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Is you day worse than it was for this pilot?
Monday Accident & Lessons Learned: The US Chemical Safety Board Releases Bulletin on Anhydrous Ammonia Incident near Mobile, AlabamaJanuary 26th, 2015 by Mark Paradies
CSB Releases Safety Bulletin on Anhydrous Ammonia Incident near Mobile, Alabama
Safety Bulletin Notes Five Key Lessons to Prevent Hydraulic Shock
January 15, 2014, East Rutherford, NJ – Today the U.S. Chemical Safety Board released a safety bulletin intended to inform industries that utilize anhydrous ammonia in bulk refrigeration operations on how to avoid a hazard referred to as hydraulic shock. The safety lessons were derived from an investigation into a 2010 anhydrous ammonia release that occurred at Millard Refrigerated Services Inc., located in Theodore,
The accident occurred before 9:00 am on the morning of August 23, 2010. Two international ships were being loaded when the facility’s refrigeration system experienced “hydraulic shock” which is defined as a sudden, localized pressure surge in piping or equipment resulting from a rapid change in the velocity of a flowing liquid. The highest pressures often occur when vapor and liquid ammonia are present in a single line and are disturbed by a sudden change in volume.
This abnormal transient condition results in a sharp pressure rise with the potential to cause catastrophic failure of piping, valves, and other components – often prior to a hydraulic shock incident there is an audible “hammering” in refrigeration piping. The incident at Millard caused a roof-mounted 12-inch suction pipe to catastrophically fail, resulting in the release of more than 32,000 pounds of anhydrous ammonia.
The release led to one Millard employee sustaining injuries when he fell while attempting to escape from a crane was after it became engulfed in the traveling ammonia cloud. The large cloud traveled a quarter mile from the facility south toward an area where 800 contractors were working outdoors at a clean-up site for the Deepwater Horizon oil spill. A total of 152 offsite workers and ship crew members reported symptomatic illnesses from ammonia exposure. Thirty two of the offsite workers required hospitalization, four of them in an intensive care unit.
Chairperson Rafael Moure-Eraso said, “The CSB believes that if companies in the ammonia refrigeration industry follow the key lessons from its investigation into the accident at Millard Refrigeration Services, dangerous hydraulic shock events can be avoided – preventing injuries, environmental damage, and potential fatalities.”
Entitled, “Key Lessons for Preventing Hydraulic Shock in Industrial Refrigeration Systems” the bulletin describes that on the day before the incident, on August 22, 2010, the Millard facility experienced a loss of power that lasted over seven hours. During that time the refrigeration system was shut down. The next day the system regained power and was up and running, though operators reported some problems. While doing some troubleshooting an operator cleared alarms in the control system, which reset the refrigeration cycle on a group of freezer evaporators that were in the process of defrosting. The control system reset caused the freezer evaporator to switch directly from a step in the defrost cycle into refrigeration mode while the evaporator coil still contained hot, high-pressure gas.
The reset triggered a valve to open and low temperature liquid ammonia was fed back into all four evaporator coils before removing the hot ammonia gas. This resulted in both hot, high-pressure gas and extremely low temperature liquid ammonia to be present in the coils and associated piping at the same time. This caused the hot high-pressure ammonia gas to rapidly condense into a liquid. Because liquid ammonia takes up less volume than ammonia gas – a vacuum was created where the gas had been. The void sent a wave of liquid ammonia through the piping – causing the “hydraulic shock.”
The pressure surge ruptured the evaporator piping manifold inside one of the freezers and its associated 12-inch piping on the roof of the facility. An estimated 32,100 pounds of ammonia were released into the surrounding environment.
Investigator Lucy Tyler said, “The CSB notes that one key lesson is to avoid the manual interruption of evaporators in defrost and ensure control systems are equipped with password protection to ensure only trained and authorized personnel have the authority to manually override systems.“
The CSB also found that the evaporators at the Millard facility were designed so that one set of valves controlled four separate evaporator coils. As a result, the contents of all four coils connected to that valve group were involved in the hydraulic shock event – leading to a larger, more hazardous pressure surge.
As a result, the CSB notes that when designing ammonia refrigeration systems each evaporator coil should be controlled by a separate set of valves.
The CSB found that immediately after discovering the ammonia release, a decision was made to isolate the source of the leak while the refrigeration system was still operating instead of initiating an emergency shutdown. Shutting down the refrigeration system may have resulted in a smaller release, since all other ammonia-containing equipment associated with the failed rooftop piping continued to operate.
A final key lesson from the CSB’s investigation is that an emergency shutdown should be activated in the event of an ammonia release if a leak cannot be promptly isolated and controlled. Doing so can greatly reduce the amount of ammonia released during an accident.
Linda Unger, VP at SI, sent these pictures of Ken Turnbull, one of our contract instructors, teaching a bunch of great students.
Thank you to Derek Rutherford for sharing these photos with us from a recent Onsite course at Cape Industries.
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It’s easy for a CEO and management to claim to support safety. But the proof comes when times get tough.
The price of oil has declined more that 50% in just six months. That has the oil field in crisis mode. Knee jerk budget cuts, travel restrictions, and layoffs have already started.
What does this mean to safety improvement? Many oil industry safety professionals get ideas about ways to improve by attending the TapRooT® Summit, networking with industry leaders and performance improvement experts, hearing about the latest best practices that will help them solve their toughest problems, and developing plans to take safety to a whole new and better level. But if travel budgets are slashed and conferences are not allowed, these new best practices won’t be learned, safety improvement will stop, and lives that could have been saved will be lost.
Now is the time for management to show their commitment to safety improvement. They can stand up, resist the fear of low oil prices, and demand that safety improvement continues even in times of budget restraint.
After all, safety is not just a priority that can be discarded when times get tough. Safety is a value that must be supported every day, year in and year out, in good times and bad, or people will start to believe that safety is option and the only real value is profit.
Don’t let safety improvement become an unsupported slogan. Register for the TapRooT® Summit today!
Just like this if you own a Subway …
TapRooT® hosts public courses all over the world, including New Zealand. Come out to New Plymouth, New Zealand on February 16, 2015 for a 5-Day Advanced Root Cause Analysis Team Leader Training to learn how you can be proactive and perform better investigations. New Plymouth is a coastal city on the west coast of New Zealand that has been named a “model community” because of its beautiful infrastructure. The small population walks and cycles along the coastal walkway (pictured above) and enjoys the each other’s company and the view. Talk about a great place to visit and take a TapRooT® course!
Table Restaurant: Placed within the Nice Hotel, this gourmet, award winning restaurant ensures you will enjoy food, wine and friends.
The Mayfair: Want a burger, fries, salads, pizzas or snacks? The Mayfair has it all and some drinks to go with it.
Cow Ree: This small vintage cottage set right on the beach makes for a fun, enjoyable evening out for a great meal.
Pukekura Park: You’ve never experienced a local park with such beautiful scenery and events-including a lights show you won’t forget!
Coastal Walkway: Enjoy a nice walk along the coast with a perfect view of the mountains.
Taranaki Aviation Transport and Technology Museum: If you’re interested in all things to do with aviation and technological transportation, then this museum is for you.
REGISTER HERE for this Public Course today
Monday Accident & Lessons Learned: UK RAIB Report – Near-miss involving construction workers at Heathrow Tunnel Junction, west London, 28 December 2014January 19th, 2015 by Mark Paradies
UK Rail Accident Investigation Branch Press Release…
The UK RAIB is investigating an incident in which a train almost struck two construction workers, and collided with a small trolley, on the Up Airport line between Heathrow Airport Tunnel and the Stockley Flyover.
Yellow engineering trolley underneath the train after the collision (image courtesy of Carillion)
The incident occurred at about 10:05 hrs on Sunday 28 December 2014 and involved train 1Y40, the 09:48 hrs service from London Heathrow Terminal 5 to London Paddington. The track workers jumped clear just before the approaching train struck a small engineering trolley that they had been placing on the line. The train, formed by a Class 332 electric multiple unit, was travelling at approximately 36 mph (58 km/h) when it struck the trolley.
The two track workers were among a large number of people carrying out construction work on the approach to a new bridge that had been recently constructed adjacent to the existing Stockley Flyover. This new structure, which carries a new railway track over the mainline from London Paddington to Reading, was built as part of the Crossrail surface works being undertaken by Network Rail.
To enable this work to take place, parts of the operational railway in and around the construction site had been closed for varying periods during the few days before the incident. The two construction workers were unaware that the Up Airport line had returned to operational use a few hours before they started to place the trolley onto this line. They formed part of an eight person workgroup which included a Controller of Site Safety (COSS). The COSS and other group members were not with the two track workers at the time of the incident. The presence of temporary fencing, intended to provide a barrier between construction activities and the operational railway, did not prevent the two track workers accessing the open line.
Network Rail owned the infrastructure at the site of the accident and had employed Carillion Construction as the Principal Contractor for the construction works. The two track workers and the COSS were all employed by sub-contractors.
RAIB’s investigation will establish the sequence of events, examine how the work was planned, how the staff involved were being managed and the way in which railway safety rules are applied on large construction sites adjacent to the operational railway. It will also seek to understand the actions of the people involved, and factors that may have influenced their behaviour.
RAIB will also consider whether there is any overlap between this incident and the factors which resulted in an irregular dangerous occurrence at the same construction site on the previous day. This occurrence involved a gang of railway workers who walked along a line that was open to traffic, and without any form of protection, until other construction workers warned them that the line was open to traffic.
The RAIB investigation is independent of any investigations by the safety authority or the police. RAIB will publish its findings at the conclusion of the investigation. This report will be available on the RAIB website.
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What can we learn BEFORE the investigation is complete?
First, this “near-miss” was actually a hit.
In this case it was called a near-miss because no one was injured. However, the train and trolley were damaged and work was delayed. For operations, maintenance, and construction, this was an incident. In other words, it was a safety near-miss but it was an operation, maintenance, and construction hit.
Many incidents that don’t have immediate safety consequences do have immediate cost, productivity, and reliability consequences that are worthy of an investigation. And in this case, the operations incident also had potential to become a fatality. This even more reason to perform a thorough root cause analysis.
Thank you to Reb Brickey from Chinese General Nuclear Power for taking a few pictures of a recent Onsite course in Schenzhen, China.
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UK RAIB Press Release: Investigating tram derailment near Mitcham Junction, London, 29 December 2014January 12th, 2015 by Mark Paradies
At about 23:55 hrs on Monday 29 December 2014, a tram travelling from New Addington to Wimbledon on the Croydon Tramlink system became derailed shortly after leaving the tram stop at Mitcham Junction, while travelling at about 11 km/h (7 mph). There were about 20 passengers, plus the driver, on board the tram, and no-one was hurt. There was some minor damage to the tram.
To the west of Mitcham Junction tram stop, the single tram line becomes two lines at a set of spring-operated points. On leaving the tram stop, the tram driver noticed that an indicator, which shows the position of these points, was indicating that the points were not correctly set. He stopped the tram before reaching the points, and after speaking to the tramway control room by radio, he left the tram and used an operating lever to manually move the points until he observed that the indicator was showing that they were correctly set. He then drove the tram slowly over the points, but the centre bogie and one wheelset of the trailing bogie became derailed.
Image showing derailed tram near Mitcham Junction
RAIB’s investigation will focus on the points mechanism and the way that it behaves in degraded operating conditions.
RAIB’s investigation is independent of any investigation by the railway industry or the Office of Rail Regulation.
The UK RAIB will publish their findings, including any recommendations to improve safety, at the conclusion of its investigation. This report will be available at http://www.raib.gov.uk.
Monday Accident & Lessons Learned: UK RAIB Investigations of an unauthorised entry of a train onto a single line at GreenfordJanuary 12th, 2015 by Mark Paradies
Unauthorised entry of a train onto a single line at Greenford
20 March 2014
From the UK Rail Accident Investigation Branch:
At around 11:55 hrs on Thursday 20 March 2014, the 11:36 hrs passenger train from London Paddington to West Ruislip, operated by Chiltern Railways, passed two consecutive signals at danger near Greenford, west London. It was stopped when a signaller sent an emergency radio message to the driver. Although no-one was hurt in the incident, the unauthorised entry of a train onto a single line creates the potential for a serious collision.
A freight train had passed the junction at Greenford shortly before the passenger train was due. Because the freight train was still occupying the line between Greenford and South Ruislip, the signaller at Greenford kept the signal at the junction at danger. The passenger train, travelling at about 20 mph (32 km/h), passed this signal and the next one, 142 yards (130 metres) further on, which was also at danger. It passed over the junction and onto the single-track section towards South Ruislip, which was still occupied by the freight train. The train had travelled about one mile (1.6 km) beyond Greenford by the time that the driver received the emergency radio message.
The investigation found that the driver of the passenger train did not react to the two signals at danger, for reasons which are not certain. It is possible that he had formed the impression that the train had been given clear signals through Greenford, because of his interpretation of the meaning of the signal preceding those that he passed at danger, and he had not been stopped by signals at Greenford in the recent past.
The Train Protection and Warning System (TPWS) was fitted to the train and to both the signals, but it did not intervene to apply the brakes of the train, as it was intended to do. This was because the on-train TPWS equipment had self-isolated when the driver prepared the train for departure from Paddington. The isolation of the equipment was indicated by a flashing light in the cab, but the driver still drove the train.
Although the signaller at Greenford wished to stop the train by sending an emergency call on the GSM-R radio system, he did not attempt to do so because the information presented by the radio equipment in the signal box suggested to him that any message he sent would not reach the train. Instead, he contacted Marylebone signal box, which was able to send a message to the train.
RAIB has made three recommendations. One is addressed to Chiltern Railways, and covers the need for a review of the company’s driver management processes. The other two, addressed to Network Rail, cover the configuration of the GSM-R radio system as it affects the ability of signallers to directly contact trains that are within their areas of control, and the training given to signallers in the use of the GSM-R system. RAIB has also identified two learning points: one for signallers, relating to the use of delayed clearance of signals to warn train drivers of the state of the line ahead, and the other for train operating companies, relating to the upgrading of on-train TPWS equipment.
To see the complete report and all recommendations, see:
One of the main complaints I hear is that management doesn’t provide enough support for performance improvement programs, accident/incident investigations, and root cause analysis.
One thing I’ve learned is that if senior management really cares, the rest of management will usually fall in line (or get fired).
That brings me to these questions …
Does your CEO care about performance improvement,
incident investigation, and root cause analysis?
Should they care?
Now for the answer…
An oil company had a fire on an offshore production platform. The fire knocked out a significant portion of the company’s gas production right in the middle of the heating season. The incident was mentioned on the front page of The Wall Street Journal because it would impact the company’s quarterly earnings.
What do you think? Did the CEO care?
How about the CEO at BP or Transocean when the Deepwater Horizon exploded, burned, and sank? Do you think they cared?
Or the CEO of Dixie Crystals when the factory in Savannah, GA, blew up?
Or the CEO at GM when she was called to testify in front of Congress about ignition switch problems that resulted in fatal auto accidents?
These are examples of CEO’s that definitely cared AFTER THE FACT. They wished someone had stood up before the accidents and stopped the problems before they reached the CEO’s attention. And they all claimed to have no advance knowledge of the problems that lead to the accidents.
Therefore, the CEO should care and it may be your job to prevent the accidents that could happen so that your CEO never knows that they should care. Never has to appear in front of cameras and say that s/he is sorry. Never has to face a mad Congressional committee.
Perhaps you occasionally need to remind people how important it is to investigate small problems with the potential to become big problems and effectively fix the issues so that the CEO never hears about your facility.
That’s when you can explain why using the best advanced root cause analysis technique (TapRooT®) is so important and why senior management should be interested in ensuring that the company’s performance improvement program is best-in-class.
Thank you to Camila Sierra for providing these wonderful pictures of some recent Public TapRooT® Courses in Bogota, Colombia.
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