Introduction. In January 2007, LTA appointed DuPont Safety Resources to ....
Encourage use of panel clinics. 6. 7. .... Case Example of Equipment Failure.
SAFETYNEWS Special Edition | ISSN 1793-1665 | August 2007
SAFE LIFTING OPERATIONS
Dupont’s Audit of LTA’s OSHMS and LTA’s Safety Retreat
02
Creating Safer Work ZonesProviding Good Visibility
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Control of Cranes at LTA Worksites
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‘No Flood, No Silt’ Friends of Water
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Thematic Exercise on ‘Safe Lifting 06 Operations’ at LTA Worksites
Control of Bored Piling Noise at LTA Project Sites
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DuPont’s Audit of LTA’s OSH Management System & LTA’s Safety Retreat
>> Introduction In January 2007, LTA appointed DuPont Safety Resources to conduct an assessment on its Occupational Safety and Health Management System (OSHMS). LTA’s OSHMS was assessed based on DuPont’s Criteria for Excellence in Safety. A similar audit was also conducted by DuPont in 2003. Auditor from DuPont, Mr. James O. Faulk, conducted interviews with LTA’s top management and project management teams and visited various LTA worksites during the audit period.
that contractors who work safely are better equipped to meet their cost, schedule and quality commitments.
World Class Excellence Skill Fundamentals Awareness
DuPont auditor visiting a LTA worksite and presenting at the closing meeting.
LTA achieved an overall rating of 3.7 out of a possible 5 for world class excellence. In simpler terms, it means that LTA executes most of the best practices in occupational safety and health (OSH) routinely and consistently.
Chart 1 : DuPont’s audit scores on LTA’s Occupational Safety & Health Management System
Periodic/Post Contract Evaluation also scored very well at a rating of 4.5 (Excellence). Credit for this is largely due to the introduction of the Safety Performance Scheme within LTA projects back in 2004. The scheme is a “carrot and stick” approach that LTA believes will lead to better safety performance through more effective self-regulation on the part of contractors.
Notably, there are improvements in the scoring of all of the 17 audited elements as compared to the 2003 audit findings. The good results are the fruits of hard work that LTA has put forth in pursuit of excellence in management of OSH at LTA within all working levels. With reference to Chart 1, LTA scored a rating of 5 (World Class) in Effective 2-Way Communication. The auditor was most impressed by LTA’s Project Safety Review process for civil projects which seeks to integrate safety and health issues into project planning and management, right from the design stage, through the construction and maintenance phases and eventually to its demolition, so that everyone can discharge his/her duties effectively. In addition, having comprehensive tender specifications for OSH, regular meetings and dialogue sessions with its contractors on OSH matters are among the positive factors that contributed towards the world-class rating.
LTA offers $1 million safety carrot Rewards for contractors with excellent safety records and penalties for those with poor standards in new rail contracts The Straits Times - 13 May 2004
Nevertheless, numerous areas for improvement had been identified and recommended during the audit. A key recommendation by DuPont was to “assemble the new management team (top management) for a one day meeting to discuss setting a safety goal for 2007 that shows year over year improvement in performance”. In view of this important recommendation, LTA held its first Safety Retreat on 26 March 2007 at the British Club, involving its top management, the engineering and the project management teams to chart the direction for safety and health excellence within LTA for the years ahead.
Contract Award scored very well at a rating of 4.5 (Excellence). Assessing the safety management system, OSH track records and risk management techniques of tendering contractors are mandatory for all construction projects before contracts are awarded. However, DuPont strongly recommended that government ministries increase the Quality component of the tender assessment to around 30%-40% (currently 20%) and the Price component being in the range of 60%70% (currently 80%) to send a clear signal to contractors that we value the safety of its workforce and recognise 2
Group photo of participants at the Safety Retreat
>> Yearly Corporate Targets 5. Encourage use of panel clinics. 6. Reduction of falling from height cases. 7. Reduction of hand/finger related injuries. 8. Review of design works / buildability.
Chart 2 : Yearly Corporate AFR & SR targets 2007 - 2009
Chart 2 shows the targeted yearly improvement of the corporate figures for Accident Frequency Rate (AFR) and Severity Rate (SR) from 2007 to 2009. Recognising that every person at the workplace deserves to return home safely, participants reaffirmed their commitment towards “ZERO FATALITY” in LTA projects.
Participants engaging in detailed discussions
>> Safety Initiatives
Summary
>>
To achieve the targets for future years, the participants agreed that new and bolder strategies have to be implemented at LTA to bring management of OSH to greater heights. The following is a summary of the strategies that were put forth and are currently being studied by the work groups who volunteered to champion them at the safety retreat:
Safety and health is everybody’s responsibility and every single effort counts toward achieving the stated objectives. It was acknowledged at the safety retreat that the performance review process should also address positive or negative contributions to safety and health performance, which was also one of the key recommendations put forth by DuPont.
1. Enhancement to existing Safety Performance Scheme through the monthly Environmental, Safety and Security assessment on Contractors.
While the DuPont audit allowed LTA to gain an external viewpoint and benchmark, the safety retreat had allowed participants to appreciate how the safety performance of each project works toward the corporate targets, and the need to continuously challenge ourselves to set more challenging targets for continual improvement. In summary, both the audit and safety retreat had been valuable in charting the future direction for safety and health excellence within LTA.
2. Improve communication and information flow within Contractor’s supervisors/workers. 3. Investigation of near miss cases. 4. A.L.E.R.T. : Aware of nature, Learn to discern, Evaluate situation, Respond appropriately, Track work progress while ensuring safety and health compliance.
by Tan Hock Seng Andrew Safety & Health (Info/Promo) Manager Safety Division
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Control of Cranes at LTA Worksites
>> Introduction Apart from these requirements, efforts were beefed-up during routine inspections conducted jointly between LTA project teams and contractor’s site management team on lifting operations.
Lifting operations involving the use of cranes are commonly sighted at construction worksites. These lifting machines are designed and ‘tailored’ for specific use and come in a wide range of sizes; from the articulate arms of the lorry loader to the large and sophisticated cranes used to build oil rigs and salvage sunken ships.
Thematic exercises such as ‘Safe Lifting Operations’ are also conducted regularly by LTA’s Safety Division. These site audit exercises allow the auditors to scrutinise in depth into the controls of cranes and other lifting machines being used at the worksite. Strengths and weaknesses identified during the exercises are then brought to the attention of the project teams across the island who would then share the findings with their contractors.
The usage of cranes at construction worksites have also brought about greater flexibility in construction methods and design concepts. Construction activities can now be planned to take advantage of the greater versatility and capability of these machines. However, its extensive use has also brought about concerns over the safety of such machines, especially when used near public areas.
>> The Need for Strict Control On 26 October 1999, a mobile crane toppled with its telescopic boom crushing through the site hoarding and landed onto a passing car. In another similar incident, on 13 May 2000, a crawler crane toppled and the fallen boom crushed through the site hoarding and landed onto the carriageway. Fortunately, except for some minor injuries on the crane operators, nobody else was injured in these two incidents.
Thematic exercise on lifting operations being conducted on-site.
26 October 1999
This section will take you through an analysis of crane-related toppling incidents (also known as Dangerous Occurrences under the Workplace Safety and Health Act) at LTA worksites using data from LTA’s Safety Information Management System (SIMS), which is a one-stop resource-efficient portal for quick retrieval of information on safety performance trends. The system allows the storage, sharing and analysis of accidents and incidents which had occurred on LTA’s worksites since 1998.
13 May 2000
These incidents vividly demonstrated the risky business of operating cranes near public areas. Since then, LTA had, in consultation with the Crane Association of Singapore, put in more stringent control on the usage of cranes at its worksite. This came about through a total revamp of LTA’s general contract specifications for lifting operations in 2001. The new specifications cited stringent controls which included : • Setting the minimum work experience of the lifting engineer and crane operator. Imposing a 15 year old limit (from date of manufacture) for all types of mobile cranes used on its worksite.
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Requiring the provision of Load Radius Indicator for all lifting machines with a Safe Working Load > 1 tonne.
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Requiring lifting machines to be thoroughly examined by an Approved Person (now known as Authorised Examiner) at least once every 6 months.
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No. of Cases
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4 3 2 1 0
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
Year (Note: Intervene Actions were Introduced In 2001) Human Factor
• Requiring the development and communication of lifting plan for every lifting operation.
>>
Review of Dangerous Occurrences
Chart 1 : A comparison of Dangerous Occurrences
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Equipment Failure
28 cases of DOs, recorded from 1998 to present, were reviewed. They were categorized into either ‘Human Factor’ or ‘Equipment Failure’. Human Factor includes lack of relevant experience, poor judgment of the load, lifting on unstable ground, deliberate risk taking by the crane operator and et cetera. Equipment Failure includes wear and tear, fatigue failure of hoist ropes, boom members, sheaves and et cetera. The results were also used to gauge the effectiveness of the intervention measures that were introduced in 2001.
Human Factor accounted for almost 70% of DO cases recorded and the intervening measures have had little or no success. Noting this trend, LTA has been working with its contractors to ensure additional control measures are in place to check and mitigate the risk of human lapses. These measures include: •
pad-locking of bypass switches to prevent deliberate risk-taking
>> Case Example of Equipment Failure
A 50 ton crawler crane was being used to lift up a load weighing approximately 650kg. At that particular working radius, the crane has a Safe Working Load (SWL) of 6 tonnes. While slewing the load, the operator experienced a loosening and malfunctioning of the boom control lever. The hoist rope snapped and the boom crushed onto a stock pile of construction material. The crane’s boom was damaged and fortunately nobody was injured.
Padlock of bypass switches
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strict adherence to ‘Permit to Work’ system to ensure strict control of lifting operations
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tool box meeting is conducted prior to any lifting operation
Referring back to Chart 1, DOs due to equipment failure had the highest success rate when the intervention measures were implemented. There were 7 cases prior to intervention and this had dropped significantly to 2 cases after stricter controls were implemented.
Pre-lift briefing in progress
A crane operator was tasked to lift a cylindrical metal casing used for bore piling. The operator by-passed the OverDerricking Limit Switch and allowed the boom to be raised beyond its derricking limit. As a result, the boom stopper broke and the boom collapsed backwards and rested on the operator’s cabin. Nobody was injured in this incident.
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regular safety awareness talks/programs to lifting crew
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issuing of safety alerts on related topics
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debarment of personnel who flout safety rules at LTA worksites
Conclusion
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>> Case Example of Human Factor
As cranes have become indispensable at our construction sites, stringent controls must be set in place to regulate their use. It is easier to implement control measures to deal with equipment failure as observed from the results. However, human error comes in many forms and is much harder to control. Complacency should not set in; time and efforts must be continuously spent to educate all lifting-related personnel on the importance of proper risk assessment and strict controls during lifting operations. In addition, lifting operations should not be solely left in the care of lifting supervisors or crane operators. These operations must be carefully planned by Lifting Engineers or competent persons who possess the requisite knowledge and experience in managing such tasks.
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by Lee Ngee Hock David Executive, Safety & Health Safety Division
Thematic Exercise on “Safe Lifting Operations” at LTA Worksites
>> Introduction ❖
In 2001, LTA embarked on an initiative known as “Thematic Exercise” aimed at improving its safety performance. This exercise is different from the regular site inspections with focus on a specific theme which undergo thorough evaluation. Potential weaknesses identified would be brought to the prompt attention of our contractors for their immediate rectification, thereby eliminating the likely occurrence of an accident or incident.
Appropriate 2-way means of communications between the crane operator and the lifting teams via walkie-talkie are in place. In any situation where electronic communication was not available, the signalman would position himself to maintain visual contact with the crane operator.
The theme-based exercises are pegged to the various phases of construction works on site. Through focusing on specific risks identified at each phase, these exercises ensure that risk control and mitigating measures are in place and complacency does not set in. It also helps to increase the safety awareness of contractors and their workers for their full compliance to legal requirements as well as LTA’s General Specifications (GS) for Safety, Health & Environment. Recently, in June 2007, LTA’s Safety Division conducted a thematic exercise at Circle Line MRT Stages 4 & 5 on “Safe Lifting Operations” as the project is still largely in its excavation phase, with extensive heavy lifting operations. This article aims to share with our readers on some findings from the exercise. Signalman communicates with crane operator via walkie talkie and hand signals
>> Key Findings Good Practices/Compliances
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A total of 22 cranes were thoroughly checked for compliance with legislative requirements and LTA’s GS requirements. Compared to similar exercises carried out previously, many of our contractors are now more aware of our stringent controls and have put in concerted efforts to comply with our contractual requirements. Some of the notable findings were as follows :
All the cranes used on site were found to be in compliance to LTA’s requirements to be not more than 15 years old from date of manufacture.
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The auxiliary load-line was tested by Authorised Examiners (AE) and the results were reflected in the Lifting Machine (LM) certificate.
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Monthly colour coding system for all lifting gears were in place. LTA project teams also conducted ad-hoc checks to ensure only lifting gear with valid certificate are paint-marked and used on the worksite.
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Throughout the entire exercise, all lifting operations were noted to have been carried out in accordance with safe and sound practices.
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There were sufficient Lifting Engineers appointed to coordinate lifting operations that are supervised by the Lifting Supervisors. In addition, lifting plans were also prepared by these engineers to ensure that the accesses and ground conditions (footing) are taken care of with due consideration for the stability of the cranes.
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The competency and qualifications of crane operators and lifting team were assessed by the contractors to ensure these key personnel possessed the necessary safety knowledge and skills to perform the intended tasks safely.
Monthly colour-coding system
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predetermined limit. A second alarm was also fitted externally, which would emit a loud audible alarm above the ambient site noise levels to draw attention should overloading conditions occur.
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Areas of Concern
Notwithstanding the above good practices, the auditor also observed some substandard practices and conditions such as:
Verification of lifting gears’ validity by project team
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All lifting zones at worksite were clearly demarcated and cordoned off. Warning signs were also displayed prominently.
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All Lifting Machines should have its SWL and LM number clearly marked on its body. However, the exercise revealed that one of the cranes did not comply with this requirement.
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One crane was found with an illegible boom angle indicator.
Demarcation and warning signs in place whenever cranes are used
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All load charts were translated into English and prominently displayed inside the crane’s cabin. All the operators were able to demonstrate that they understood the contents of the translated charts.
Illegible boom angle indicator
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At one of the sites, the lifting plan, which monitored the numbers and movements of cranes used, was not updated.
These audit findings were promptly highlighted to our contractors for their corrective actions.
Continuous efforts in conducting the thematic exercises have been well received by LTA project teams as well as contractors to arrest any deficiencies and share the lessons learnt. By and by, many of our contractors have initiated similar exercises on their own accord. LTA is confident that such exercises/ efforts can help to achieve a higher level of safety for the construction industry in Safe Lifting Operations.
Externally fitted visual/audible alarms
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>>
Conclusion
Audible and visual warning devices were installed on all cranes. Such devices can provide ample warning to the operator should the Safe Working Load (SWL) is near its
by Tan Jway Kwee Safety & Health (Enforcement) Manager Safety Division
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Creating Safer Work Zones Providing Good Visibility When driving through work zones, motorists would experience a series of deviation from the usual route that they take, these include narrow lanes, traffic merging, regulated speed, work vehicles entering the traffic flow and other disruptions. LTA has a Code of Practice – Traffic Control at Work Zones and contractors are required to submit a Temporary Traffic Control Safety Submission when they intend to carry out road works over a long period of time. The approved traffic plans are implemented at the work zones. One key point in this traffic plan is the provision of ‘Stopping Sight Distance (SSD)’, so that motorists can see well in advance, react to the changes and travel safely over these areas.
➢ ➢ ➢
Increasing the radius of the realigned road to meet the SSD requirements. Setting back the obstruction away from the curved section to increase visibility round the bend. Reducing the speed limit to no less than 20km/h below the original speed limit.
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4
>> What is SSD? Construction vehicles entering and leaving are commonly encountered by motorists at work zones. The positioning of the access/egress to the work site must be carefully studied in order to allow construction vehicles to easily maneuver and give motorists sufficient time to react. Deceleration/acceleration lanes with appropriate distance should be provided for roads with higher speed limit to enable construction vehicles to enter and leave the worksites safely. It is also important that construction vehicles have good view of footpath fronting the worksite egress points. Traffic controller should be stationed at these locations to regulate the movement of construction vehicles to ensure safety of pedestrians.
In the following sections, we will highlight some of the common areas/locations within a work zone that have presented SSD concerns to road users.
>> Pedestrian Crossing Areas It is important that motorists have a good view on the movement of traffic and pedestrians waiting at crossing points of junctions. Pedestrians should also be given a good line of sight of the approaching traffic so that they can gauge and determine the gap in traffic to cross the road safely. Road Designers/Traffic Engineers should be mindful of the needs of road users in different road environments. For example, at crossing points near schools, motorists view should not be obstructed; SSD is important here as young children’s height is shorter as compared to an adult. All obstructions should be removed, relocated or even lowered to create good visibility.
4
8
Relocated Bus stops
>>
Bus stops should be located on the straight section of the road as far as possible. Such arrangement would enable bus drivers to have a clearer view of the bus bay and allow motorists to notice their presence at the bus stops. It is also important to provide bus drivers with a good view of approaching traffic so that they can gauge traffic gaps and join the traffic stream safely.
4
>> Curved Sections of Realigned Road Landscaping, street furniture, hoardings and construction equipment located along the inner side of a road bend or on the central median can significantly reduce motorists’ view of the traffic conditions ahead. Motorists could be caught off guard when they drove round the obstructed road bend and encountered traffic queues, dropped objects on the road surface, pedestrians or closure of traffic lanes. These could lead to traffic accidents as the motorists have less response time. Possible solutions to overcome SSD at realigned roads include:
Conclusion
>>
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Location of Work Access
Stopping Sight Distance or Good Sight Line is defined as “the length of roadway visible to motorists and the distance ahead for motorists to anticipate, stop and avoid potential collisions.” The distance to be provided is dependent on the design speed to be adopted for the temporary traffic control scheme.
Providing SSD is essential in helping road users to move safely through work zones. Therefore, it is important to check these concerns at these critical areas, and take proactive steps to improve road safety for all road users. by Alvin Soong Road System Safety Manager Safety Division
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‘ No Flood, No Silt’ Friends of Water
>> PUB’s Friends of Water Programme Aldo Leopold once said in the Sand County Almanac, ‘The life of every river sings its own song, but in most the song is long marred by the discords of misuse.’ Perhaps the most relevant case of how our waterways can be misused is the discharge of excessive silt from construction sites into our canals due to ineffective earth control measures (ECM). The PUB faces an insurmountable challenge in leading the nation to keep our water sources clean and sustainable for our people and future generations. Hence, the Friends of Water Program was launched to collaborate with the 3Ps (Public, Private and People) sectors to meet this challenge. LTA is proud to be a family member of this program.
>> LTA Becoming Friends of Water
Provision of adequate sedimentation tanks
The Friends of Water recognition is conferred for the earth control framework that LTA had established for its worksites. LTA has adopted 3Es (Education, Engineering and Enforcement) approach in assisting and ensuring its contractors meet the discharge threshold of 50 mg/l of Total Suspended Solid (TSS). As Friends of Water, LTA will continue with all its effort to strive for 100% full compliance on Earth Control Measures at its worksites. In this article, we will highlight some of the findings from inspections by LTA’s Environmental Engineers that will assist contractors in meeting the target.
Last but not least, effective earth control requires constant maintenance and review. Constant maintenance is required to ensure that containment system such as sedimentation tanks and silt fence are always in good condition. Investigation and corrective action will have to be carried out to evaluate non-conformance and the effectiveness of the system. There is also a need to train and raise awareness among sub contractors and workers on the requirement of earth control measures in order to monitor the system. One of the areas that can be trained is learning to identify 50 mg/l of TSS through the colour comparison chart.
>> Best Earth Control Practices at Sites Effective erosion control at source is the most important and primary measure to tackle silty discharge at worksites. Emphasising this, LTA has been working closely with its contractors to ensure works are well planned to minimise pre-mature land clearing and exposing of bare earth surfaces. Control measures such as turfing, paving and the use of erosion control blankets are introduced at active worksites to mitigate silty discharge.
4 Conclusion
Minimisation of Bare Soil Surface
>>
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Colour Comparison for Silt Content
The target of ‘No Flood and No Silt’ is a challenge that the construction industry strives to meet. As an infrastructure developer, LTA has allocated financial resources in contractual requirement for the implementation of ECM, provided advice and direction to our contractors. ‘No flood, No Silt’ is an ambitious target that LTA strives to meet and can only be attained when we have a group of committed team; consisting of contractors, sub-contractors and workers, with a rigorous mind and selfless heart for making each drop of water count.
The second emphasis is the provision of adequate sediment control.The addendum of the revised Code of Practice on Surface Water Drainage (August 2006) had stipulated the need for a treatment system with a storage capacity to cope with the volume of water from a rain based on a minimum design return period of 1 in 2 years storm. Therefore, contractors must ensure that this requirement is met through the assistance of QECP (Qualified Erosion Control Professional) during design and throughout the construction phases.
by Tai Jo Fen Environmental Engineer Safety Division
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Control of Bored Piling Noise at LTA Project Sites
>> Introduction In April this year, Safety Division’s Quest team, Hard Hats, successfully clinched a Star Award for LTA in the National IQC Convention. Every year, only the top 1% of the nation-wide entries can be conferred the Star Award. Safety Division is one of the four teams to clinch this award since 2003, and the team will be in Beijing later this year to present their project at the International Convention on Quality Control Circles (ICQCC).
Kelly bar
A bored piling rig with bored soil prior to the ‘spin and lock’ process
Currently, most of LTA’s projects that are near to residential or noise sensitive buildings are lined with noise barriers along its perimeter site hoardings. However, these noise barriers are not able to specifically target any particular noisy machine. Hence, a more specific form of measure must be developed to address this area.
Hard Hats’ leader, Matt Chew, receiving the 2007 Star Award trophy from Mrs Rosina Howe, LTA’s Group Director for Innovation & InfoComm Technology.
>> Background Safety Division’s winning project “To Improve on Noise Mitigation Measures on Construction Sites” looked at the control of noise during bored piling operation in a bid to improve the working environment for our staff as well as a better living environment for the adjacent residents.
Based on the concept of addressing noise at source, the team set out to study bored piling rigs at work. The rig operators were told to spin and abruptly halt the Kelly bar at different heights and the noise generated was recorded. It was noted that the noise produced by the reverberation through the Kelly bar was significantly lower in comparison to the loud undesirable noise produced at the rotary head.
Mitigating Measures on the Rotary Head
>>
This is especially relevant in today’s context as it is no longer sufficient to keep our noise emission levels within the allowable legislative limits. There is a growing demand for better quality of life and this means that the industry has to continuously improve the way it carries out its work in order to satisfy public expectations.
After much research and study, the team started to work on designing a noise bracket to enclose the rotary head. A prototype was built and an in-house test was conducted.
>> Identifying the Source Hard Hats conducted surveys among LTA project teams and garnered feedback from the public, narrowing down bored piling noise as the main source of disturbance during the day. This form of noise is created when the Kelly bar of a bored piling rig is brought to an abrupt halt. This ‘spin and lock’ of the Kelly bar creates an inertia to dislodge the bored soil from the auger. Unfortunately, this sudden brake is only possible by forcefully locking the spinning Kelly bar in place at the rotary head. This abrupt halt creates excessive noise in the region of 100dB at source, and the entire soil dislodging process will repeat itself every two to five minutes until the desired depth is reached. This form of intermittent, high pitched noise is the most irritable noise source perceived by the receiver.
Testing of prototype noise bracket
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reduction in peak noise brought about a consistent noise output which could lessen the disturbance on the receiver.
Benefits of our Project
>>
As expected, there was not much fluctuation in the readings as the test was carried out in a quiet enclosed room. The 3 highest peaks recorded before testing with the scaled-down model were: 60.9dB, 58.4dB and 54.3dB (dark blue line). The 3 highest peaks recorded using the scaled-down model were: 54.8dB, 54.7dB and 54.4dB which translated into an average reduction of 4dB. This means a 23% reduction in terms of perception.
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Cost savings due to the reduced manpower and time spent on investigating and follow-up of public feedback.
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Work may progress smoother with lesser intervention.
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Quieter environment for the public and site staff.
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Noise bracket being mounted on the rotary head can save land space and does not interfere with machine’s operations and efficiency.
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Enhances the image of LTA as a socially responsible organisation.
Lab Test Before & After Using Scaled-Down Model 65 Before using model
dB
60 55
After using model
50 45 1
3
5
7
9 11 13 15 17 19 21 23 25 27 29
Secs
Results of in-house test, measured using a Type 1 noise meter
Buoyed by the positive showing of the in-house test, the team proceeded to fabricate the actual noise bracket. Aluminium alloy was used for the main frame as it is light and easy to handle while polyester foam and polycarbonate were chosen for their acoustic properties. The final product was installed on the rotary head of a bored piling machine and results of the test conducted were illustrated below:
dB
Noise Readings Before & After Implementing Noise Shield
95
Without noise shield
85
With noise shield
Noise bracket mounted on the rotary head
75 65
Conclusion
Secs
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1 22 43 64 85 106 127 148 169 190 211 232 253 274 295
Although the project is by no means the solution for noise issues on construction sites, the team hopes to inspire the construction industry to approach and tackle environmental concerns through the use of innovative and feasible ideas to improve the quality of the environment for everyone.
Results of on-site test, measured using a Type 1 noise meter
The purple line indicated the noise level captured after installation of the noise shield. There were no obvious peaks and the noise output remained generally constant throughout the period of measurement. The 3 highest peaks recorded before implementation of the noise bracket were: 95.3dB, 93.9dB and 92.8dB, giving an average of 94dB. The highest peaks recorded after implementating the noise bracket were 91dB, 90.8dB and 90.4dB. Thus the average noise level after implementation of noise shield was 90.7dB. This translated into an approximate 4dB reduction which is equivalent to 23% reduction experienced at the receiver’s end in terms of perception. This
The team is looking at further enhancing the current design. Coupled with active public relation works, scheduling of works, other engineering techniques and greater awareness amongst staff and workers alike, construction noise can definitely be further reduced. by Matt, Chew Boon Bwan Environmental Engineer Safety Division
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Editorial Page Constructon Safety, Health and Security Campaign 2007 LTA Contract 856 is honoured to be chosen for the opening ceremony of ‘Construction Safety, Health and Security Campaign 2007’ on 04 May 2007.The Campaign is into its 24th year and LTA is a member of the organizing committee.
安全排第一 an quan pai di yi Safety Number One 一早欢欢喜喜上工地, yi zao huan huan xi xi shang gong di Every mor~ning happily go to work 一晚平平安安回家去. yi wan ping ping an an hui jia qu Every eve~ning safely return home 父母姐妹兄弟, 老婆和子女, fu mu jie mei xiong di, lao po he zi nÜ Every family mem~ber, the ones you love and care
Guest of Honour(second from left), Mr Hawazi Daipi, Senior Parlimentary Secretary for Manpower, with the VIPs signing their safety pledge.
LTA’s Safety Workshops LTA regularly conducts Safety Workshops for its staff to share the technical challenges and experiences faced during the safe delivery of their projects. It is also a useful platform for staff to learn from one another and for senior management to interact with the site Mr Tang Choon Siang from NEA speaking at our 17th staff. Guest speakers from Safety Workshop on 23rd July 2007 private organisations and government agencies are also occasionally being invited to share their expertise at these workshops.
MILLION ACCIDENT FREE MANHOURS
每天都等我们回去. mei tian dou deng wo men hui qu Every~day waiting for your return 有~爱的家是多么幸~福的, you ai de jia shi duo mo xing fu di Love and Care for them are what we’re living for 我们必要~去多珍惜 wo men bi yao qu duo zhen xi We must cherish~, value and treasure SAFETY, SAFETY, SAFETY必须要争取 Safety, Safety, Safety bi xu yao zheng qu Safety, Safety, Safety is to be strived for 安全排第一, 生命要爱惜, 你我是好Buddy an quan pai di yi, sheng ming yao ai xi, ni wo shi hao Buddy Safety number one, safety for everyone, we are all for safety.
Congratulations to our Contractors for achieving one million accident free man-hours for the period January-June 2007: ➢ ➢ ➢ ➢
Samsung Corporation, Contract 423 Kallang-Paya Lebar Expressway Taisei Corporation, Contract 424 Kallang-Paya Lebar Expressway Woh Hup – Shanghai Tunnel – Alpine Mayreder JV, Contract 855 Circle Line Stage 4 Sembawang Engineers and Constructors, Contract 856 Circle Line Stage 5
EDITORIAL COMMITTEE Advisor Corporate Safety Committee
Safety Ong says... “Do you know that overloading is one of the causes of crane accidents? What are the other causes?”
Editor Lee Ngee Hock, David Writers • Chew Boon Bwan, Matt • Tai Jo Fen • Lee Ngee Hock, David • Tan Hock Seng, Andrew • Soong Kheng Boon, Alvin • Tan Jway Kwee Circulation Officer Tan Chee Lang
Contributions or feedback to: Land Transport Authority, Safety Division 251 North Bridge Road, Singapore 179102 Tel: (65) 6332 6136 Fax:(65) 6332 6129 Email :
[email protected] Safety News is also available online at http://internet-stg.lta.gov.sg/Projects/index_proj_safety.htm
