Dump truck overturned at Okke plant quarry 1
DUMP TRUCK(35TON) OVERTURNED AT OKKE PLANT QUARRY
12th May 2010, 10.15 amContractor – Joongang co.
2
Title Descriptions
i) Incident Description
ii) Profile of Victim
iii) Immediate action
iv) RCA
- Team
- Chain of Event
- Sequence of Action
- Relevant Photos
- Root Cause Analysis (RCA)
- Main causes of the Incident
- System and Management Related Causes
v) Corrective and Preventive Action
vi) Key Learning Lesson
Dump truck overturned at Okke plant quarry 3
Date and Time of Incident : 12th May 2010, 10:15 a.m.
Person involved : (51 years)
for the past 10 years as a dump truck operator
Company :
Type of injury sustained : Crack of two ribs (Injured worker is stable as
reported after medical check at Gangneung Asan Hospital)
Incident Description : At 10:15 am, Dump truck(No.1222) was overturned
at the limestone stock pile because the crest of stock pile was collapsed.
Based on the interview, dump truck reached crest of stock pile to dump the
limestone as backward.
The dump truck was slid and overturned when the operator was about to
dump limestone at the crest of stock pile.
Incident Description
4
Profile of Victim
Victim Name : ************ Position : Dump Truck Operator Age : 51 years old Family Situation : Married and 2 children Year of Experience at ******* : 10 Years Driving License Category: 1st grade certificate for heavy truck
Work Location Quarry 2 Centre
Work Activities Transporting limestone to stock piles
Type of Injury The injured worker had crack of 2 ribs after medical check up and came back to his work now.
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Immediate Actions by Plant Team
No.No. Corrective ActionsCorrective Actions Action PartyAction Party Time Time lineline
1 - Stop all stock pile work
Industrial Director
&Plant
Management Team
12thMay
2 - Sharing accident information to all teams
3
- Inspection of the condition of 9 stock piles located in quarry site and improved stockpiling method : “Preferred” Stockpiling : 2 → 7 “Secondary” Stockpiling : 3 → 2 (Discussed with ATC : we have determined what is the status and possible action for the remaining 2 stockpiles where "secondary dumping method" is applied) “Prohibited” Stockpiling : 4 → 0
4
- Conference call with regional safety coordinator and ATC : Further investigation by technical point of view, develop communication material for the other BU to avoid any recurrence
Dump truck overturned at Okke plant quarry 6
Root Cause Analysis
No.No. NameName DesignationDesignation
1 JongGoo Moon Industrial Director
2 SungRae Chung Plant Operations Manager
3 SeYong Lee Production Manager
4 WeonGyoo Kim Mining Team Leader
5 KwanKyo Chung Mining Team Engineer
6 JunYong Pyun Mining Team Engineer
7 YongIn Woo Contractor - Joongang Co.
8 DongGun Park Contractor (foreman) - Joongang Co.
9 WonWai Kim Contractor - YeGun Co.
10 SangWoong Lee Contractor - DaeLim Co
11 TaeHun Kim Contractor - SooKwang Co.
12 SooChang Kim Plant Health & Safety Coordinator
RCA Team
7
Chain of Event (Before the Incident)
Time Activity
08:10 am The injured worker conducted visual inspection of dump truck before operating
08:30 am The injured worker drove first load to the stock pile from bench(B-0) at quarry 2 central
10:14 am Dump truck reached the stock pile to dump 8th limestone transporting
10:15 am Dump truck reached the crest of stock pile as backward and was about to dump
10:15 amDump truck was slid and overturned at the crest of stock pile when the operator was about to dump limestone due to collapse of the crest(Stockpile height : 10m)
10:15-11:20 am
The accident was witnessed by inspector (Mining manager) and the driver rescued by contractor’s foreman (DongGeun Park). Then transferred to the hospital by 119 (Emergency Ambulance) at 10:40 a.m. The truck driver arrived at the hospital at 11:20 a.m. - Mining manager and Foreman : First Aid trained - 119 : Korean rescue staffs by government (Branch office is located in Okke)
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Sequence of Action Before Accident - Sketch
B-0 Working place
Transporting limestone
The operator reached the crest of stock pile as backward and was about to dump limestone but the crest of stock pile was collapsed and dump tuck was overturned.
Along the Hauling Road Dump truck was Overturned
Limestone loading by excavator
B-0 Working Place
Accident Area
Point 1
Level 1 Point 2
Point 3
Level 2
350 m
Limestone was loadedby excavator
Transporting limestone
The operator reached thecrest of stock pile asbackward and was about tobegin to dump limestone
The material has been taken at the bottom on May 11th .
Dump truck overturned at Okke plant quarry 9
Photos
Safety berm
backward
Berming 10M
Sliding and overturned
Dump truck overturned at Okke plant quarry 10
Photos
Dump truck overturned at Okke plant quarry 11
Photos
Dump truck overturned at Okke plant quarry 12
Photos
Safety Berm gave away
truck moving backward
Dump truck overturned at Okke plant quarry 13
Accident Figure at Limestone Stock Yard
Safety Berm
Sliding and overturned
Dump truck overturned at Okke plant quarry 14
Root Cause Analysis
RCA FILE
• The daily inspection of the dump truck was conducted by operator before
starting the work including breaking system and there was no defects
found.
The regular preventive and specific inspection was conducted by
maintenance workshop in quarry.
• The dump truck has safety facilities like rear camera, frontal mirror,
reversing alarm and seat belt.
• The condition of operator was in normal.
• The operator was fasten seat belt.
< Vehicle Inspection and operator’s condition >
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Root Cause Analysis
Dump truckoverturned
Crest collapseWeak dumping
area andunstable slope
Material taken atthe toe
Fine materialpiled on theupper slide
Wet and untightslope due toprevious rain
Weight of dumptruck
approx.52t
Direct dumpingat the crest
Misunderstood ofdumping method
in advisory Cause2 Mistranslation
Immoderatebackward
Witness
Lack of riskawareness about
change ofworking
environment
Cause3Insufficient
training of riskmanagement
The weightturned to one
sideWitness
Lack of riskObservation/
Assessment inreal time
Cause4Lack of risk
assessment skill
Insufficienttraining of riskmanagement
Dump truckfailure
Daily work logInadequate
SOP Cause5
Not fullyunderstandingof Advisory
Cause 1, physical conditionof the stockpile
<System &Management
related causes><Behavior related cause>
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Main cause of the Incident (Based on the RCA)
Misunderstanding of working method : Main cause of the incident is misunderstanding of "where " with "when"
According to stock pile advisory,
“Secondary” Method of Stockpiling involves dumping a load directly over the crest of the pile. For this method to be performed safely, adequate berms must be maintained ~ ….
It is critical to ensure that material is not removed from the toe of the pile when dumping is taking place at the top of the pile. → Applied
“Prohibited” Method of Stockpiling involves ~ …. ~
where material has been removed from the toe is prohibited. → Not applied
Root Cause Analysis
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System and Management Related Causes
Lack of risk assessment : Risk assessment of dumping work did not make
complex working condition which clearly identifies all potential & practical
risks (for example, multiple visible inspection for stable repose angle from
the pile upside and downside)
Lack of real time inspection system : Real time inspection needs to check
the risks of working condition and unsafe behavior depending on the
working environment and weather condition
Inadequate SOP : SOP of dumping work is in place but there is inaccurate
application for dumping work due to misunderstanding of stock pile
advisory
Insufficient communication : Lack of communication between inspector
and dump truck operators about the risks observed by inspector
Root Cause Analysis
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Behavior related causes
Mistranslation of the Advisory : Stock piling methods are not correctly translated to cause incorrect application of stock piling method.
Insufficient training of risk management : Workers are not skillful of risk recognition and assessment because of insufficient training of risk management including refresher training.
Not fully understanding of the Advisory : Especially stock piling method is not fully understood by workers even though repetitive training due to the mistranslation.
Root Cause Analysis
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Good/ Positive Risks / Issues
• Experienced 10 years
• Safety training – MEA, Stock & Surge pile, Standard & Advisory, etc.
• Emergency Evacuation : quick
• Protection canopy of the truck
• Seat belt
• Camera installed in the rear
• Vehicle – good condition
• Inspection, shift check
• No alcohol, Day worker, Looked okay
• No overloading (35 ton)
• Reconsider the remaining 2 stock piles method – under review
• Need front-end loaders – if we want preferred stock piles method
• Location of truck at crest & toe (2m – 10m)
• Flexible movement of the dump point & Stock pile & crest (3 or 4 times within 6 months/ 2-3-5-8m)
• Rain-wet material impacted compact
• Incorrect method used prohibited – understanding (how come for years happening?)
• Risk assessment – awareness on changing environment & situation / supervision & real time
• communication – joint assessment of risk
Root Cause Analysis
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Risks Safety Measures
Fog/Snow/Rain _ situation change
Frequent monitoring by supervisor in real time and sharing information of working condition
Floating rocksManagers conduct specific inspection of bench face considering climate change more frequently while raining or snowing (install buffer zone or isolate the risky area)
Flying rocks Changing current blasting direction to safety area where no risk zone from blasting when drilling work
Communication processEstablish robust communication system to share all risk situation in real time using radio.
Road condition (Gradient/Width)
Gradually improve the gradient and width of the roads
Falling risk of equipment _ side berm
Install strong side berm
Other risks in Quarry
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Corrective and Preventive Action (Immediate)
No Corrective Action By Whom By When Status
1 Stop all stock piling work Plant Mgr. Immediate Done
2 Sharing accident information to all teams and Regional H&S director and Relation director.
Industrial Director Immediate Done
3
Inspection of stock pile condition (stopped 4 activities on prohibited stock piling and changed 1 activity from secondary methods to preferred stock piling).According to the inspection of all berms for road side, condition was good.
Industrial Dir.Plant Mgr.
WG KimImmediate Done
4Conference call with regional safety director & relation director. Technical support was coordinated by ATC geo-mining manager.
Industrial Director
Immediate Done
5 Removed unstable steep slope of the accident stock pile. YongIn Woo 13-5-2010 Done
6 Training of the revised Stock Piling method was conducted to all workers in quarry.
Contractors 13-5-2010 Done
7
Safety inspection of all working areas in quarry and immediate actions for improvement were taken until May 14th, such as ;· Installation of buffer zone at Q2T· Expanded entrance road at Q2T development area· Removed floating rocks at Q2C· Expanded transporting road at Q2C
WG KimContractors 14-5-2010 Done
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Corrective and Preventive Action (For Improvement)
No Corrective Action By Whom By When Status
1Develop risk assessment of dumping work which clearly identifies all potential & practical risks under support of ATC geo-mining manager.
ContractorsJY Pyun 20-5-2010
On-going
2
Effective inspection system should be established with a series of visits at suitably frequent intervals to ensure that work activities are monitored and that any unsafe acts and conditions are observed and corrected
ContractorsJY Pyun Done Done
3Improve communication between inspector and dump truck operator about risks observed in real time
ContractorsKK Chung 25-5-2010 Done
4
Revise standard & FHRA of dumping work and training (revision of SOP)
- Material should be pushed by loader or dozer to the crest of stock pile where material is removed from the toe.
- If dozer or loader can’t operate, prohibit the dumping directly. Otherwise dumping work should be done at the toe of stock pile
ContractorsWG Kim 24-5-2010 Done
5Training of risk management skills and stock pile advisory in detail to make sure all contractors fully understanding
ContractorsJY Pyun 31-5-2010 Done
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Key Lessons Learned
Workers should clearly understand Standard and Advisory (e.g.If you take materials at the toe of the pile direct dumping is strictly prohibited)
In order to set up a SOP, it should be based on the Group Safety Standard & Advisory fully understood by workers.
The risk management system including inspection, risk assessment and communication system should be working effectively on-site to control not only formal & visible risk but all potential & practical risks in real time and regular monitoring should be followed to make sure the system is working
All employees and non-employees that operate or ride in any mobile equipment or vehicle shall fasten seat belts at all times.