ATSB TRANSPORT SAFETY REPORT Marine Occurrence Investigation No. 272 MO-2010-001 Final Independent investigation into the engine room fire on board the Australian registered bulk carrier River Embley off Gladstone, Queensland 16 February 2010
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ATSB TRANSPORT SAFETY REPORT Marine Occurrence Investigation No. 272
MO-2010-001Final
Independent investigation into the engine room fire on board
the Australian registered bulk carrier
River Embley off Gladstone, Queensland
16 February 2010
Independent investigation into the engine room fi
re on board the A
ustralian registered bulk carrier River Em
bley off Gladstone, Q
ueensland,16 February 2010.
ATSB TRANSPORT SAFETY REPORT Marine Occurrence Investigation
MO-2010-001 No. 272
Final
Independent investigation into the engine room fire on board the Australian
registered bulk carrier
River Embley
off Gladstone, Queensland
16 February 2010
Released in accordance with section 25 of the Transport Safety Investigation Act 2003
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Published by: Australian Transport Safety Bureau Postal address: PO Box 967, Civic Square ACT 2608 Office: 62 Northbourne Avenue Canberra, Australian Capital Territory 2601 Telephone: 1800 020 616, from overseas +61 2 6257 4150
Accident and incident notification: 1800 011 034 (24 hours) Facsimile: 02 6247 3117, from overseas +61 2 6247 3117 Email: [email protected] Internet: www.atsb.gov.au
© Commonwealth of Australia 2011
In the interests of enhancing the value of the information contained in this publication you may download, print, reproduce and distribute this material acknowledging the Australian Transport Safety Bureau as the source. However, copyright in the material obtained from other agencies, private individuals or organisations, belongs to those agencies, individuals or organisations. Where you want to use their material you will need to contact them directly.
ISBN and formal report title: see ‘Document retrieval information’ on page v
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CONTENTS
THE AUSTRALIAN TRANSPORT SAFETY BUREAU ................................ vii
TERMINOLOGY USED IN THIS REPORT ..................................................... ix
EXECUTIVE SUMMARY ................................................................................... xi
1 FACTUAL INFORMATION ........................................................................ 1
1.1 River Embley ........................................................................................ 1
1.1.1 Steam plant ................................................................................ 2
1.1.2 Coal transfer system................................................................... 2
1.1.3 Compressed air systems ............................................................. 2
1.1.4 Fire extinguishing equipment .................................................... 4
1.2 The incident .......................................................................................... 5
2 ANALYSIS .................................................................................................... 13
2.1 Evidence ............................................................................................. 13
2.2 The compressor deck .......................................................................... 13
2.3 The compressor fire ............................................................................ 15
2.3.1 Fuel source............................................................................... 16
2.3.2 Ignition source ......................................................................... 18
2.4 The external fire/explosion................................................................. 19
2.5 Compressor protection devices ........................................................... 20
2.6 Watch keeping practices ..................................................................... 21
2.7 On board emergency response ............................................................ 22
3 FINDINGS ..................................................................................................... 25
3.1 Context ............................................................................................... 25
3.2 Contributing safety factors ................................................................. 25
3.3 Other safety factors ............................................................................. 25
3.4 Other key findings .............................................................................. 26
4 SAFETY ACTION........................................................................................ 27
4.1 ASP Ship Management ....................................................................... 27
4.1.1 Planned maintenance system ................................................... 27
4.2 Champion Compressors ...................................................................... 27
4.2.1 Maintenance manual ................................................................ 27
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APPENDIX A: EVENTS AND CONDITIONS ................................................. 29
APPENDIX B: SHIP INFORMATION .............................................................. 31
APPENDIX C: SOURCES AND SUBMISSIONS............................................. 33
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DOCUMENT RETRIEVAL INFORMATION
Report No. Publication date No. of pages ISBN ISSN 272-MO-2010-001 January 2011 46 978-1-74251-100-9 1447-087X
Publication title Independent investigation into the engine room fire on board the Australian registered bulk carrier River Embley off Gladstone, Queensland, on 16 February 2010.
Prepared By Reference Number Australian Transport Safety Bureau OCT10/ATSB131 PO Box 967, Civic Square ACT 2608 Australia www.atsb.gov.au
Acknowledgements Images used in this report were provided by ASP Ship Management (Figures 8 & 12) and SKF Australia (Figure 14).
Abstract At 0435 on 16 February 2010, the bulk carrier River Embley was at anchor off Gladstone, Queensland, when the ship’s fire alarms sounded, alerting the crew to an engine room fire. A few minutes later, while the engineers were investigating the fire, there was an explosion in the engine room.
The crew shut down the running machinery, the engine room vents were closed and the ship’s electrical load was transferred to the emergency generator. They monitored the situation and at 0823 confirmed that the fire had been extinguished. By 1105, they had determined that the engine room was safe to enter without the use of breathing apparatus.
The ATSB investigation determined that the fire started inside a screw type air compressor and that the explosion that followed occurred when a cloud of hot oil vapour, which had been expelled from the compressor, ignited.
The investigation found that the compressor did not shut down before the fire occurred because its high temperature alarm/shutdown did not operate. The investigation also found that, during the emergency response, the crew worked as a team and demonstrated how effective a trained response to an unexpected emergency can be.
The investigation identified two safety issues: routine testing of the compressor high temperature alarm/shutdown was not included in the ship’s planned maintenance system; and routine testing of the alarm/shutdown was not included in the manufacturer’s maintenance manual.
These safety issues have been addressed by the ship’s managers and the compressor manufacturer.
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THE AUSTRALIAN TRANSPORT SAFETY BUREAU
The Australian Transport Safety Bureau (ATSB) is an independent Commonwealth Government statutory agency. The Bureau is governed by a Commission and is entirely separate from transport regulators, policy makers and service providers. The ATSB's function is to improve safety and public confidence in the aviation, marine and rail modes of transport through excellence in: independent investigation of transport accidents and other safety occurrences; safety data recording, analysis and research; fostering safety awareness, knowledge and action.
The ATSB is responsible for investigating accidents and other transport safety matters involving civil aviation, marine and rail operations in Australia that fall within Commonwealth jurisdiction, as well as participating in overseas investigations involving Australian registered aircraft and ships. A primary concern is the safety of commercial transport, with particular regard to fare-paying passenger operations.
The ATSB performs its functions in accordance with the provisions of the Transport Safety Investigation Act 2003 and Regulations and, where applicable, relevant international agreements.
Purpose of safety investigations
The object of a safety investigation is to identify and reduce safety-related risk. ATSB investigations determine and communicate the safety factors related to the transport safety matter being investigated. The terms the ATSB uses to refer to key safety and risk concepts are set out in the next section: Terminology Used in this Report.
It is not a function of the ATSB to apportion blame or determine liability. At the same time, an investigation report must include factual material of sufficient weight to support the analysis and findings. At all times the ATSB endeavours to balance the use of material that could imply adverse comment with the need to properly explain what happened, and why, in a fair and unbiased manner.
Developing safety action
Central to the ATSB’s investigation of transport safety matters is the early identification of safety issues in the transport environment. The ATSB prefers to encourage the relevant organisation(s) to initiate proactive safety action that addresses safety issues. Nevertheless, the ATSB may use its power to make a formal safety recommendation either during or at the end of an investigation, depending on the level of risk associated with a safety issue and the extent of corrective action undertaken by the relevant organisation.
When safety recommendations are issued, they focus on clearly describing the safety issue of concern, rather than providing instructions or opinions on a preferred method of corrective action. As with equivalent overseas organisations, the ATSB has no power to enforce the implementation of its recommendations. It is a matter for the body to which an ATSB recommendation is directed to assess the costs and benefits of any particular means of addressing a safety issue.
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When the ATSB issues a safety recommendation to a person, organisation or agency, they must provide a written response within 90 days. That response must indicate whether they accept the recommendation, any reasons for not accepting part or all of the recommendation, and details of any proposed safety action to give effect to the recommendation.
The ATSB can also issue safety advisory notices suggesting that an organisation or an industry sector consider a safety issue and take action where it believes it appropriate. There is no requirement for a formal response to an advisory notice, although the ATSB will publish any response it receives.
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TERMINOLOGY USED IN THIS REPORT
Occurrence: accident or incident.
Safety factor: an event or condition that increases safety risk. In other words, it is something that, if it occurred in the future, would increase the likelihood of an occurrence, and/or the severity of the adverse consequences associated with an occurrence. Safety factors include the occurrence events (e.g. engine failure, signal passed at danger, grounding), individual actions (e.g. errors and violations), local conditions, current risk controls and organisational influences.
Contributing safety factor: a safety factor that, had it not occurred or existed at the time of an occurrence, then either: (a) the occurrence would probably not have occurred; or (b) the adverse consequences associated with the occurrence would probably not have occurred or have been as serious, or (c) another contributing safety factor would probably not have occurred or existed.
Other safety factor: a safety factor identified during an occurrence investigation which did not meet the definition of contributing safety factor but was still considered to be important to communicate in an investigation report in the interests of improved transport safety.
Other key finding: any finding, other than that associated with safety factors, considered important to include in an investigation report. Such findings may resolve ambiguity or controversy, describe possible scenarios or safety factors when firm safety factor findings were not able to be made, or note events or conditions which ‘saved the day’ or played an important role in reducing the risk associated with an occurrence.
Safety issue: a safety factor that (a) can reasonably be regarded as having the potential to adversely affect the safety of future operations, and (b) is a characteristic of an organisation or a system, rather than a characteristic of a specific individual, or characteristic of an operational environment at a specific point in time. Risk level: The ATSB’s assessment of the risk level associated with a safety issue is noted in the Findings section of the investigation report. It reflects the risk level as it existed at the time of the occurrence. That risk level may subsequently have been reduced as a result of safety actions taken by individuals or organisations during the course of an investigation.
Safety issues are broadly classified in terms of their level of risk as follows:
• Critical safety issue: associated with an intolerable level of risk and generally leading to the immediate issue of a safety recommendation unless corrective safety action has already been taken.
• Significant safety issue: associated with a risk level regarded as acceptable only if it is kept as low as reasonably practicable. The ATSB may issue a safety recommendation or a safety advisory notice if it assesses that further safety action may be practicable.
• Minor safety issue: associated with a broadly acceptable level of risk, although the ATSB may sometimes issue a safety advisory notice.
Safety action: the steps taken or proposed to be taken by a person, organisation or agency in response to a safety issue.
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EXECUTIVE SUMMARY
At 04351 on 16 February 2010, the Australian registered bulk carrier River Embley was at anchor off Gladstone, Queensland, when the ship’s fire alarms sounded, alerting the crew to an engine room fire.
A few minutes later, while the engineers were investigating the fire, there was an explosion in the engine room. The engineers immediately evacuated the space. The running machinery was shut down, the engine room ventilation dampers were closed and electrical power supply was transferred to the emergency generator.
By 0445, all the crew had mustered. The master and the chief engineer discussed the situation and, since the amount of smoke coming from the engine room skylight was diminishing, they agreed to wait and monitor the situation.
At 0750, two crew members entered the engine room wearing breathing apparatus (BA) sets. When they exited, they reported that there was still a small fire burning on the air compressor deck. The two crew members returned with a portable fire extinguisher and put the fire out. The crew monitored the situation and at 0823 confirmed that the fire had been extinguished. By 1105, they had determined that the engine room was safe to enter without the use of breathing apparatus.
During the emergency response, two crew members reported that they were experiencing breathing difficulties, so they were given oxygen to assist with their breathing. Gladstone vessel traffic service was advised and a helicopter evacuation was arranged. At 0836, the helicopter landed on the ship and by 0937, it had departed with the two crew members on board. The two crew members were taken to hospital for further treatment and were discharged later that day.
The engineers returned to the engine room and began restarting the machinery and lighting that had not been affected by the fire. Later, with assistance from ashore, they began testing the various engine room systems. On 20 February, the ship was taken to sea for trials prior to entry into the port. By 1818 that day, the ship was all fast at South Trees wharf.
The ATSB investigation determined that the fire started inside a screw type air compressor. It is likely that the compressor thermostatic valve failed to operate correctly. As a result, the temperature of the oil in the compressor increased until it reached its flashpoint2. The oil was then ignited, probably by a hot spot within the compressor.
The subsequent fire caused the pressure in the compressor air receiver to rise until its safety valve lifted, relieving the pressure and expelling large quantities of hot oil vapour into the engine room. It is likely that, when the concentration of oil vapour entered its explosive range3, it was ignited by either an expulsion of flame from the safety valve or a hot metal surface on the compressor.
1 All times referred to in this report are local time, Coordinated Universal Time (UTC) + 10 hours. 2 The lowest temperature at which the vapours from a volatile oil will ignite in air when exposed to
an ignition source. 3 The lower explosive limit (LEL) is the minimum concentration of a particular combustible gas or
vapour necessary to support its combustion in air. Below this level, the mixture is too ‘lean’ to
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The ATSB investigation found that the compressor did not shut down before the fire occurred because its high temperature alarm/shutdown did not operate. The investigation also found that, during the emergency response, the crew worked as a team and demonstrated how effective a trained response to an unexpected emergency can be.
The investigation identified two safety issues: the ship’s planned maintenance system did not require routine testing of the compressor alarm/shutdown; and the manufacturer’s maintenance manual did not include a requirement for the routine testing of the compressor alarm/shutdown.
These safety issues have been addressed by the ship’s managers and the compressor manufacturer.
burn. The maximum concentration of a gas or vapour that will burn in air is defined as the upper explosive limit (UEL). Above this level, the mixture is too ‘rich’ to burn. The range between the LEL and UEL is known as the explosive range.
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1
1.1
FACTUAL INFORMATION
River Embley River Embley is a bulk carrier (Figure 1) with three cargo holds, serviced by eight hatches, located forward of the accommodation superstructure. It was specifically designed and built for the bauxite trade between the Queensland ports of Gladstone and Weipa.
The ship was built in 1983 by Mitsubishi Heavy Industries, Nagasaki, Japan. It has a deadweight of 76,358 tonnes at a summer draft of 12.321 m, an overall length of 255 m, a beam of 35.35 m and a depth of 18.29 m.
Propulsive power is provided by a single 13,976 kW Mitsubishi MS-21-2 marine steam turbine, driving a five bladed, highly skewed propeller through a reduction gearbox, giving the ship a service speed of 14.5 knots4.
Figure 1: River Embley
At the time of the incident, River Embley was registered in Australia, owned by the Australian River Company, managed by ASP Ship Management (ASP) and classed with Lloyd’s Register (LR).
The ship’s crew was made up of 22 Australian nationals and included a master, three mates, five engineers, a chief integrated rating (CIR), six integrated ratings (IRs), two caterers and four trainees. A company training officer was also on board the ship at the time of the incident.
The three mates maintained a traditional watch keeping routine of 4 hours on, 8 hours off, while the engineers followed a 24 hour duty roster, with the engine room operating un-manned outside normal daylight working hours.
4 One knot, or one nautical mile per hour equals 1.852 kilometres per hour.
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River Embley’s master started his seagoing career in the Royal Australian Navy. After completing 10 years of naval service, he spent 33 years working on board merchant ships. He held an Australian class one master’s certificate of competency and had been serving as a ship’s master for 13 years. He had been River Embley’s master for about 2 years.
The chief engineer had 44 years of seagoing experience. He held a combined steam and motor first class certificate of competency. He had been assigned to ASP’s fleet of coal fired steam ships for about 25 years and had been sailing as chief engineer for about 20 years.
The second engineer, the duty engineer at the time of the incident, had 6 years of seagoing experience, with most of that time spent on coal fired steam ships. He held an Australian watch keeper’s certificate of competency and had been sailing as second engineer on board River Embley for about a year.
1.1.1 Steam plant
River Embley is fitted with two coal-fired, high pressure, water tube boilers which were designed to burn the type of bunker coal that is readily available in Gladstone. The boilers were designed by Associated Combustion and built by Mitsubishi Heavy Industries.
Coal is supplied, as required, from daily hoppers to a set of three spreaders, which feed coal onto a moving chain grate in the furnace. The heat in the furnace ignites the coal, which then burns as the grate moves it through the furnace. At full sea speed, the boilers consume approximately 220 tonnes of coal per day.
The boilers are rated at 480ºC and 60 bar5 and can produce up to 64,000 kg of steam per hour. The steam is supplied to the main propulsion turbine, two turbo alternators and two feed water pumps. The residual heat in the exhaust steam is used to improve the plant’s efficiency by passing it through the de-aerator, the main boiler air heaters and evaporators. Any excess exhaust steam is dumped into the main condenser.
1.1.2 Coal transfer system
The coal is stored in two bunkers located aft of the accommodation superstructure (Figure 1). From there, it is transferred to the daily hoppers using a dense phase coal transfer (denseveyor) system. The system uses large quantities of compressed air to push slugs of coal through pipes.
1.1.3 Compressed air systems
River Embley had two independent compressed air systems. Two control air compressors supplied compressed air to the various automation control systems. A bunkering compressor and three coal conveying compressors supplied compressed air to the coal transfer and general service systems. When necessary, compressed air for the control air system could be supplied from the coal transfer/service air system by opening a crossover valve.
5 1 bar equals 100 KPa or approximately one atmosphere.
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Two of the coal transfer compressors were reciprocating type compressors and the third, a retro-fitted unit, was a screw type air compressor. The reciprocating compressors were rarely used because of the high level of maintenance that was required to keep them operating efficiently. Therefore, the number three coal transfer compressor, the screw compressor, was run most of the time.
When number three coal transfer compressor was unavailable for use, rather than running one, or both, of the reciprocating coal transfer compressors, the engineers preferred to use the bunkering compressor, also a screw type compressor, to supply compressed air to the coal transfer/service air system.
Number three coal transfer compressor
The number three coal transfer compressor was a Sullair packaged water-cooled air compressor (Figure 2). The compressor package included a compressor unit, a receiver, separator, cooling system, lubrication system and an instrument/control panel, all mounted on a heavy gauge steel frame.
Figure 2: Diagram depicting a similar air cooled Sullair compressor
The compressor unit was a single stage positive displacement screw type compressor, designed to provide continuous pulse free air compression. Lubricating oil (fluid) was injected directly into the compressor unit and mixed with the air as the screws rotated, compressing the air. The fluid had three primary roles: to control the normal temperature rise associated with the compression of air; to seal the leakage paths between the rotors and the stator; and to act as a lubricating film between the rotors.
The compressed fluid/air mixture discharged from the compressor unit through a check valve and into a receiver, where the fluid was separated from the air. The air flowed from the receiver to the service air line and the fluid was retained in the receiver. The fluid was then returned to the compressor unit for re-injection. When the fluid temperature was below 80°C, it was supplied directly to the compressor for re-injection. When the temperature exceeded 80°C, a thermostatic valve operated, directing the oil through the cooler prior to re-injection (Figure 3).
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Figure 3: Schematic of a similar air cooled Sullair compressor with the fluid path depicted by black arrows
The fluid used in the compressor was Shell Corena AS 46 synthetic oil. This oil has a flashpoint6 of 235°C, an auto ignition temperature7 of 320°C, a lower explosive limit of 1% by volume and an upper explosive limit of 10% by volume.
Under normal conditions, once the compressor was started, it ran continuously. Its output was modulated, as necessary, by a pneumatically operated diaphragm, which controlled a butterfly valve mounted in the compressor unit air inlet.
1.1.4 Fire extinguishing equipment
River Embley’s engine room was equipped with portable fire extinguishers; a fire main and the associated fire hydrants, hoses and nozzles; and a water spray system over the main propulsion turbine and the turbo-alternators. Since the boilers were
6 The lowest temperature at which the vapours from a volatile oil will ignite in air when exposed to an ignition source.
7 The lowest temperature at which the material will ignite due to heat, without the introduction of an ignition source.
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1.2
fired by coal, and not fuel oil, the engine room was not fitted with a fixed carbon dioxide or halon fire extinguishing system.
The incident At 14248 on 15 February 2010, River Embley’s port anchor was let go in the Gladstone anchorage following a voyage from Weipa. The ship was scheduled to remain at anchor for about 2 days while waiting for a berth.
After the master had finished with the main engine, the second engineer, the duty engineer, prepared the engine room for the stay at anchor. Both boilers were left firing at a reduced steam output and the steam supply valves to the main engine were shut.
The second engineer completed an inspection of the engine room and conducted a set of boiler water tests. He also attempted to identify the source of two coal transfer denseveyor blockages. At 1800, he left the engine room to have dinner.
At 2000, the second engineer and the duty engine room IR returned to the engine room to complete their night rounds. By 2100, the IR had completed his rounds and left the engine room. The second engineer completed his inspection and again attended to the blocked denseveyors, clearing one. At 2200, he left the engine room and went to his cabin.
At about midnight, the second engineer was awakened by an engine room alarm. He went to the engine room to investigate the cause and found that it was a denseveyor no-flow alarm. He accepted the alarm and it reset, so he returned to bed.
At about 0100 on 16 February, the second engineer was again awakened by another engine room alarm. He went to the engine room to investigate the alarm and found that the running control air compressor had shut down due to a high discharge air temperature. He opened the crossover valve between the control air and general service air systems and then inspected the shut down control air compressor. While he found no obvious faults, he decided to run the second control air compressor in its place. Once the compressor was running he closed the crossover valve.
The second control air compressor ran for about half an hour before it also shut down due to high discharge air temperature. The second engineer again opened the crossover valve. He then inspected both compressors in an attempt to determine what the problem was. He confirmed that there were no problems with the cooling water supply but he could not find the source of the overheating problem. He started the compressor that had originally been running but it soon shut down again.
The second engineer telephoned the first engineer and reported that there was a problem with the control air compressors. He told the first engineer that he had opened the crossover valve and that he was going to leave the control air compressors shut down until the morning. He also told him that since the demand for air from the two compressed air systems could, at times, exceed the capacity of the running coal bunkering compressor, he would start the number three coal transfer compressor. The first engineer agreed with the second engineer’s thoughts so, after hanging up the phone, the second engineer started the number three coal transfer compressor and, at about 0330, went back to bed.
All times referred to in this report are local time, Coordinated Universal Time (UTC) + 10 hours.
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At 0435, the ship’s fire alarms sounded. The chief mate, the duty bridge watch keeper, checked the fire alarm panel and saw that it indicated a fire on the engine room third deck (Figure 4). He left the alarm sounding for about 30 seconds to allow the crew some time to respond and then silenced it. Soon afterwards, the fire alarms sounded again, this time indicating a fire on both the engine room second and third decks.
Figure 4: Section of River Embley’s general arrangement plan
Meanwhile, the second engineer had responded to the first fire alarm. When he entered the engine room uptake casing from the second cabin deck, he could see a small trail of white smoke coming from the aft end of the engine room, below the engine room second deck. He considered that it was safe to enter so he proceeded to the control room which was located on the engine room second deck.
The first engineer and the engineer cadet (cadet) entered the engine room about a minute later. By this time, all they could see was a cloud of white smoke, but it was not dense so they began to make their way to the control room.
Soon afterwards, the chief engineer tried to enter the engine room uptake casing from the second cabin deck. The smoke was now dense and allowed little visibility. The chief engineer thought that the smoke smelt ‘oily’ and considered that it was unsafe to enter, so he went to the muster station on the aft bunker deck.
The third engineer also tried to enter the engine room, but he too thought there was too much smoke, so he went to close the accommodation and engine room fire dampers.
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When the second engineer arrived at the control room, the telephone was ringing. He answered it and the chief mate asked him what was happening. He responded, confirming that there was a fire in the engine room. He then set off the engineers call alarm.
At 0437, the chief mate sounded the emergency muster signal. He also told the CIR, via hand held radio, to make sure that everyone got out of the accommodation and went to the muster station on the aft bunker deck.
At about this time, the master and the third mate arrived on the bridge. The master looked aft out of the bridge windows and could see white smoke billowing from the open engine room skylight. He then sent the chief mate to the bunker deck to oversee the mustering of the crew; to prepare a fire party; and to set up fire hoses in case they were needed for boundary cooling.
Figure 5: View from the position where the second engineer was standing
Meanwhile, the second engineer had left the control room in an attempt to find the source of the smoke. He stood at the port side railing, just aft of the control room, and looked down and aft towards the source of the smoke (Figure 5). He could see a steady orange glow about amidships at the after end of the engine room. However, he could not determine exactly which deck it was on. The smoke was still white, but it was getting thicker and he did not think it was safe to get any closer.
The second engineer was on his way back to the control room to update the bridge, when he met the first engineer and the cadet. They agreed that the first engineer and the cadet would go and investigate the fire further and the second engineer would continue to the control room. The second engineer went to the control room and stopped the engine room supply and exhaust fans.
The first engineer and the cadet went forward, across the walkway on top of the port boiler, and then started making their way down the ladders at the forward end of the engine room. The first engineer intended to go forward, get below the fire and then try and make his way up to the seat of the fire from below. When the two men reached the third deck, just forward of the starboard boiler, they heard a loud explosion. They felt its force push against their chests; dust, flakes of paint and
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other debris flew around them and visibility immediately reduced. Now, they could not see beyond about a metre. The first engineer yelled ‘let’s get out of here’ and they re-traced their steps to the control room.
The second engineer was still in the control room when the explosion occurred. The control room doors blew open and the room filled with smoke. The front covers on the air-conditioning units flew off, pushing the equipment stored in front of them across the room (Figure 6). The second engineer began preparing the two control room emergency life saving appliances (ELSA) for use and, while he was doing so, the first engineer and the cadet came through the control room door.
Figure 6: Photograph of the control room showing the air-conditioning cabinet front panels and equipment normally stored in front of them
The second engineer and the cadet each donned an ELSA and the first engineer put on a smoke helmet. They then started to make their escape. By this time, there was zero visibility, so the first engineer led the way towards the port aft engine room stairs using the hand rails as a guide and shining a torch behind him for the others to follow. The three men made their way aft and then up the port side stairwell, exiting the engine room at the boat deck. They then went up one flight of stairs in the accommodation to the first cabin deck, where they met other crew members, including the chief engineer, who were breaking out breathing apparatus (BA) sets. While they were explaining what they had experienced, there were two smaller explosions in rapid succession. When the three men had finished explaining what they had seen, they went out on deck to get some fresh air. The chief engineer then instructed the crew preparing the BA sets not to enter the engine room.
Meanwhile, when the master heard the first explosion, he thought the noise was the engine room skylight being slammed closed, but when he looked out, he saw a large cloud of smoke and dust blow through the open skylight. The crew were mustering on the bunker deck at the time and they were showered with small pieces of debris that had been blown out of the skylight and the engine room ventilators that had not yet been closed (Figure 7).
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Figure 7: View from the bunker deck showing the aft engine room ventilators
By 0445, all the crew had been accounted for and the chief mate had readied a BA party on the poop deck for an engine room entry through the steering compartment.
At about the same time, the chief engineer sent the fourth engineer to start the emergency generator. The chief engineer and the first engineer agreed that they needed to shut down the engine room machinery, so they went to the bridge to discuss the situation with the master. They master agreed with their suggestion, so they went to the first cabin deck, where they operated the boiler and associated machinery remote stops.
The chief engineer and the first engineer then went to the emergency generator room and opened the tie breaker to the main switchboard, which, with the exception of the emergency circuits, blacked-out the ship. They then opened all the circuit breakers supplying the engine room emergency circuits. These circuits included the lighting and essential pumps supplied from the emergency switchboard.
At 0452, the master reported the fire and explosion to the Gladstone vessel traffic service (VTS) and, at 0455, the chief engineer telephoned ASP’s Gladstone fleet manager to inform him what had happened and what actions were being taken.
The master decided that it was unsafe to let anyone enter the engine room at this stage and at 0500, he ordered all the crew to muster on the bridge. He and the chief engineer discussed the situation and the chief engineer explained that the oily smell of the smoke, the location of the seat of the fire and the fact that number three coal transfer compressor was the only running item of machinery in that area, indicated that the compressor was the likely source of the fire. They discussed the fact that the electrical power supply to the engine room had been isolated and that the amount of smoke that was coming from the engine room skylight was diminishing, indicating that the fire was not getting any bigger. The two men agreed to wait and to continue monitoring the situation.
The amount of smoke coming from the open engine room skylight continued to diminish and the master could, over time, see further into the engine room through the skylight. At about 0600, the master and the chief engineer agreed that the fire had probably burnt itself out, so they decided to ventilate the engine room by opening the engine room ventilation dampers.
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At about 0610, the second engineer reported that he felt unwell and was having difficulty breathing. He was told to lie down on the bridge settee and was given oxygen to assist with his breathing.
At 0612, the master called Gladstone VTS and requested a medical evacuation (medivac) for the second engineer. At 0636, Gladstone VTS advised the master a helicopter had been tasked for the medivac.
At 0657, Gladstone VTS advised that the medivac helicopter could not take off due to the poor weather conditions and hence, the medivac would be delayed.
At 0700, the cadet advised that he was also feeling unwell and was having difficulty breathing. He was treated similarly to the second engineer.
At 0703, the Queensland ambulance service telephoned the master to discuss the treatment the two men were receiving. The master was advised to continue with the treatment and that there was little else he could do.
At 0735, the master and the chief engineer decided that the smoke in the engine room had cleared sufficiently to allow a fire party to enter. It was agreed that the fourth engineer and one of the IRs would don BA sets, enter the engine room through the steering compartment and make their way to the control room. They were instructed to start the engine room ventilation fans and restore power to the galley and the domestic fresh water pumps. They were also told to check the area where the fire damage was greatest, but not to get too close.
The emergency switchboard tie breaker was closed again so that power would be available on the main switchboard to allow the men to carry out these tasks and the steering compartment exhaust fan was started in order to clear any smoke that may have built up in the space.
At 0750, the fourth engineer and the IR entered the steering compartment on their way to the engine room. At 0757, they exited the steering compartment and reported that they had completed their tasks and that there was only a small ‘candle like’ fire remaining beneath the number three coal transfer compressor.
At 0808, the fourth engineer and the IR, again wearing BA sets, returned to the engine room. This time they carried a dry powder fire extinguisher. At 0823, they exited the steering compartment and reported that the fire had been extinguished.
At 0836, the medivac helicopter landed on the ship’s deck. A paramedic was taken to the bridge to assess the condition of the second engineer and the cadet. Since the first engineer was also in the engine room for a period of time with the other men, his condition was also assessed by the paramedics.
At 0845, the master informed the crew that the emergency was over and that they could return to the accommodation.
The paramedics decided that the first engineer did not need any assistance, but that the second engineer and the cadet required further medical treatment and should be taken ashore to the Gladstone hospital. At 0937, the helicopter departed the ship with the men on board.
At 1030, the chief engineer and the third engineer entered the engine room wearing BA sets so that they could assess the damage and test the atmosphere. At 1050, they exited the engine room. They confirmed that the damage appeared to be confined to the area around the number three coal transfer compressor but they were unable to
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get a reliable atmosphere reading. One of their personal gas meters was all clear, but the other was alarming.
At 1055, the first engineer and the fourth engineer entered the engine room wearing BA sets in another attempt to test the engine room atmosphere. At 1105, they reported, via hand held radio, that it was now safe to enter the engine room without the use of a BA set. The two men then returned to the deck, exiting the steering compartment at 1115.
The engineers returned to the engine room and began restarting the machinery and lighting that had not been affected by the fire. They made no attempt at this time to re-fire the boilers or to start their associated systems.
At 1200, ASP’s Gladstone superintendent arrived on board by helicopter. About an hour later, the master, the chief engineer, the chief mate and the superintendent went to the engine room to inspect the damage.
The engineers, with the assistance of the superintendent, began testing machinery and electrical circuits that they considered may have been damaged by the fire.
Later in the day, the second engineer and the cadet were discharged from hospital after they had been treated for smoke inhalation and on 17 February, they returned to the ship.
At 0907 on 20 February, River Embley’s anchor was weighed and the ship was taken to sea for engine trials. When the trials were successfully completed, the master set a course for Gladstone. A harbour pilot boarded the ship at the pilot boarding ground and then conned it into Gladstone harbour. By 1818, the ship was all fast at South Trees wharf.
While River Embley’s cargo was being discharged, a Lloyd’s Register surveyor attended the ship. The surveyor issued the master with a condition of class which required the repair or replacement of the compressor and the repair of the damaged electrical equipment in the engine room. The air compressor was removed from the ship and the necessary engine room repairs were carried out to enable the ship to depart Gladstone.
On 23 February, the ship departed Gladstone bound for Weipa. The condition of class remained in force until all the repairs had been carried out to the satisfaction of Lloyd’s Register.
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2 ANALYSIS
2.1 Evidence On 17 February 2010, two investigators from the Australian Transport Safety Bureau (ATSB) attended River Embley while the ship was at anchor off Gladstone, Queensland. The master and directly involved crew members were interviewed and they provided accounts of the incident. Photographs of the ship and copies of relevant documents were obtained, including log books, statutory certificates, reports, manuals and procedures.
Following the fire, the air compressor and its associated equipment was inspected by the ATSB’s investigators. The equipment was later removed from the ship and forwarded to Champion Compressors, the Australian subsidiary of Sullair compressors, where it was stripped down for further inspection. The bearings were removed from the compressor and inspected by SKF Australia.
Throughout the course of the investigation, further information was provided by ASP Ship Management.
2.2 The compressor deck The damage that resulted from the fire/explosion was confined almost entirely to the compressor deck and was greatest on and around the number three coal transfer compressor (Figure 8). However, other components located within a radius of about 3 m from the compressor had also been damaged.
Figure 8: Fire damaged number three coal transfer compressor
The lighting in the area, an alarm sounder, a combination flashing lamp/siren and a fire detector were all damaged as a result of the fire. The paint had been burnt off the ventilation ducting directly above the compressor and electrical cable runs, directly above and to port and starboard, showed signs of charring of the outer sheathing.
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Figure 9: Starboard compressor flat bulkhead
Figure 10: Fire damage on and around the number three coal transfer compressor
On the starboard bulkhead, there was a spray pattern of oil vapour/droplets that had run down the bulkhead, washing off some of the smoke and soot marks (Figure 9). This suggests that the compressor was still running after the first explosion and that oil was spraying from it.
The compressor unit showed signs that it had been exposed to a great deal of internal heat and the air filter showed signs of heat damage and oxidation, indicating that it had been burnt (Figure 10).
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2.3
The paint had peeled off the receiver, indicating that there had been a source of intense heat inside. However, the receiver was not deformed and there was no evidence to suggest that the explosion occurred within the receiver or compressor.
There was, however, evidence of a powerful blast. The compressor air filter had been dislodged from the compressor unit, steel mesh and canvas doors located at the aft end of the compressor flat had been blown off their hinges and severely bent and small items of debris had been blown all around the engine room.
The evidence indicated that there had been an intense fire inside the compressor and that this primary fire led to an explosion in the engine room.
The compressor fire An inspection of the compressor indentified a ‘hot spot’ on the starboard side of the receiver/separator chamber where the paint had been burnt back to base metal (Figure 11).
Figure 11: Receiver/separator ‘hot spot’
The receiver was dismantled and the separator elements were removed. An internal inspection identified that the air inlet pipe elbow beneath the separator cartridge was heat affected, but only directly below the cartridge (Figure 12). This indicates that the heat had been directed downwards from within the separator cartridge and was, therefore, not blown into the receiver from the compressor.
The separator cartridges were badly burnt and the inner cartridge cover had come free (Figure 13). The amount of damage caused to these elements suggests that the primary fire was in the separator.
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Figure 12: Inlet pipe
Figure 13: Fire damaged separator elements
2.3.1 Fuel source
The only fuel source available within the compressor was its lubricating oil (fluid). However, the fluid had to be either heated to its flashpoint (235°C) and ignited by a source of ignition; or heated to its auto ignition temperature (320°C), when it would ignite without a source of ignition.
An inspection of the compressor unit’s eight bearings, carried out following the incident, found that they all exhibited heat discolouration from straw to blue colours. This indicates that the bearings had been heated to a temperature in the
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range of 230 to 300°C. The five bearings with polyamide9 cages (melting point of approximately 340°C) all showed a similar pattern of cage material melting and solidifying in a mass at the bottom of the bearing (Figure 14). This indicates that the polyamide cages did not get hot enough to melt until after the compressor had stopped.
Figure 14: Compressor bearing showing the melted polyamide material
The evidence indicates that the fire started while the compressor was running and that the fluid did not reach its auto ignition temperature (320°C) before the compressor stopped. Therefore, it is likely that the fluid was heated to at least its flashpoint (235°C) when it was ignited.
Fluid temperature increase
An increase in the fluid temperature within the compressor can be caused by a lack of fluid, the failure, or impending failure, of a rotating component within the compressor unit, or the failure of the fluid cooling system.
An internal inspection of the receiver showed that there was still fluid inside it, albeit at a lower level than normal, and an inspection of the bearings and rotors indicated that they were receiving lubrication throughout the event. Therefore, a lack of fluid is not considered to be the cause of the temperature increase.
When the compressor’s internal components were inspected, there was no sign of metal to metal contact between the compressor rotors and the stator housing or the low pressure and high pressure housings. While the compressor bearings exhibited
Polyamides (nylons) comprise the largest family of engineering plastics with a wide range of applications.
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9
heat discolouration, all the bearing rolling elements and raceway surfaces were in good condition and there were only minimal indentations due to contamination.
This evidence, and the fact that the bearing cage damage probably occurred after the compressor had stopped, indicates that the compressor rotating components were not the source of the heat that caused the increase in fluid temperature.
Therefore, it is likely that the fluid temperature progressively increased because the cooling system failed to adequately cool it. Either the supply of cooling water was insufficient to cool the fluid or the thermostatic valve failed and the fluid was bypassing the cooler.
After the incident, the ship’s engineers confirmed that there was no link between the control air compressor problems and the oil cooling issues that lead to the fire in the number three coal transfer compressor. They also checked the supply of cooling water to the number three coal transfer compressor fluid cooler and confirmed that it was satisfactory.
Therefore, it is likely that the number three coal transfer compressor thermostatic valve failed; and that, as a result, the fluid was not directed through the cooler before re-injection. However, it could not be positively determined that the thermostatic valve had failed because it was not inspected following the fire.
2.3.2 Ignition source
The most likely mechanisms for an ignition source within the compressor are: a spark created due to the build up of static charge between the separator elements and the receiver; a blocked separator element: or a hot spot or spark produced within the compressor unit.
The build up of static charge between the receiver chamber and the separator elements due to the friction caused by the air passing through the elements was a consideration in the design of the compressor. Hence, the separator elements were earthed to the receiver to ensure that such a charge could not build up.
When the separator/receiver was inspected following the incident, the earthing staples on the separator elements were sitting proud of the gaskets and the markings on the metal surfaces of the receiver showed good contact. There were also no signs of arcing visible on, or near, the earthing staples. This indicates that the staples had been earthing correctly. As a result, it is unlikely that a spark was created in the separator as a result of static charge build up.
The ship’s maintenance records showed that the separator element had been cleaned and replaced as required by the maintenance manual. Furthermore, the inspection of the element after the fire showed no obvious point of ignition. Hence, it is unlikely that the fire started because of a blocked separator.
Therefore, it is likely that the fluid was ignited by a hot spot or spark from within the compressor unit. The viscosity10 of the fluid would have been greatly reduced11
as it reached its flashpoint. As a result, the fluid’s lubricating properties would have
10 Viscosity is a measure of the resistance of a fluid which is being deformed by either shear stress or tensile stress. In everyday terms the viscosity of a fluid refers to its ‘thickness’. Thus, water is ‘thin’, having a lower viscosity, while honey is ‘thick’, having a higher viscosity.
11 The viscosity of a liquid decreases with increasing temperature.
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2.4
been significantly diminished. It is possible that, as the lubricating film began to break down, there was a momentary touch between two moving metal surfaces within the compressor unit. This would have been enough to create a momentary hot spot or spark that was sufficient to ignite the fluid that had already been heated to, or beyond, its flash point.
The external fire/explosion It is likely that the internal compressor fire caused the receiver pressure to steadily increase. The pressure continued to increase until the receiver safety valve lifted. The recently overhauled and tested safety valve had only just been fitted to the receiver and an inspection of it after the incident showed signs of carbon residue, indicating that it had lifted during the event (Figure 15).
When the safety valve lifted, large quantities of hot oil vapour were expelled into the engine room atmosphere. It was probably this cloud of hot oil vapour that the engineers described as ‘an oily smelling white smoke’.
Figure 15: Carbon residue inside the receiver safety valve
The quantity of oil vapour in the atmosphere continued to increase and when the vapour entered its explosive range12, it was ignited by a heat source.
The vapour cloud’s source of ignition could not be positively identified. However, it is likely that it was ignited by either an expulsion of flame from the safety valve or a hot metal surface on the compressor or receiver. The results of the relief valve inspection indicate that it is possible that a flame had been expelled through it. Similarly, the evidence provided by the second engineer when he saw an orange glow in the vicinity of the compressor and the inspection of the compressor
12 The lower explosive limit (LEL) is the minimum concentration of a particular combustible gas or vapour necessary to support its combustion in air. Below this level, the mixture is too ‘lean’ to burn. The maximum concentration of a gas or vapour that will burn in air is defined as the upper explosive limit (UEL). Above this level, the mixture is too ‘rich’ to burn. The range between the LEL and UEL is known as the explosive range.
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2.5
following the fire indicate that the surface temperature of either the receiver or the compressor unit was probably sufficient to ignite the vapour cloud.
The explosion that followed was probably the result of the deflagration13 of the large cloud of oil vapour that was present in the engine room at that time. The lack of fire-related damage surrounding the compressor indicates that the deflagration self extinguished once the oil vapour was consumed or its concentration became too low to support a flame.
The two smaller explosions that occurred in succession a short time later were probably the result of the same sequence of events. However, by this time, the vapour cloud was much smaller.
Compressor protection devices The number three coal transfer compressor was fitted with a high temperature alarm and shutdown. The alarm/shutdown was designed to protect the compressor from fire and internal damage to bearings and other components, by shutting it down before any damage should occur. According to the manufacturer’s maintenance manual, the alarm/shutdown should be set to operate at 115°C, well below the flashpoint of the system fluid.
However, on 16 February, the alarm/shutdown did not operate. As a result, the duty engineer was not alerted to the developing situation and the compressor was not shut down. Had the device operated correctly, the fire and explosion would not have occurred.
In submission, Champion Compressors stated that:
It should be noted that the compressor temperature shutdown probe is located at the discharge of the air end. It is not uncommon for an older compressor equipped with a single probe in this position to continue to run even when the machine has an internal fire in progress for at least some period. The draft report noted that there was still some lubricant in the machine although the level had dropped from the normal operational level. Lubricant is circulated by differential pressures and as such provided there is positive pressure applied to the oil in the vessel the compressor will continue to run even though there is a fire in progress. The result can be devastating in that the machine becomes a flame thrower with flame from the safety valve or as a result of flexible lines igniting or melting.
Generally, critical machinery alarms and shutdowns are tested at defined intervals to ensure that they operate correctly. However, there were no records on board River Embley to indicate that the number three coal transfer compressor high temperature alarm/shutdown had ever been tested. Furthermore, the engineers interviewed by the ATSB investigators following the incident had no knowledge of the alarm/shutdown being tested during their time on board the ship.
The compressor’s original alarm/shutdown electrical circuitry was replaced a few years before the incident because it was unreliable and some of its components were no longer supported by the manufacturer. The original printed-circuit-board based
13 Deflagration is a combustion process that progresses radially outwards at sub-sonic speeds from its ignition source and through the available air/fuel mixture. As the volume of the reaction zone expands with every passing moment, the larger surface area contacts more fuel.
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2.6
alarm circuitry was replaced by a locally designed and sourced relay based system. While the operation of the alarm/shutdown would have been tested when this modification was made, there were no records on board the ship to indicate that it was.
River Embley’s planned maintenance system (PMS) contained detailed instructions outlining the various levels of maintenance that the number three coal transfer compressor required. However, these maintenance requirements did not include the testing of the compressor’s alarm/shutdown.
The PMS instructions closely mirrored those in the manufacturer’s maintenance manual. However, these instructions also did not include the routine testing the high temperature alarm/shutdown.
While River Embley’s engineers had maintained the number three coal transfer compressor in line with the manufacturer’s and PMS requirements, the high temperature alarm/shutdown had not been routinely tested to ensure its correct operation.
Watch keeping practices At about 0330 on 16 February, when the duty engineer started the number three coal transfer compressor, he did so by pushing the start button on the compressor starter panel in the engine control room. Shortly afterwards, he left the engine room and went back to bed.
At 0330 in the morning, the second engineer was probably tired, following a night of broken sleep attending to engine room call outs. As a result, he may not have been as focused on the task at hand as he would have been had he been adequately rested.
While many of the effects associated with fatigue, like slowed reaction time, decreased work efficiency and increased errors or omissions only appear after substantial levels of sleep deprivation, even the loss of sleep for one night can have negative effects on human performance. Therefore, it is possible that because the second engineer was tired, he may have lacked the motivation required go to the compressor deck to check the compressor after it had been started.
However, the second engineer had inspected the shut down number three coal transfer compressor at least four times during his gear-turn and checked it again in the early hours of the morning of 16 February as part of his control air compressor fault diagnosis. He was aware that the compressor had previously been operating without fault and felt that he had no doubts about the compressor’s physical condition.
Traditionally, watch keeping engineers were trained to check machines, like air compressors, before starting them; and then confirm that the machine’s operating parameters had settled to their normal state after the machine had been running for a short period of time. However, today, this good engineering practice is often being disregarded. Many items of machinery are started and stopped automatically and engineers often start machines remotely without checking them once they are running.
Engineers have, over time, become more and more reliant on automation. However, while automated shutdowns and alarms can react to changes in system parameters,
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2.7
they are not as effective as a human in predicting future problems based on early diagnosis. Well trained engineers can use all their senses to determine if something is wrong or if a system parameter is different to normal before it reaches a critical ‘shutdown’ stage.
These observations have been supported by a number of researchers. In his book ‘Investigating Human Error’, Barry Strauch states:
Researchers have obtained considerable evidence demonstrating that increasing automation and decreasing operator involvement in system control reduces operator ability to maintain awareness of the system and its operating states. Endsley and Kaber (1999) found that among various levels of automation, people perform best when actively involved in system operation. Endsley and Kiris (1995) term the reduced operator involvement in system control in highly automated systems the "out-of-the-loop performance problem." They attribute reduced operator ability to recognise system anomalies in automated systems to three factors, 1) reduced vigilance and increased complacency from monitoring instead of active system control, 2) passive receipt of information rather than active information acquisition, and 3) loss or modification of feedback concerning system state.
Since the fire in the compressor occurred within an hour of it starting, it is likely that all was not well with the compressor when it was started. Had the second engineer attempted to actively acquire information by inspecting the compressor after he had started it, he may have detected a higher than normal oil temperature, a sound, a smell, or something else that may have indicated to him that all was not right. He could have then taken appropriate action and possibly prevented the fire and explosion.
In submission, the second engineer stated that:
Even if I had stood at the machine to check its operation on start up the problem may not have been detected straight away and the fire could still have happened as the machine was operating for some time unloaded or in a light load condition as no coal transfers/air supply demand had occurred, they would have started around the time of the fire which was when that auto system was due to operate and top up the daily coal hopper.
There are no guarantees that inspecting the compressor after start up would have identified a system problem. However, the second engineer was not aware of the compressors operating state, or its loaded condition, because he did not inspect the compressor after it had been started.
On board emergency response River Embley’s muster list outlined the individual responsibilities of each of the crew members on board the ship and listed their muster station. It also contained an instruction that was to be followed when an automated fire alarm sounded.
On an auto alarm sounding, the alarm will be investigated and if necessary the emergency muster signal will be made. On hearing the emergency muster signal, all hands will muster at their allocated station. Lifejackets and protective clothing must be worn.
On 16 February 2010, the crew’s response to the emergency situation was carried out in accordance with this procedure. The source of the fire was investigated, the
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bridge watch keeper was notified that there was a fire in the engine room and the muster signal was activated a short time later.
On hearing the muster signal, the crew mustered as per the muster list. Apart from the third engineer closing the fire dampers on his own volition, the crew’s response was well organised, controlled and coordinated. They understood their roles and responsibilities, worked as a team and appropriately considered the evidence at hand when planning their response.
The master ensured that the crew were all accounted for and that preparations were made for a fire party entry into the engine room. At the same time, fire hoses were run out in case they were needed for boundary cooling. Then, when the engineers reported what they had experienced in the engine room, it was decided that entry into the space should be delayed. The crew were not required for an immediate response to the fire, so the master mustered them all on the bridge, where he considered that they would be safe and well informed of the actions that were being taken.
The master consulted with the chief engineer and the other senior officers and together, they decided to blackout the engine room. Since the amount of smoke coming from the skylight appeared to diminish after the explosion, they decided to leave the skylight open and monitor the situation. When it appeared that the smoke had cleared, they decided it was safe to enter the engine room. When they eventually re-entered the engine room, they carefully planned their action and then implemented that plan.
Together, the master and crew demonstrated how effective a trained response to an unexpected emergency can be.
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3 FINDINGS
3.1 Context On 16 February 2010, the Australian registered bulk carrier River Embley was at anchor off Gladstone, Queensland, when the ship’s fire alarms sounded, alerting the crew to an engine room fire. A few minutes later, while the engineers were investigating the fire, there was an explosion in the engine room.
The crew shut down the running machinery, the engine room ventilation dampers were closed and electrical power supply was transferred to the emergency generator. The crew continued to monitor the situation and by 1115, they had determined that the fire was extinguished.
From the evidence available, the following findings are made with respect to the engine room fire on board River Embley and should not be read as apportioning blame or liability to any particular organisation or individual.
3.2 Contributing safety factors • At about 0330 on 16 February 2010, River Embley’s number three coal transfer
compressor was started.
• It is likely that the compressor fluid cooling system thermostatic valve failed to operate correctly, causing the compressor fluid temperature to increase.
• The compressor did not automatically shut down when the temperature of the fluid reached the alarm/shutdown set point. As a result, the fluid temperature continued to increase, eventually reaching its flashpoint.
• It is likely that a fire started inside the compressor separator when the fluid was ignited by a hot spot or a spark generated within the compressor.
• The fire caused the pressure inside the separator to increase until its safety valve lifted, expelling large quantities of hot oil vapour into the engine room.
• The oil vapour in the engine room was ignited, either by an expulsion of flame from the safety valve or a hot metal surface on the compressor, resulting in a deflagration of the vapour cloud.
3.3 Other safety factors • The number three coal transfer compressor was not inspected to ensure that it
was operating satisfactorily after it was started.
• The compressor high temperature alarm/shutdown had not been routinely tested to ensure its correct operation.
• River Embley’s planned maintenance system did not require routine testing of the compressor high temperature alarm/shutdown. [Minor safety issue]
• The manufacturer’s maintenance manual requirements did not include routine testing of the compressor high temperature alarm/shutdown. [Minor safety issue]
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3.4 Other key findings • The crew’s response to the emergency situation was well organised, controlled
and coordinated, demonstrating how effective a trained/drilled response to an unexpected emergency can be.
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4 SAFETY ACTION
The safety issues identified during this investigation are listed in the Findings and Safety Actions sections of this report. The Australian Transport Safety Bureau (ATSB) expects that all safety issues identified by the investigation should be addressed by the relevant organisations. In addressing those issues, the ATSB prefers to encourage relevant organisations to proactively initiate safety action, rather than to issue formal safety recommendations or safety advisory notices.
All of the responsible organisations for the safety issues identified during this investigation were given a draft report and invited to provide submissions. As part of that process, each organisation was asked to communicate what safety actions, if any, they had carried out or were planning to carry out in relation to each safety issue relevant to their organisation..
4.1 ASP Ship Management
4.1.1 Planned maintenance system
Safety issue
River Embley’s planned maintenance system did not require routine testing of the number three coal transfer compressor alarm/shutdown.
Action taken by ASP Ship Management MO-2010-001-NSA-001
On 17 February, the day after the fire, ASP Ship Management advised all chief engineers in the fleet of the incident on board River Embley and instructed them to check the operation of each screw air compressor and to test all associated safety devices.
Subsequently, the planned maintenance schedules on board all ships in the fleet have been updated to include routine testing of compressor shutdown devices.
ATSB assessment of response
The ATSB is satisfied that the action taken by ASP Ship Management adequately addresses this safety issue.
4.2 Champion Compressors
4.2.1 Maintenance manual
Safety issue
The manufacturer’s maintenance manual did not include a requirement for the routine testing of the compressor alarm/shutdown.
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Response from Champion Compressors MO-2010-001-NSA-002
Champion Compressors acknowledges that a ship’s engineer is suitably qualified to carry out the various tasks involved in testing the shutdown systems on these types of compressors. However, the testing of this type of equipment has its challenges because of the varying skill levels of operators across our customer base.
Therefore, Champion Compressors have worked to design fail-safe protective systems. The new type temperature probe is a 4 - 20 mA transducer which is continually monitored by the compressor control system. The control system will immediately shut down the compressor if the probe fails.
Today’s compressors are also fitted with a secondary temperature probe. This acts as a further protection if the temperature rises above the set point of the primary shut down device. This probe is situated in the minimum pressure valve on top of the separator and it will shut the machine down when an increase in separator temperature occurs or there is a flash fire in the separator.
Today’s Champion Compressor manuals also state that compressor protective systems should be checked every 6000 hours.
The compressor fitted on board River Embley as a replacement for the Sullair compressor that was damaged in the fire is fitted with all the protection systems described above.
ATSB assessment of response
The ATSB is satisfied that the response from Champion Compressors adequately addresses this safety issue.
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APPENDIX A: EVENTS AND CONDITIONS
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APPENDIX B: SHIP INFORMATION
River Embley IMO number 8018144
Call sign VJRY
Flag Australia
Port of Registry Sydney
Classification society Lloyd’s Register (LR)
Ship Type Bulk carrier
Builder Mitsubishi Heavy Industries
Year built 1983
Owners Australian River Company
Ship managers ASP Ship Management
Gross tonnage 51,035
Net tonnage 16,346
Deadweight (summer) 76,358 tonnes
Summer draught 12.321 m
Length overall 255.00 m
Length between perpendiculars 248.01 m
Moulded breadth 35.35 m
Moulded depth 18.29 m
Engine Mitsubishi MS-21-2 steam turbine
Total power 13,976 kW
Service speed 14.5 knots
Crew 22
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APPENDIX C: SOURCES AND SUBMISSIONS
Sources of Information River Embley’s master and crew
ASP Ship Management
Champion Compressors
SKF Australia
References Strauch, Barry, Investigating Human Error, Ashgate, England 2004
Submissions Under Part 4, Division 2 (Investigation Reports), Section 26 of the Transport Safety Investigation Act 2003, the ATSB may provide a draft report, on a confidential basis, to any person whom the ATSB considers appropriate. Section 26 (1) (a) of the Act allows a person receiving a draft report to make submissions to the ATSB about the draft report.
A draft of this report was provided to River Embley’s master, chief engineer, first engineer, second engineer and engineer cadet, ASP Ship Management, SKF Australia, Champion Compressors and the Australian Maritime Safety Authority (AMSA).
Submissions were received from River Embley’s master, chief engineer, first engineer and second engineer, ASP Ship Management, SKF Australia, Champion Compressors and AMSA. The submissions were reviewed and where considered appropriate, the text of the report was amended accordingly.
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ATSB TRANSPORT SAFETY REPORTMarine Occurrence Investigation No. 272
MO-2010-001Final
Independent investigation into the engine room fire on board the Australian registered bulk carrier
River Embleyoff Gladstone, Queensland
16 February 2010
Independent investigation into the engine room
fire on board the
Australian registered bulk carrier R
iver Embley off G
ladstone, Queensland,
16 February 2010.
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