This research report identifies the risks and hazards associated with scraper winch systems that can lead to potential accidents in the gold and platinum sector. To analyze accident records associated with scraper winch systems maintained in the SAMRASS database;
L ITERATURE REVIEW
The study aims to determine whether the scraper winch system is indeed a major risk to the gold and platinum sector and to identify whether further specific research is required on various aspects of the scraper winch systems.
A NALYSIS OF SAMRASS DATABASE
M INE AND SUPPLIER INTERVIEWS
R ISK A SSESSMENT
H UMAN F AILURE P OTENTIAL A SSESSMENT
An analysis of the SAMRASS database for the period 1988 to 2002 shows that traffic accounts for 22% of all accidents in underground gold mines and 25% of all accidents in platinum mines. Scraper-related accidents account for 23% of all traffic accidents in gold mines and 36% of all traffic accidents in platinum mines.
I NITIAL A NALYSIS
S CRAPER HAZARD DESCRIPTION
Another concern is the transportation of the scraper scoop, as workers are often injured while transporting the scoop. The data was further examined to determine the injured person's activity at the time of the accident.
A CTIVITY OF INJURED PERSON
Principal causes of accidents
A further analysis was performed to examine the main causes of scraper winch accidents from the SAMRASS database (1998 to 2002). From the two tables it is clear that the main causes are due to poor supervision, judgment and lack of adherence to safety procedures.
C URRENT P RACTICE ON S OUTH A FRICAN M INES
Findings from mine visits
Communication is initiated via the cap lamp to the photoreceptors on the device's surface. The DCP signal units include the game's locking system and communication to the game driver.
Findings from winch Supplier interviews
Accidents can be reduced or avoided by immediately stopping the winch if a dangerous situation arises. Winches have also been developed with a safety barrier, which protects the winch operator from injury due to contamination and rope entanglement.
G ENERIC H AZARDS
- Struck by winch
- Struck by ropes
- Struck by scraper scoop
- Struck by snatchblock
- Punctured by rope strands
- Entanglement
The winch operator stands in the same direction as the motor (the motor is perpendicular to the drum), which provides sufficient clearance from the drum and protects the operator from injury from the drum and rope entanglement. Being struck by a winch has been identified as a significant hazard, with the primary causes being falling and moving winches during their transport, installation, operation or removal. Being struck by ropes has been identified as a significant hazard for all stopworkers, with most accidents likely to result in serious injury or death.
Most accidents often happened when people were sitting, waiting, observing, monitoring or even sleeping (stationary positions) in wrong positions along the gorge or in the face of the stope. Being struck by a scraper scoop was identified as a significant hazard with accidents likely to occur in the clearance, along the gully or in the stope face. A snatch block is a heavy, solid piece of metal, and getting hit by one often results in serious injury or death.
A SSESSMENT OF C ONTROLS
- Scraper winches
- Snatchblocks
- Ropes
- General personnel safety
To minimize the risk of ropes catching loose clothing and pulling the operator into the winch drum, to prevent accidental contact with moving parts of the machine. Barricade – this is installed around the winch box to prevent accidental access to the winch box and possible contact with moving machinery. Interlock device – an interlock device prevents unauthorized use of a winch when repair or maintenance work needs to be carried out and when the winch is at a standstill.
Another observed type of lockout locks the winch locking device and a colored light bulb mounted in the winch housing illuminates, usually bright red or green, so that the light bulb turns on automatically whenever the winch is stationary and not locked. The lighting is intended to increase visibility in the winch housing and reduce the chance of accidents occurring there. Winding the rope into the drums - the usual procedure calls for the use of a snap block located in front of the winch when winding the rope into the drums.
Pre-use rope inspections – operators are expected to inspect ropes passing through blocks; cut off the worn or damaged parts of the rope and, if necessary, perform splicing; and cut off the protruding strands of rope. Operators tend to use the easiest way to splice ropes, regardless of the type of ropes to be spliced, to save time - tying the ropes in a figure eight knot; and the protruding strands of rope are rarely cut.
H UMAN F AILURE P OTENTIAL
Job factors
Many procedures focused only on what needed to be done, without identifying the dangers associated with taking shortcuts and not adhering to procedures and standards. In addition, there was no objective measure of rope life and limits of deterioration acceptable before rope replacement. Most operators complained about the lack of equipment for critical tasks such as moving winches and winding ropes into drums – chain blocks and clamp blocks respectively – leading to shortcuts and unsafe work practices;
Individual factors
Organisation and management factors
Regulations applicable to scraper systems are contained in Chapter 19 of the Minerals Act 1991. However, there is a need to refer or cross-reference other chapters of the Minerals Act in order to gain a full understanding of the legal requirements. This cross-referencing creates confusion and excuses for not meeting all the legal requirements;.
This is left to the person appointed under regulation 2.13.2 or the engineer, and explains the wide variation in mine standards and codes of practice. Appointing a person in accordance with regulation 2.13.2 to be responsible for machinery can cause confusion, resulting in overlapping areas of responsibility between the appointed person and the engineer, with neither of them knowing their responsibilities. However, the move to appointing "production engineers" or "horizontal transport managers" helps alleviate the problem.
Regulation 11.3.8, which governs this, can be interpreted as also applying to scraper winch systems; The provision in the standards or code of practice is left to the engineer or designee within the meaning of regulation 2.13.2.
A NALYSIS OF SAMRASS DATABASE
M INE AND S UPPLIER INTERVIEWS
R ISK A SSESSMENT
It is clear from the above that mines should conduct problem-oriented risk assessments of scraper winch systems, especially after major accidents or incidents, and that routine risk assessments should be incorporated into daily safety management. Some mines already do this, but in some locations no evidence could be found that risk assessments have ever been carried out on scraper winch systems. For a risk assessment-based approach to reducing accidents to be effective, the first requirement is that it is actually implemented.
The legal requirement for a risk assessment is that the findings of such an assessment must be widely communicated to all stakeholders involved to make them aware of the main risks they face in their workplaces. Work standards, procedures and training programs should then be based on the hazards identified through risk assessments. An "appropriate and sufficient" risk assessment is primarily determined by the quality and appropriateness of the risk identification and risk control process used.
The documented example of the risk assessment facilitated by the project, given in Annexes 2 – 4, illustrates the methodology to be followed and the level of detail likely to be required in a risk assessment to identify the significant hazards that currently exist, effectively address. The documented example can be used by mines as a reference to ensure that significant potential hazards and relevant controls associated with the design, installation and operation of scraper winch systems are not overlooked by mine risk assessment teams.
S IGNIFICANT G ENERIC H AZARDS
Rules and Standard Procedures: In many cases, mines had produced generic procedures to cover all their business units or shafts, but due to differences across scraper winch system installations, these were either impractical or too general to be of value on individual installations. To be fully effective and encourage high levels of compliance, rules and procedures must be both practical and relevant to the operation they are designed to handle. Generic procedures and guidelines across all business units, mines or shafts can be a good starting point, but they need to be checked against each of the operations they are designed to apply to and amended where necessary.
Training: Once such effective standard procedures are developed, they must be effectively communicated through training to the appropriate members of the workforce. For such training to be effective, participants should not only be instructed in the procedures to be followed, but should also be made aware of the potential hazards and risks that these procedures are intended to mitigate and the risk that are faced if these procedures are not followed. used in practice. When training for multiple business units, mines or shafts, training programs must follow the rules and standard procedures of the various operations.
The effectiveness of the present system, which includes a bell wire connected to a signaling device (air whistle or bulb), is usually affected by several factors, as noted elsewhere in this report. Improved communications are considered to be one of the areas that can make a significant contribution to the improved safety of scraper winch systems.
R EGULATIONS REVIEW
S UMMARY
What major problems have you experienced with scraper winch systems over the past five years? Have you done any risk assessment on scraper winch systems and what were the findings of such an assessment. The risk assessment process is designed to examine scraper systems in gold and platinum underground mines.
The risk assessment team identified the hazards by examining each task and activity related to the scraper winch systems at the above locations and using their own experience with the system in question. Winches not always locked Locking procedures impractical Inefficient/deficient locks Supervision not always present. Untrained or inexperienced Winches not always locked Locking procedures impractical Inefficient/deficient locks Supervision not always present.
Damaged and ineffective Not always installed Often not replaced after maintenance work Inadequate control Not always installed Damaged and ineffective Often not replaced after maintenance work Inadequate control. Separate driving lanes are not always provided or are obstructed. The winch started up without warning. The start-up process is inefficient in long chutes. Inexperienced or inexperienced. The inspection is not always done. No monitoring or control. Inexperienced or inexperienced. Unsupervised.
Rigging not always tailor-made Untrained or inexperienced Guidance not always available Spare parts not immediately available.
