Tag Archives: rail

Root Cause Analysis - Incident Investigation

Freight Train Carrying Crude Oil Explodes After Colliding With Another

By Kim Smiley

On Monday, December 30, 2013, a 106-car freight train carrying crude oil derailed in North Dakota and violently exploded after colliding with another derailed train that was on the tracks.  No injuries were reported, but the accident did cause an impressive plume of hazardous smoke and major damage to two freight trains.

The investigation into the accident is ongoing and it’s still unknown what caused the first train to derail. Investigators have stated that it appears that there was nothing wrong with the railroad track or with the signals.  It is known that a westbound freight train carrying grain derailed about 2:20 pm.  A portion of this train jumped onto the track in front of the eastbound train.  There wasn’t enough time for the mile long train loaded with crude oil to stop and it smashed into the grain train, causing the eastbound oil train to derail.  (To see a Cause Map of this accident, click on “Download PDF” above.)

Train cars carrying crude oil were damaged and oil leaked out during the accident.  The train accident created near ideal conditions for an explosion: sparks and a large quantity of flammable fluid.   The fire burned for more than 24 hours, resulting in a voluntary evacuation of nearby Casselton, North Dakota due to concerns over air quality.  The track was closed for several days while the initial investigation was performed and the track was cleaned up.

The accident has raised several important issues.  The safety of the train cars used to transport oil has been questioned.  Starting in 2009, tank train cars have been built to tougher safety standards, but most tank cars in use are older designs that haven’t been retrofitted to meet the more stringent standards.  This accident, and others that have involved the older design tank cars in recent year, have experts asking hard questions about their safety and whether they should still be in use.

The age of the train cars is particularly concerning since the amount of oil being transported by rail has significantly expanded in result years.  Around 9,500 carloads of oil were reportedly transported in 2008 and nearly 300,000 carloads were moved during the first three quarters of 2013.  The oil industry in North Dakota has rapidly expanded in recent years as new technology makes oil extraction in the area profitable.   North Dakota is now second only to Texas in oil production since the development of the Bakken shale formation.  Pretty much the only way to transport the crude oil extracted in North Dakota is via rail.  There isn’t a pipeline infrastructure or other alternative available.

And most of the time, transporting oil via freight train is a safe evolution.  The Association of American Railroads has reported that 99.99 percent of all hazardous materials shipped by rail reach the destination safely.  But it’s that 0.01 percent that can get you in trouble.  As a nation, we have to decide if where we are at is good enough or if it’s worth the money to require all tank cars used to transport oil to be retrofitted to meet the newest safety standards, a proposition that isn’t cheap.

Root Cause Analysis - Incident Investigation

“Ghost Train” Causes Head-On Collision in Chicago

By Kim Smiley

On September 30, 2013, an unoccupied train collided head on with another train sending 30 people to the hospital in Chicago.  In a nod to the season and the bizarre circumstances of the accident, the unoccupied train has been colorfully dubbed “the ghost train”. 

So what caused the “ghost train” and how did it end up causing a dangerous train collision?  Investigators from the National Transportation Safety Board (NTSB) are still reviewing the details of the accident, but some information is available.  An initial Cause Map, or visual root cause analysis, can be built to capture what is already known and can be expanded to incorporate more information as the investigation progresses.  A Cause Map is built by asking “why” questions and documenting the answers to visually lay out all the causes that contributed to an accident to show the cause-and-effect relationships from left to right.

In this example, the trains collided because an unoccupied train began moving and the safety systems in place did not stop the train.  Investigators still haven’t determined exactly what caused the train cars to move, but a key piece of the puzzle is that there was still power to the cars while they were being stored in a repair terminal awaiting maintenance.  The NTSB believes that it was common practice to leave power to cars so that the lights could be used to illuminate the terminal.  Workers used the lights to discourage graffiti and vandalism because the terminal was located in a high crime neighborhood. 

Investigators will need to not only determine why the train started rolling, but also learn more about why the safety systems didn’t prevent the accident.  Before colliding with another train, the unoccupied train traveled through five mechanical train-stop mechanisms, each of which should have stopped a train without a driver.  Emergency brakes were applied at each train-stop that caused the train to pause momentarily, but then it started moving because the setting on the master lever caused the train to restart.  Review of the safety systems will need to be part of the investigation to ensure that adequate protection is in place to prevent anything similar from occurring again.

The NTSB investigation is still ongoing, but the NTSB has stated that de-energizing propulsion power and using an alternate brake setting could help prevent unintended movement of unoccupied train cars. Additionally, the NTSB believes the use of a wheel chock and/or derail would ensure that a train stopped by a mechanical train stop mechanism remains stopped.  Based on the information already uncovered, the NTSB has issued an urgent safety recommendation to the Federal Transit Authority (FTA). The NTSB recommended that the FTA issue a safety advisory to all rail transit properties to review procedures for storing unoccupied train cars to ensure that they were left in a safe condition that wouldn’t allow unintended movement and to ensure that they had redundant means of stopping any unintended movement.  There is more information that is needed to fully understand this accident, but these precautions would be effective solutions that can be quickly implemented to reduce the risk of train accidents.

Root Cause Analysis - Incident Investigation

Train Crash in China Kills 39

By Kim Smiley

It is rare for the conduct of the investigation to be one of the biggest headlines in the week following an accident, but this has been the case after a recent train crash in China.  On July 23, 2011, two trains collided in Wenzhou, China, killing 39 and sending another 192 people to the hospital.

What appears to have happened is that a train moving at speed rear ended another train that had stalled on the tracks. It was announced that the first train had stalled after a lightning strike.  Soon after the accident, people reported seeing the damaged train cars broken apart by back hoes and buried.  Meaning the evidence was literally being buried without ever having been thoroughly examined.  The Chinese government stated that the cars contained “State-level” technology and were being buried to keep it safe.

The internet frenzy and public outrage fueled by how this investigation was handled was impressive. According to a recent New York Times article, 26 million messages about the tragedy have been posted on China’s popular twitter-like microblogs.  So powerful has the public outrage been that the first car from the oncoming train has been dug up and sent to Wenzhou for analysis.

More information  on the technical reasons for the train crash is slowly coming to light.  Five days after the accident, government officials have stated that a signal which would have stopped the moving train failed to turn red and the error wasn’t noticed by workers.  There is talk about system design errors and inadequate training.

It’s unlikely that all the details will ever be public knowledge, but there is one takeaway from this accident that can be applied to any organization in any industry that performs investigations – the importance of transparency. The Chinese government spent over $100 billion in 2010 expanding the high speed rail system, but if people don’t feel safe riding the rail system it won’t be money well spent.  Customers need to feel that an adequate investigation has been performed following an accident or they won’t use the products produced by the company.

To view an initial Cause Map built for this train accident, please click on “Download PDF” above.  A Cause Map is an intuitive, visual method of performing a root cause analysis.  One of the benefits of a Cause Map is that it’s easily understood and can help improve the transparency of an investigation for all involved.