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Prosecution Details

Offender Baker Hughes Australia Pty Ltd (ACN 004 752 050)

Charges

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Charge Charge Number Offence Date Date Convicted Regulation Section Penalty Provision Penalty Imposed Date Sentenced
1 Bm11/12 1 December 2008 15th May 2012 3A(3)(b)(i) $80,000.00 (Global) 15th May 2012
2 BM13/12 1 December 2008 15th May 2012 3A(3)(b)(i) $80,000.00 (Global) 15th May 2012
Description of Breach(es)

Charge 1 - Being an employer, the accused did not, so far as practicable, provide and maintain a working environment in which its employee was not exposed to hazards, and by that contravention caused the death of Leon Mobbs.

Charge 2 - Being an employer failed, so far as was practicable, to ensure that the safety or health of a person not being its employee, was not adversely affected wholly or in part as a result of work that has been or was being undertaken by the Accused or any employee of the Accused, and by that contravention caused the death of Geoffrey Lucas contrary to 21(2)(a)(i) of the Occupational Safety and Health Act 1984.

Background Details

The Accused was an oilfields services company that operated a depot at 11 De Castilla Street, Broome.  The depot comprised a yard enclosed by cyclone fencing ("the workplace"). 

At the workplace were two silos, which were used by the Accused for the storage of barite.  Barite is a mineral, which was kept by the Accused as a fine white powder with a high density derived from limestone.  The most common use for barite is as a weighing agent in the offshore drilling process.  Barite was obtained by the Accused, stored in the silos at the workplace, transported from the workplace to vessels moored at the Broome port and then transported by those vessels to drilling rigs/platforms offshore. 

At the workplace, employees of the Accused transferred barite from the silos to road tankers, for transport to the Broome wharf, by using pressurised air, which carried the barite through hoses from the silos to the road tankers.  When barite is dry it has a natural tendency to flow.  A road tanker would often park in between a covered area and the entry gates at the workplace, with the rear of the tanker close to the covered area.  Hoses were then run from the silos to the tanker for the purpose of loading barite.  This method was also used to transfer barite from the road tankers into vessels at the Broome wharf. 

When barite was transferred from a silo to a road tanker at the workplace, and from a road tanker to a vessel, pressurised air was provided by a mobile compressor, which was owned by the Accused.  When barite was transferred from a road tanker to a vessel moored at the Broome wharf, dry air from the mobile compressor was pumped into the inlet manifold of the road tanker through a pressure safety valve and a one-way valve.  The amount of air pumped was controlled by a regulator on the mobile compressor.  The air then entered the aerators at the bottom of the road tanker, thereby building up pressure within the road tanker. The air then escaped from the tanker via discharge lines, carrying the barite with it, to the vessel.

The accident - 1 December 2008

The Accused had contracted with Oilfield Transport Services Pty Ltd ("OTS") for OTS to provide the Accused with two road tankers, to collect the barite from the silos, and deliver it to vessels at the Broome wharf.  The road tankers provided by OTS were a white 3 axle trailer/semi-trailer WA registration BM 12328 ("the white tanker"), driven by OTS employee and a yellow coloured 3 axle trailer/semi-trailer WA registration BM 12256 ("the yellow tanker"), driven by another OTS employee.

 On 1 December 2008, the white tanker and the yellow tanker collected barite from the silos and transported it to the Broome wharf, where it was to be transferred on to a supply vessel.  The weather conditions in Broome on that day, as recorded by the Australian Government Bureau of Meteorology, were temperatures ranging from 26.8 degrees to 31.6 degrees, with nil rain and relative humidity of 72% at 9 am and 64% at 3 pm.

When attempts were made, at the Broome wharf, to transfer the barite from the white and yellow tankers into the supply vessel, it was found that not all the barite in the white and yellow tankers could be pumped into the supply vessel.  That was because the barite contained too much moisture, causing it to cake or clog on the inside of the white and yellow tankers.  That prevented the barite from flowing freely.  It was not known why the barite had become moist.

Different methods were used in attempts to transfer the barite from the white and yellow tankers into the supply vessel, including driving the white and yellow tankers around the wharf to shake the barite down, banging on the hoses and the sides of the white and yellow tankers with a rubber mallet, and increasing the air pressure in the white and yellow tankers.

An employee of the Accused who was involved in the transfer of the barite from the white and yellow tankers into the supply vessel, attempted to facilitate the flow of the barite into the supply vessel by increasing the pressure within the white and yellow tankers.  The Accused's employee increased the pressure within the white and yellow tankers by increasing the opening of the valve on the mobile compressor.  The OTS employee told the Accused's employee to keep the pressure down below a certain level.  However, he continued to increase the pressure. 

Despite the efforts of the Accused's employee and the two OTS employees the bulk of the barite powder could not be transferred from the white and yellow tankers into the supply vessel.  The Accused's employee then directed the two OTS employees to drive the white and yellow tankers back to the workplace. 

The OTS employees drove the white and yellow tankers back to the workplace, where the Accused's employee told them that he wanted to pump the remaining barite from the white and yellow tankers back into the silos.  The OTS employees agreed to that, and the pumping of the barite from the yellow tanker into one of the silos began. 

While barite was being pumped from the yellow tanker into one of the silos, the OTS employee told the Accused's employee that he should reduce the pressure in the yellow tanker.  However, the Accused's employee told the OTS employee that because the yellow tanker was continually getting blocked, it was necessary for him to keep the pressure up.  He then maintained the pressure in the yellow tanker at the same level.

By approximately 2.45pm, all the barite which had been in the yellow tanker when it had returned to the workplace had been transferred into one of the silos. 

The white tanker was then connected to the mobile compressor and its unloading commenced.  However, like the yellow tanker, the white tanker kept getting blocked.  At various stages, the Accused's employee depressurised the white tanker and caused two labour hire workers to enter the white tanker and attempt to scrape down and break free the caked barite.  The Accused's employee depressurised and repressurised the white tanker a number of times, and, on each occasion, the labour hire workers entered the white tanker and endeavoured to scrape down the caked barite.  On the last occasion that the Accused's employee repressurised the white tanker, it ruptured, and exploded, causing the wall of one of the compartments on the white tanker to peel back. 

When the wall of the white tanker peeled back, it struck the Accused's employee and the OTS employee who were standing alongside the white tanker.  As a result of the impact, the Accused's employee and the OTS employee were killed instantly (‘the incident").

Over-pressurisation of the white tanker

A variety of tests conducted after the incident indicated that the accused's employee had pressurised the white tanker well beyond its maximum safe operating pressure.  The maximum safe operating pressure of the white tanker was 14 psi (96 kpa), which was stamped on the data plate on the outside of the white tanker.

Prior to the incident, the Accused failed to provide either their employee or the OTS employee with any training or instructions as to the maximum pressure to which the white tanker could be pressurised without the risk of rupture and explosion. 

At the time of the incident, the Accused's employee had considerable "on the job" experience in working with pressure vessels.  However, neither he nor the OTS employee had available to them, at that time, appropriate documented information available to him in the form of onsite procedures in relation to working with pressure vessels.

At the workplace, the Accused did have in place a generic procedure for ‘Transferring Dry Bulk from a Road Tanker to a Vessel' ("the Dry Bulk Procedure") which stated at point 4.3: ‘ ... Start the compressor and drier and ensure that the regulators are regulating the air pressure to 40 psi.'  However, the Dry Bulk procedure had not been adapted to local conditions for the tankers the Accused was using in Broome. 

The correct operating pressure of 14 psi (96 kPa) was stamped on the data plate of the white tanker.  Had the Accused's employee relied upon the Dry Bulk procedure in pressurising the white tanker, he would have been misinformed as to the maximum pressure to which he could pressurise the white tanker.

The white tanker

At the time of the incident:

  • the white tanker was not registered with WorkSafe WA or any other regulatory authority, as required by regulation 4.14(1) of the Occupational Safety and Health Regulations 1996 ("the OSH Regulations"). Norhad the white tanker been inspected or maintained by a competent person as required by regulation 4.43 of the OSH Regulations.
  • the Accused had not asked OTS whether the white tanker was registered with WorkSafe WA or any other regulatory authority, or whether it had been inspected or maintained by a competent person.
  • the white tanker had undergone approximately nine repairs. The repairs to the white tanker included the welding of patch plates over previous weld joins.
  • the white tanker had pre‑existing faults, including cracks in weld repairs and modifications to the baffle plate between its two compartments. The pre-existing faults in the white tanker compromised its integrity as a pressure vessel and meant that it was unsuitable to be pressurised in the manner carried out by the Accused's employee on 1 December 2008.

Prior to the incident, the Accused had no procedure in place and gave no instruction to its employees to cause any equipment to be used at the workplace to be inspected to ensure that it was safe and, in the case of a pressure vessel, to ensure that it could withstand any pressure which was applied to it.

The pre-existing faults in the white tanker were not detected prior to the incident and, immediately prior to the incident, the Accused's employee increased the pressure in the white tanker to the white tanker without any regard to its integrity or lack thereof.

Accordingly, when the Accused's employee over-pressurised the white tanker on 1 December 2008, a combination of that over-pressurisation and the pre-existing fatigue cracks on the inside surface of the white tanker caused a rupture at the triple point join between the two compartments of the white tanker.

Policies and procedures

The Accused had a number of operational safety procedures in place at its Darwin plant and some copies of documents outlining those procedures were, at the time of the incident, in a filing cabinet at the workplace in Broome.  However, there was no system in place at the workplace to ensure that the plant operators read the procedures (ie, a requirement to read the procedures and acknowledge having read it by signing off).

As previously indicated, at the time of the incident, the Accused did have in place at the workplace the Dry Bulk procedure.  However, that had not been adapted to conditions at the workplace, and would have given the Accused's employee incorrect information about the pressure which the white tanker could withstand.

At the time of the incident, the Accused had no procedure requiring their employee to inspect plant entering the workplace, inspect gauges, data plates or equipment, or any procedure to advise him what items to look for.  Such a procedure has since been implemented by the Accused.  The procedure since implemented is a process whereby information such as plant registration details are captured, and contractors are required to provide copies of certificates of registration to the Accused with regard to their tankers.

At the time of the incident, the Accused had, at its Darwin depot, a safety system of "Stop Cards" whereby any employee who believed an operation was unsafe could submit a "Stop Card" and the operation would immediately cease.  The "Stop Card" system was not in place at the workplace in Broome.




Outcome Summary

The Accused entere a guilty plea to both charges and was convicted.

Court Magistrates Court of Western Australia - Broome
Costs $6500.00 (Global)
Notes

Please note that the charges have a global fine. While a penalty is imposed on each charge it is for the global fine and not a separate amount for each charge.

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