risk to operator & pedestrians using lhd canopies in low mining … · 2018. 3. 13. ·...

Risk to operator & pedestrians using LHD canopies in low

mining heights

Paul van der WaltResident Engineer

Murray & Roberts CementationKroondal Platinum Mine

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ContentsContents

OverviewEquipment Used Background HistoryDesign and purpose of LHD and LPDR CanopiesSequence of EventsRisk AssessmentOutcome of Investigations Other Options InvestigatedOther concernsLoss of Vision Conclusions

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OverviewOverview

Kroondal Platinum mine is owned by Aquarius (S.A.)The mine is situated 12km to the East of Rustenburg where the UG2 Platinum reef band is minedMurray & Roberts Cementation has carried out toll mining operations on behalf of the client since 1999

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OverviewOverview

Mining was initially conducted in the Kroondal mining lease area and, in 2004, a pooling and sharing agreement between Anglo Platinum and Aquarius commencedThis arrangement has increased mine life to be extended throughout additional ground as well as higher tonnages to be minedAt present, Kroondal consists of Central, East, 3 Shaft and 4 ShaftCurrent ROM tons planned at approximate 600,000 tons per month

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OverviewOverview

Current developments: – Mining of Sub-declines

at Central and East shafts– Sinking of declines at 3 Shaft

and 4 Shaft

Current life of mine is estimated at 15 years with further feasibility studies being conducted in order to extend life of mine

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Equipment in useEquipment in use

71 LHD’s are used to take ore from the panel and decline faces to the tips on the strike conveyor belts

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8 Aardmaster Hydraulic Low Profile Drill Rigs are used in the drill rig sections Hand held machines are used in the ledging and sinking sectionsRemote manual support rigs are being used for the blasting of slots for tip areas & support holes (Autorock Systems)Aardmaster Hydraulic Low Profile Drill Rig

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Other vehicles include 12 Utility vehicles and LDVsKroondal has ± 50km of 1050mm conveyor belt equipped with weightometers

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Background HistoryBackground History

Due to the low mining height, LHD’s and LPDR’s were not fitted with canopies following a risk assessment that was conducted at Kroondal during the initiation of the mine (1999)

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An incident, which resulted in a fatality occurred during November 2004 which involved an LHD operator who was operating an LHD without a canopy

This operator sustained a serious head injury which was, during the initial investigation, thought to have been sustained because of a lack of protection which could have been supplied by means of a canopy

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Fitment of canopies was re-visited. Numerous challenges were encountered due to the low mining height and associated infrastructure

An Issue Based Risk Assessment, involving the DME and IRCA, was conducted in order to obtain a safe and user friendly canopy on all the LHD vehicles at the mine following a Fault and Event Tree Analysis Program

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Design and purpose of LHD and LPD canopies

Design and purpose of LHD and LPD canopies

The accident initiated the thought of installing canopies onto LHD vehicles with the primary objective to mitigate risk of injury to the LHD OperatorsThe two areas of concern were the fall of object protection system (FOPS) and the roll over protection system (ROPS)– FOPS: is a system where the LHD operator is protected

from falling objects which includes falls of ground– ROPS: is a system where if a vehicle is rolled over, the

operator will be protected

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Due to the fatality the immediate response was that the installation of canopies on LHD vehicles had to be re-assessedA standard canopy was fitted to an LHD

Sequence of EventsSequence of Events

LHD with no canopy LHD fitted with a canopy

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The risk assessment team accompanied the vehicle underground but failed to progress because of the narrow mining heightsThe whole mine was surveyed to ascertain where the narrow mining heights were only to discover that there were no areas suitable for entering with a LHD fitted with a canopy

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Subsequently, the canopy was lowered from 1,8m to 1,57m highThis posed the problems that the driver’s vision would only have 25% clear vision around him; increasing risk to pedestriansEven on the maiden trip of the test LHD there were two incidents involving other vehicles which were prevented by the risk assessment team and not the driver

LHD with a 1.8m canopy

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The operator’s cab was then extended outwards some 300mm with the view that it would improve the operator’s visionThis innovation did improve his vision, but only on the side of the operatorDue to the canopy protruding it constantly struck the sidewalls as the operator was not used to the extended cabThe vision of the operator to the front opposite side and the back was still a major concern

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300mm

The operator had to physically climb out of the cab to see a vehicle approaching him from the other side

Operator’s cab was extended 300mm beyond the front wheel

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Risk AssessmentRisk Assessment

An additional risk assessment, to evaluate the advantages and disadvantages of the canopies was done involving IRCA facilitators using the Fault and Event Tree Analysis

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Outcome of Investigations:Risk of Fatality per LHD operation

Outcome of Investigations:Risk of Fatality per LHD operation

Without CanopyWith Canopy

Conclusion of the Fault Tree Analysis

Ris

k of

Fat

ality

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Fault Tree AnalysisFault Tree Analysis

Conclusion of the Fault Tree Analysis:The use of a canopy on an LHD may increase the risk of fatalityAlthough the canopy will reduce the risk of fatality in the event of fall of ground, the risk of fatality is increased in other areas due to reduced vision of the driverThere is little that differentiates the identified functions of an LHD. This is an indication that no major difference is introduced in the risk profile between the two options

From the Analysis it was proved that there is an estimated increase of 40% in the risk of fatalities

using an LHD with a canopy

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Other Remedial Measures Considered

Other Remedial Measures Considered

Flashing lights were installed (green on operator side, with red opposite) to increase pedestrian awarenessWe are currently investigating the possibility of installing proximity detectors in cap lamps to make the LHD operators aware of pedestrians which are in close proximity. The concern is that drivers will become complacentDevelopment towards remotely operated machines, is being pursued

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Other Options Investigated: Roll Bars

Other Options Investigated: Roll Bars

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Other ConcernsOther Concerns

Other concerns that arose were:Safety: The operator could not wear his hard hat and sit under the canopyErgonomics: Taller & larger operators could not sit comfortably within the cab adding to the hazards to the operator’s healthVisits to other mines were initiated and it exposed the same fact that the driver’s vision was severely obscured when utilizing a canopy

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Loss of Vision: Line of SightLoss of Vision: Line of Sight

The fact that the operator,with the canopy in place,has limited vision, theonus is on pedestrians toensure that they keep clearof moving machineryWhistles were issued to all underground employees as a compulsory part of PPE and operators were made aware that when a whistle blew they were to immediately stopThe fact that the pedestrian was now solely responsible for his own safety around LHD vehicles was concerning

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Loss of Vision: Line of SightLoss of Vision: Line of Sight

Operatorline of sight

This line of sight is below the top elevation of the LHD

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View of driver from driver’s cab with 300mm built out & canopy directly in

line with driver – 0°

View of driver from driver’s cab with 300mm built out & canopy directly in

line with driver – 0°

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View towards to opposite side of LHD (directly across driver) – 90° View towards to opposite side of LHD (directly across driver) – 90°

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View towards right back corner – 120°

View towards right back corner – 120°

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ConclusionConclusion

– The fatality rate increases dramatically by 40% because of the vulnerability of the pedestrians

– There is also the influence of the ergonomics by the canopy which may result in injuries and possible fatigue of the driver in a shorter period of time, which was not considered in the risk assessment

– It can be concluded from the results that the use of a canopy on an LHD will not reduce the risk of fatality although it lowers the risk of injury to the operator, the risk involving pedestrians are increased

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ConclusionConclusion

It can be concluded from the results of the risk assessments that the use of a canopy will not contribute to a safer working environment

LHD with no canopy LHD fitted with a canopy

Thank you

Questions?

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Underground operations commenced at Kroondal Platinum Mine in 1999At this time risk assessment highlighted no need for canopies, due to the low mining heightNo incidents demanding the utilization of canopies occurred at Kroondal Platinum Mine until November 2004

risk to operator & pedestrians using lhd canopies in low mining … · 2018. 3. 13. ·...

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