines) between key points such as passenger service centres of interchange and integrated MRT stations, hotlines between OCC of different MRT lines, hotlines between OCC and emergency/fire service departments, etc. are other voice communications that are installed to provide instant and uninterrupted voice communication for RTS operations.

In addition, help points are also installed in our RTS for use by the commuters.

• Emergency telephone on NSEW MRT station platform.

Two-way voice communication facility is also provided at Blue Light Stations (BLS) that are installed at locations such as station head-walls, tail-walls, tunnel cross passages and emergency access for

communication with PSC/OCC.

Conclusion

The RTS communication system puts together a suite of voice and data communication facilities that are required for the RTS operation, maintenance, safety and security purposes.

A reliable, effectively and efficiently managed communication system is the key to an efficient and safe operation of today’s RTS systems.

by Tay Lim Hock Manager (Communications)

Signals, Communications & Control Division

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COMMUNICATION SYSTEM IN RAPID TRANSIT SYSTEMS

Safety News Issue 09 Safety News Issue 09Safety News Issue 09 Safety News Issue 09Safety News Issue 09Safety News Issue 09

Introduction

LTA hosted its 9th Annual Safety Award Convention (ASAC) 2007 at the Singapore Polytechnic Convention Centre on 24th August 2007. This year, thirty-one LTA contractors participated in the Convention.

The Convention, started in 1999, is to give recognition to contractors who are most proactive in implementing high-standard safe work practices for safety and health, including the welfare of their workers and the public, while at the same time giving due consideration to protecting the environment.

Speech by Guest-of-Honour

The guest-of-honour, Minister of State for Finance and Transport, Mrs Lim Hwee Hua shared her belief that everyone, (among others include regulator, developer, consultant, contractor, supplier, workplace safety and health professional, project manager, supervisor as well as on-site-worker), has a vital role to play in creating a safe and healthy work environment.

She commended LTA for their commitment in creating a safety culture in Singapore’s land transport construction projects. She also noted that LTA had engaged DuPont Safety Resources, a reputable safety consultant to assess its Occupational Safety and Health Management System and achieved a score of 3.7 out of a possible 5 for world class excellence based on DuPont’s audit scoring system. In concluding her speech, she urged all LTA contractors to emulate the finalists and winners of the Convention to work towards an accident-free work environment.

• Guest-of-honour, Mrs Lim Hwee Hua, Minister of State for Finance and Transport.

Theme of ASAC 2007

The theme of the Convention “Heavy Lifting Operation – Managing Safety Beyond Legal and Contractual Requirements” was chosen to promote safe lifting at all LTA worksites in view of the serious implications arising from the lifting incidents. Following the finalists’ presentation, a skit was jointly performed by LTA staff and Contractors’ representatives to drive home the safety message that both LTA and Contractors have a complementary role in spearheading safety standards in the workplace.

• Safety Skit performed on stage.

• Skit Finale - LTA Senior Management staff singing a song to drive home the safety message.

Categories and Awards

This year’s competition was divided into four categories:

Minor category Civil contracts with value < $20 million

E&M category E&M contracts with value ≥ $20 million

Major category Civil contracts with value ≥ $20 million but < $50 million

Mega category Contracts with value ≥ $50 million

The participating contractors from the E&M, Major and Mega categories undergone a twelve-month period of monthly Environmental, Safety and Security(ESS) assessment conducted by LTA project teams and one round of internal site audit. Four finalists were short-listed from the Mega category to compete for the Contractor’s Challenge Shield. This would require them to be audited by an external panel of judges and to put up a presentation on the day of the Convention. The panel of judges comprised senior representatives from the Ministry of Manpower, the Building and Construction Authority, the Singapore Contractors Association Ltd, the Singapore Institution of Safety Officers and Merck Sharp & Dohme (S) Ltd.

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ANNUAL SAFETY AWARD CONVENTION 2007

Safety News Issue 09 Safety News Issue 09Safety News Issue 09 Safety News Issue 09Safety News Issue 09

• Panel of Judges (L-R): Mr Yeong Chark Sung (MOM), Mr Ding Hock Hui (BCA), Mr Richard Tan (SCAL), Mr Ong See Hee (Merck, Sharp & Dohme) and Mr T Gopalakrishna Rao(SISO).

The scoring criteria were 80% based on the results of the site audit and 20% on the presentation at the Convention.

A total of sixteen awards and a Challenge Shield were presented to the contractors and a Project Safety Commendation Award was presented to the LTA project team during the Convention. These were as follows:

• The LTA Contractors Challenge Shield to the winner of the Mega Category.

• Certificate of Excellence to the four finalists of the Mega category and the winner of the E&M and Minor categories with outstanding safety performance.

• Certificates of Merit to the six contractors from the Mega, Major and E&M categories for demonstrating consistently good safety performance over the assessment period.

• Project Safety Commendation Award to the LTA Project Safety Committee with the best effort in ensuring and promoting excellent safety and health standards at its worksites. Circle Line E&M Project Safety Committee won the award.

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The 2 new awards presented for the first time at ASAC 2007 were:

• LTA Construction Environmental Excellence Award to three contractors who have shown outstanding environmental management at the worksites.

• Certificate of Best ASAC Theme Presentation to the finalist of the Mega Category who has delivered the best presentation on the ASAC theme.

Safety News Issue 09

Certificate of Excellence

Project Safety Commendation Award

The Winner of ASAC 2007

•Mega Category – Alstom Transporation S.A., Alstom Transport (S) Pte Ltd and Singapore Technologies Electronics Ltd Consortium, Contract 830.

•Mega Category – Woh Hup Pte Ltd – Shanghai Tunnel Engineering Co, Ltd – Alpine Mayreder Bau GmbH Joint Venture, Contract 855.

•Mega Category – Sembawang Engineers and Constructors Pte Ltd, Contract 856.

•Minor Category – Feng Ming Construction Pte Ltd, Contract ER189.

•E&M Category – Keppel Seghers Engineering Singapore Pte Ltd, Contract 413.

•Mr Sim Wee Meng, Group Director (Rail) and Director (CCL E&M) receiving the Project Safety Commendation Award from Chairman of LTA, Mr Michael Lim Choo San.

•Mr Akira Nakano, representing Taisei Corporation, Contract 853 receiving the LTA Contractors Challenge Shield and Certificate of Excellence Award from Guest-of-honour, Mrs Lim Hwee Hua, Minister of State for Finance and Transport.



LTA Construction Environmental Excellence Award

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by Yoong Yew MengExecutive, Safety and Health

Safety Division

Certificate of Merit

Best ASAC Theme Presentation

•E&M Category – Windhoff Singapore Pte Ltd, Contract 836.

•Major Category – Evan Lim Co Pte Ltd, Contract ER157.

•Mega Category – Nishimatsu Construction Co Ltd, Contract 828.

•Major Category – Hock Lian Seng Infrastructure Pte Ltd, Contract ER158.

•Mega Category – Taisei Corporation, Contract 854.

•E&M Category – Tyco Fire, Security and Services Pte Ltd, Contract 414.

•Taisei Corporation, Contact 853.

•Tasei Corporation, Contract 853.

•Lam Chuan Construction Pte Ltd, Contract ER185.

•Tasei Corporation, Contract 854.



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Introduction

Motorcyclists are a vulnerable group of road users that account for over 50% of fatalities in road accidents over the past years.

• Motorcyclist travelling through the work zone.

It is essential that projects involving temporary traffic control implement good engineering measures in accordance with Code of Practice for Traffic Control at Work Zone (COP) to provide a safe road environment for all road users. In this issue, we will highlight practices that can be implemented to enhance the safety of motorcyclists.

Road Surface

The road surface is critical to the safe riding of motorcyclists. Motorcycle has a greater need for a consistent and high surface friction or skid resistance than four-wheel vehicles, especially on wet surfaces and bends that require extra braking and steering. Temporary steel plates covering over trenches or decking installed over excavated area must have comparable skid resistance to the existing road surface. Clean and debris-free road surface should be maintained at all time as loose gravel and sand debris cause a loss of traction between the tyres and road pavement. Uneven surface after patching of road pavement following utility trenching works or excavations of roads should be levelled up quickly as to minimize motorcyclists from losing balance.

• Steel decking overlaid with skid resistant material that is comparable to road surface.

• Smoothly patched surface in road pavement provides a safer ride.

Visibility

Good forward visibility allows for timely detection of hazards ahead and reduce incidence of hard braking by motorcyclists that could lead to loss of control situations and fall. Visibility can be improved by increasing the radius of the realigned road or setting back the hoarding away or eliminating obstruction (excessive vegetation, signs) from the curved section of the road. Low hoarding could enhance visibility at road junction.

• Hoarding set back away from road edge improves visibility.

SAFER ROAD ENVIRONMENT FOR MOTORCYCLISTS AT WORK ZONES

Continued on page 10

I’ll forego my beer for

SAFETY!

During the festive season, if you drink don’t drive.


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Street Furniture

Motorcyclists have a tendency to ride between the vehicles as well as the gap between vehicles and road kerb. Roadside furniture (signs and posts) located close to the roadway can be a hazard if the motorcyclist loses control and crash into them. To mitigate this hazard, the number of signs and posts should be kept to a minimum. An appropriate offset should also be provided between the signs/posts and the edge of the carriageway as recommended in the COP.

• Keep number of signs to a minimum and provide appropriate offset from road edge as required by COP.

Curved Section of Road

Stability is a critical issue to a 2-wheeler as compared to other vehicles. Motorcyclists are potentially less stable when they ride on the curved section of road which requires them to change path and speed. Any sudden change in speed from a tighter bend can lead to a loss of surface grip between tyres and roadway, causing the motorcyclist to skid and lose control.

• Desirable to have road with generous radius.

It is desirable to design road with the radius as specified in LTA Design Criteria around the work zones. Where there is site constraint, proper advance warning signs and good delineation should be installed to warn and guide motorcyclists to navigate the curved section safely. In addition, the provision of a clear zone free of obstructions/hazards at these locations could reduce injury to the motorcyclists in situation of running-off road and falling off their machine.

Conclusion

All the practices discussed have been considered in the COP. Therefore, project team carrying out roadwork should adhere strictly to the guidelines as described in the COP to provide a safe road environment for motorcyclists and other road users travelling through the work zones.

by Chris Loh Kok FahSenior Engineer, Safety

Safety Division

SAFER ROAD ENVIRONMENT FOR MOTORCYCLISTS AT WORK ZONES

• Low hoarding enhances visibility at road junction.

Adequate street lighting is also vital at work zones during the night for the following reasons:

• Motorcycle headlight illumination spreads over a limited area ahead of the vehicle as the rider manoeuvres along the alignment of the road. The objects and delineation are not as visible to motorcyclists at night time as they are to car drivers.

• Motorcycles are narrow and typically have a single headlight, making it less conspicuous to other road users and harder to judge their approach speed especially during the night.

Safety News Issue 09

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SOLID WASTE MANAGEMENT ON LTA’S CONSTRUCTION SITES

Introduction

Solid waste is broadly defined as any unwanted substance or material solid in nature requiring disposal. In most construction sites, solid wastes such as timber, metal scraps and hardcore are often generated as unwanted by-product of the process. As an environmentally responsible developer, we need to minimise the generation of these construction wastes.

• Typical waste generation from a construction site - Demolition debris.

Waste Disposal Construction wastes are non-incinerable and will be sent directly for landfill if there is no effort to control.

The current only landfill site for Singapore is the Semakau Landfill and it has a holding capacity of 63 million cubic feet. The landfill site was formed by linking Pulau Semakau and Pulau Sakeng to form a concrete bund lined with impermeable membrane. Additional measures are put in place to ensure no leakage of leachate into the marine waters. The landfill was completed and commenced its operations in year 1999 with an estimated lifespan of 45 years.

• Picture of Semakau Landfill (Adapted from NEA, Article on “Semakau Landfill and Tuas Marine Transfer Station”).

If waste are not minimised and controlled, the landfill would not be able sustain our consumption habits and another landfill needs to be sought after.

Landfill - the ultimate solution?

Landfills are not the ultimate answer to how to manage our waste. Firstly, landfills will generate leachate which is toxic to the environment. The after-effect of a landfill site would be the generation of toxic gases like methane. These gas formations could render our land uninhabitable. For example, the after-effects of a landfill can be seen at project ER158. Toxic gases have been formed where the old landfill site was. Proper venting has to be carried out and proper PPE has to be worn by the team when they are developing the land parcel on top of the Lorong Halus landfill site.

Secondly, Singapore as we all know is a land-scarce country and every bit of land is precious. Land is required for developing infrastructures and homes for everyone including native fauna and flora. It will get more challenging to find new locations for incineration plants and landfill sites that will not adversely affect our population and environment.

(Adapted from: “http://www.hpsupplies.info” www.hpsupplies.info).

Landfill approach is a reactive measure and not sustainable. What we should be advocating is “Source Control” which is solving the problem from the upstream decision-making stage.

Continued on page 12


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During the operational phase, workers or operators should try to:

Reduce the production of wastage as much as possible. For example, the cutting of steel rebar can be controlled to reduce as much cut wastage as possible.

Reuse is to put the wasted material in its original form into another application. For example, the re-usage of milled waste for paving operation.

Recycle is to alter the state of a particular waste into another useful form, typically due to additional processes needed; recycling involves the expenditure of energy like chemical or mechanical energy. For example, when we recycle the timber waste into paper, we need to exhaust chemicals to wash and mechanical energy to mill the timber to convert them into recycled paper. Recycling is not considered first due to this additional amount of energy that needs to go into its operation compared to Reduction and Reuse.

Disposal will be the last to be considered due to the amount of land it requires to landfill and the residual effects that landfilling will cause on the land.

Effective Solid Waste Management System at LTA’s Site

Let us examine on how the above methodology applies on our construction sites. An effective solid waste management system at site should include but not limited to the below few points.

1.

2.

3.

Waste Management

When waste is unavoidable, there should be a proper Waste Assessment system for reuse and recycle to identify which waste goes to which process.

There should be a system of Waste Separation to ensure no cross contamination of waste. Cross contamination most likely leads to a degradation in the quality of waste. When there is cross contamination, extra resources and energy must be pumped into separation processes which explain the increased cost of disposal of mixed refuse from categorised waste. Cross contamination

1.

2.

might also render the waste totally non reusable or recyclable.

Proper storage facilities should be catered for to ensure containment of waste from pests and natural elements. Proper waste containment reduces the energy expenditure in treatment for example, wastes with high moisture content (exposed to rain and shine) requires more energy to incinerate than waste with low moisture content (adequately contained waste).

Proper information and recording system should be instituted to ensure standardised treatment and tracking of waste.

Proper housekeeping of storage sites should be maintained to cleaner sites and eliminate any breeding sites for dengue mosquitoes.

3.

4.

5.

Conclusion

Uncontrolled solid waste disposal will cause environmental damages not visible to us. Its impact is often chronic like cigarette smoking; wastes can fill the land similar to tar that accumulates in a smoker’s lung. We have a challenge to change our way of living as well as our way of managing projects moving towards a more sustainable manner.

by Chan Cheong ShuenEngineer, Environmental

Safety Division

SOLID WASTE MANAGEMENT ON LTA’S CONSTRUCTION SITES

Waste Management Methodology

All waste management follows the approach as highlighted in the figure below.

The figure above should be read with the highest priority starting from the base of the pyramid. Disposal option should always be considered last.

As far as possible, eliminate wastage at the design stage. Solid waste generation should be considered when you are making a buying decision. Decision should factor in waste management with other considerations such as price, quality and etc. For example, projects can design to employ the use of metal instead of timber formwork to eliminate the production of timber waste during and after the project.

Waste Reduction

During the design stages, as far as possible, due considerations should be taken to manage resources with minimal wastage in mind.

All operations should be analysed and those which have a potential of generating wastage should be controlled with an appropriate control system. For example, cutting of steel rebar should be controlled to reduce error in cutting thereby reducing the production of waste.

A system for Inventory Management to track resource flow in order to minimise wastage from over purchase should be established.

Hierarchy of Solid Waste Management in Singapore’s context

Direction of increasing priority


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ACCIDENT* STATISTICS FROM JANUARY 2007 TO OCTOBER 2007

*Based on Workplace Safety and Health Act Requirements

Safety News Issue 09 Safety News Issue 09EDITORIAL PAGE

Construction Staff Safety Award (CSSA) on 14 November 2007

The annual CSSA gives due recognition to LTA officers who have demonstrated pro-active attitudes and exemplary safety conscious efforts towards safety and health issues at their workplace.

“All cranes at LTA worksites have to undergo 6 monthly

inspections by an Authorised Examiner (AE).”

Safety Ong says...

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Safety Division251 North Bridge Road, Singapore 179102

Tel: (65) 6332 6139 Fax: (65) 63326129 Email address: [email protected]

Safety News is also available online at http://internet-stg.lta.gov.sg/Projects/index_proj_safety.htm

Editorial Committee

Advisor Corporate Safety Committee

Editor• Patrick Lee

Circulation Officer• Tan Chee Lang

The CSSA winners with LTA senior management, from L-to-R: Mohamad Ezan Bin Ahmad (CCL E&M), Lim Swee Heng (C856), Ng Sing Kwong(C852), Husain Khanali Ratlamwala (C855), CE BG Yam Ah Mee, DCE Lim Bok Ngam, GDSC Frederick Wong, Darwin Garcia Edangal (C828), Abdul Jabbar Bin Sulaiman (C421) and Kerk Eng Huat (ER157).

Not in picture: Ng Seng Thiam (C1280) and Loo Sai Kiang (C9001).

Million Accident Free Man-hours

Congratulations to our Contractors for achieving 1 million accident free man-hours for the period from May to October 2007;

Woh Hup Pte Ltd – Shanghai Tunnel Engineering Co, Ltd – Alpine Mayreder Bau GmbH Joint Venture, C855.

Sembawang Engineers and Constructors Pte Ltd, C856.

Writers• Chan Cheong Shuen• Chris Loh Kok Fah• T. Suresh Kumar• Tay Lim Hock• Yoong Yew Meng

MOM Workplace Safety and Health Awards 2007

Congratulations to the following LTA projects for achieving the MOM Workplace Safety and Health Awards 2007.

Workplace Safety & Health Performance Awards (WSHPA) – SilverWH-STEC-NCC JV, C825.

Safety and Health Award Recognition for Projects (SHARP) Woh Hup Pte Ltd – Shanghai Tunnel Engineering Co, Ltd – Alpine Mayreder Bau GmbH Joint Venture, C855.

Sembawang Engineers & Constructors Pte Ltd, C856.

Safety Management Observation training conducted by DuPont - 13 to 15 Nov 2007.

issue 9, november 2007

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