Incident reports raise awareness of risk trends, equipment, procedures and corrective actions. These three incidents were reported by Buildsafe SA.
An electrocution at a distribution board (DB) in a mine
The deceased electrician, another electrician and an electrical assistant were instructed to conduct a three-monthly earth leakage test on the low tension side (525 Volts) of an underground mini-substations on level 113.
The deceased was the scribe and recorded readings taken during the testing. He therefore did not wear the personal protective equipment (PPE) required by the mine procedure when testing is to be conducted on live electrical equipment.
The other electrician was wearing the required PPE, as he was conducting the physical tests on the live apparatuses.
During the tests, the deceased went alone to open the isolator switch panel, which feeds directly from the transformer. Although the isolator was switch off, the top connectors of the isolator were still live.
It is assumed that he wanted to conduct a visual inspection for hot connections on the terminals. The other electrician applied resuscitation while the assistant called for assistance. The paramedics arrived at the scene and took over the resuscitation to no avail.
Incident reports should include a description as above, causes, corrective steps, and relevant laws, regulations, standards or work procedures. Causes in this incident included;
• Indequate management controls.
• Inadequate risk assessment.
• Insufficient training, instruction and supervision.
• Worker complacency.
Corrective steps included;
• Review of risk assessment, operating procedures and systems of work.
• When tests are to be conducted on live apparatus or any live electrical equipment, all employees involved must wear the required PPE while present.
• When testing is not required in an electrical cubicle, the panel should be kept closed for the duration of the test, and no inspections should be conducted on any electrical cubicle before the power is isolated.
• Employees must adhere to operating procedures.
A crane jib strike, investigation and response
A crane’s fly jib struck a section of scaffolding causing minor damage to the scaffold and fly jib. The collision also temporarily affected electrical components on the fly jib.
The Job was stopped and the scaffolding was immediately red-tagged. The area was barricaded off and employees placed at two ends of the barricaded area to prevent workers from entering.
A third party was called to do a preliminary investigation. Production was notified of the incident.
After investigating the incident it was found that not securing the ball hook was the root cause. Usually the ball is secured but on this occasion “no sling was used to secure the ball hook”.
Also, the risk had changed by adding stinger, but was not reflected in the risk assessment. The risk assessment did not address travelling. The work procedure and daily toolbox talk will be updated.
Corrective and preventative actions taken included;
• Drafted an update procedure for tying of the ball hook (using supplier manual information).
• The work procedure and risk assessment procedure were revised.
• Communicated the revised document and distribute to service providers.
• Ball-hook to be hooked onto crane and only released when work commences, not while travelling to the work area.
• Communicate the incident to all divisions.
• Crane operator to be accompanied by flagman at all times.
A crane boom collapse
A crane boom collapsed while transferring concrete slabs from ground level to the roof of an administration building. While lifting concrete precast slabs of “unknown weight” using a mobile crane, the crane boom failed.
CAUSES OF EVENT;
• Lifting overload without assessing the weight and the associated risks.
• Lack of planning – Lifting study not conducted prior to lifting (Part of Daily Safety Task Assignment)
• Lack of effective supervision
• Lack of training – Not following rules/procedures
• Poor communication (Language barrier?)
• Lack of concentration by all relevant personnel, including riggers, crane operator and tag line controller.
• Proper planning to be done prior to any lifting activity – Identify the hazards and assess the risks prior toassigning workers for any activities.
• Qualified and competent supervisor to be assigned for all construction work, especially when dealing withcritical lifting and working at height.
• Refresher training for operator especially on ability to read load charts and on work procedures.
• Only trained workers should be assigned to lifting tasks.
• Proper communication to be made between Crane Operator and Rigger during any lifting operation.
• Ensure adequate awareness by toolbox talks with all involved in lifting activity and ensure their capability to handle the required task.
• OHS Act Sections 8 and 13
• Driven Machinery Regulation 18; Lifting machines and lifting tackle. No user should make use of the crane unless; (1)(b) it inconspicuously and clearly marked with the maximum mass load which it is designed to carry with safety: When this mass load varies with the conditions of use a table showing the maximum mass load with respect to every variable condition must be posted up by the user in a conspicuous place easily visible to the operator (9) No user may use a jib-crane with a lifting capacity of5 000 kg or more at minimum jib radius, unless it is provided with (a) a load indicator that does not require manual adjustment, from application of a load or, (b) a limiting device which will automatically arrest the driving effort whenever the load being lifted is greater than the rated mass load of the jib-crane, at that particular radius. (11) The user shall ensure that every lifting machine is operated by an operator specifically trained for a particular type of lifting machine.
• Construction Regulation 6; Competent supervision
• Construction Regulation 7; Risk Assessments.
Sources; Buildsafe SA
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