Tag Archives: rail

Root Cause Analysis - Incident Investigation

Train Derails on Track Just Inspected

By ThinkReliability Staff

A train derailment in the Columbia River Gorge near Mosier, Oregon resulted in a fire that burned for 14 hours. The Federal Railroad Administration (FRA) preliminary investigation says the June 3rd derailment was caused by a broken lag bolt which allowed the track to spread, resulting in the 16-car derailment. Although there is only one other known instance of a broken lag bolt causing a train derailment, the FRA determined that the bolt had been damaged for some time, and had been inspected within days of the incident, raising questions about the effectiveness of these inspections.

Determining all the causes of a complex issue such as a train derailment can be difficult, but doing so will provide the widest selection of possible solutions. A Cause Map, or visual root cause analysis, addresses all aspects of the issue by developing cause-and-effect relationships for all the causes based on the impacts to an organization’s goals. We can create a Cause Map based on the preliminary investigation. Additional causes and evidence can be added to the map as more detail is known.

The first step in the Cause Mapping process is to determine the impacts to the organization’s goals. While there were no injuries in this case, the massive fire resulting from the derailment posed a significant risk to responders and nearby citizens, an impact to the safety goal. The release of 42,000 gallons of oil (although much of it was burned off in the fire) is an impact to the environmental goal. The customer service goal is impacted by the evacuation of at least 50 homes and the regulatory goal is impacted by the potential for penalties, although the National Transportation Safety Board (NTSB) has said it will not investigate the incident. The state of Oregon has requested a halt on oil traffic, which would be an impact to the schedule goal. The property goal is impacted by the damage to the train cars, and the labor/ time goal is impacted by the response and investigation.

The analysis, which is the second step in the Cause Mapping process, begins with one of the impacted goals and develops cause-and-effect relationships by asking ‘Why’ questions. In this case, the safety goal is impacted by the high potential for injuries. This is caused by the massive fire, which burned for 14 hours. There may be more than one cause resulting in an effect, such as a fire, which is caused by heat, fuel, and oxygen. The oxygen in this case is from the atmosphere. The heat source is unknown but could have been a spark caused by the train derailment. The fire was fueled by the 42,000 gallons of crude released due to damage to train cars, which were transporting crude from the Bakken oil fields, caused by the derailment.

The derailment of 16 cars of the train was caused by the broken lag bolt. Any mechanical failure, such as a break, results from the stress on that object exceeding the strength of the object. In this case, the stress was caused by the weight of the 94-car train. The length of a train carrying crude oil is not limited by federal regulations. The strength of the bolts was reduced due to previous damage, which was not identified prior to the failure. While the track strength is evaluated every 18 months by the Gauge Restraint Measurement System (GRMS), it did not identify the damage. It’s unclear the last time it was performed.

Additionally, although the track is visually inspected twice a week by the railroad, it is done by vehicle, which would have made the damage harder to spot. The FRA does not require walking inspections. Nor does the FRA inspect or review the railroad’s inspections very often – there are less than 100 inspectors for the 140,000 miles of track across the country. There are only 3 in Oregon.

As a result of the derailment, the railroad has committed to replacing the existing bolts with heavy-duty ones, performing GRMS four times a year, enhanced hyrail inspections and visual track inspections three times a week, and performing walking inspections on lag curves monthly.

The FRA is still evaluating actions against the railroad and is again calling for the installation of advanced electronic brakes, or positive train control (PTC). It has also recommended PTC after other incidents, such as the deaths of two railroad workers on April 3 (see our previous blog) and the derailment in Philadelphia last year that killed 8 (see our previous blog).

To view a one-page PDF of the Cause Mapping investigation, click on “Download PDF” above. Or, click here to read the FRA’s preliminary investigation.

Root Cause Analysis - Incident Investigation

DC Metro shut down for entire day after fire for inspections

By Kim Smiley 

A fire in a DC Metro tunnel early on March 14, 2016 caused delays on three subway lines and significant disruption to both the morning and evening commutes.  There were no injuries, but the similarities between this incident and the deadly smoke incident on January 12, 2015 (see our previous blog on this incident) led officials to order a 24-hour shutdown of the entire Metro system for inspections and repairs.

The investigation into the Metro fire is still ongoing, but the information that is known can be used to build an initial Cause Map.  A Cause Map is built by asking “why” questions and visually laying out all the causes that contributed to an incident.  Cause Mapping an issue can identify areas where it may be useful to dig into more detail to fully understand a problem and can help develop effective solutions.

So why was there a fire in the Metro tunnel?  Investigators have not released details about the exact cause, but have stated that the fire was caused by issues with a jumper cable.  Jumper cables are used in the Metro system to bridge gaps in the third rail, essentially functioning as extension cords.  The Metro system uses gaps in the third rail to create safer entry and exit spaces for both workers and passengers because of the potential danger of contact with the electrified third rail.  The third rail carries 750 volts of electricity used to power Metro trains and could cause serious injury or even death if accidently touched.

The jumper cables also carry high voltage and fires and/or smoke can occur if one malfunctions.  Investigators have not confirmed the exact issue that lead to this fire, but insulation failures have been identified in other locations and is a possible cause of the fire. (Possible causes can be added to the Cause Map with a “?” to indicate that more evidence is needed.)

One of the things that is always important to consider when investigating an incident is the frequency of occurrence of similar issues.  The scope of the investigation and possible solutions considered will likely be different if it was the 20th time an incident has occurred rather than the first. In this case, the fire was similar to another incident in January 2015 that caused a passenger death.  Having a second incident occur so soon after the first naturally raised questions about whether there were more unidentified issues with jumper cables.  The Metro system uses approximately 600 jumper cables and all were inspected during the day-long shutdown. Twenty-six issues were identified and repaired. Three locations had damage severe enough that Metro would have immediately stopped running trains through them if the extent of the damage had been known.

The General Manger of the DC Metro system, Paul J. Wiedefeld, is relatively new to his position and has been both praised and criticized for the shutdown.  Trying to implement solutions and reduce risk is always a balancing act between costs and benefits.  Was the cost of a full-day shutdown and inspections of all jumper cables worth the benefit of knowing that the cable jumpers have all been inspected and repaired?  At the end of the day, it’s a judgement call, but I personally would be more comfortable riding the Metro with my children now.

Root Cause Analysis - Incident Investigation

Investigators Blame “Human Error” for Train Collision

By Kim Smiley

On February 9, 2016, two commuter trains collided head-on in Upper Bavaria, Germany.  Eleven people were killed and dozens were injured.  Investigators are still working to determine exactly what caused the accident and the train dispatcher is currently under investigation for involuntary manslaughter and could face up to five years in prison if convicted.

Although the investigation is still ongoing, some information has been released about what caused the crash.  The two trains collided head-on because they were both traveling on the same track toward each other in opposite directions.  Running two trains on the same track is common practice in rural regions in Germany and these two trains were scheduled to pass each other at a station with a divided track. The drivers of both trains were unaware of the other train.  The accident occurred on a bend in a wooded area so the drivers could not see the other train until it was too late to prevent the collision.

The dispatcher failed to prevent a situation where two trains were running towards each other on the same track or to inform the drivers about the potential for a collision.  Investigators have stated that the dispatcher sent an incorrect signal to one of the trains due to “human error”.  After realizing the mistake – and that a collision was imminent – the dispatcher issued emergency signals to the trains, but they were too late to prevent the accident.

All rail routes in Germany have automatic braking systems that are intended to stop a train before a collision can occur, but initial reports are that the safety system had been manually turned off by the dispatcher.  German media has reported that the system was overridden to allow the eastbound train to pass because it was running late, but this information has not been confirmed.  Black boxes from both trains have been collected and analyzed.  Technical failure of the trains and signaling equipment have been ruled out as potential causes of the accident.

The information that has been released to the media can be used to build an initial Cause Map, a visual root cause analysis, of this issue.  A Cause Map visually lays out the cause-and-effect relationships and aids in understanding the many causes that contributed to an issue. The Cause Map is built by asking “why” questions. A detailed Cause Map can aid in the development of more effective solutions.

One of the general Cause Mapping rules of thumb is that an investigation should not stop at “human error”.  Human error is too general and vague to be helpful in developing effective solutions. It is important to ask “why” the error was made and really work to understand what factors lead to the mistake.  Should the safety system be able to be manually overridden?  Is the training for dispatchers adequate?  Does there need to be a second check on decisions by dispatchers?  Should two trains traveling in opposite directions be sharing tracks?  I don’t know the answers, but these questions should be asked during the investigation.  Charging the dispatcher with involuntary manslaughter may prevent HIM from making the same mistake again, but it won’t necessarily reduce the risk of a similar accident occurring again in the future.  To really reduce risk, investigators need to dig into the details of why the error was made.

Root Cause Analysis - Incident Investigation

Deadly Train Derailment Near Philadelphia

By Kim Smiley

On the evening of May 12, 2015, an Amtrak train derailed near Philadelphia, killing 8 and injuring more than 200.  The investigation is still ongoing with significant information about the accident still unknown, but changes are already being implemented to help reduce the risk of future rail accidents and improve investigations.

Data collected from the train’s onboard event recorder shows that the train sped up in the moments before the accident until it was traveling 106 mph in a 50 mph zone where the train track curved.  The excessive speed clearly played a role in the accident, but there has been little information released about why the train was traveling so fast going into a curve.  The engineer controlling the train suffered a head injury during the accident and has stated that he has no recollection of the accident. The engineer was familiar with the route and appears to have had all required training and qualifications.

As a result of this accident and the difficulty determining exactly what happened, Amtrak has announced that cameras will be installed inside locomotives to record the actions of engineers.  While the cameras may not directly reduce the risk of future accidents, the recorded data will help future investigations be more accurate and timely.

The excessive speed at the time of the accident is also fueling the ongoing debate about how trains should be controlled and the implementation of positive train control (PTC) systems that can automatically reduce speed.  There was no PTC system in place at the curve in the northbound direction where the derailment occurred and experts have speculated that one would have prevented the accident. In 2008, Congress mandated nationwide installation and operation of positive train control systems by 2015.  Prior to the recent accident, the Association of America Railroads stated that more than 80 percent of the track covered by the mandate will not have functional PTC systems by the deadline. The installation of PTC systems requires a large commitment of funds and resources as well as communication bandwidth that has been difficult to secure in some area and some think the end of year deadline is unrealistic. Congress is currently considering two different bills that would address some of the issues.  The recent deadly crash is sure to be front and center in their debates.

In response to the recent accident, the Federal Railroad Administration ordered Amtrak to submit plans for PTC systems at all curves where the speed limit is 20 mph less than the track leading to the curve for the main Northeast Corridor (running between Washington, D.C. and Boston).  Only time will tell how quickly positive train control systems will be implemented on the Northeast Corridor as well as the rest of the nation, and the debate on the best course of action will not be a simple one.

An initial Cause Map, a visual root cause analysis, can be created to capture the information that is known at this time.  Additional information can easily be incorporated into the Cause Map as it becomes available.  To view a high level initial Cause Map of this accident, click on “Download PDF”.

Root Cause Analysis - Incident Investigation

New Regulations Aim to Reduce Railroad Crude Oil Spills

By ThinkReliability Staff

The tragic train derailment in Lac-Mégantic, Quebec on July 6, 2013 (see our previous blog on this topic) ushered in new concerns about the transport of crude oil by rail in the US and Canada. Unfortunately, the increased attention has highlighted a growing problem: spills of crude oil transported via rail, which can result in fires, explosions, evacuations, and potentially deaths. (Luckily there have been no fatalities since the Lac-Mégantic derailment.) According to Steve Curwood of Living on Earth, “With pipelines at capacity the boom has lead a 4,000 percent increase in the volume of crude oil that travels by rail, and that brought more accidents and more oil spills in 2014 than over the previous 38 years.”

This follows a period of increases in railroad safety – according to the US Congressional Research Service, “From 1980 to 2012, railroads reduced the number of accidents releasing hazmat product per 100,000 hazmat carloads from 14 to 1.” From October 19, 2013 to May 6, 2015, there were at least 12 railcar derailments that resulted in crude oil spills. (To see the list of events, click on “Download PDF” and go to the second page.)

Says Sarah Feinberg, acting administrator of the Federal Railroad Administration (FRA), “There will not be a silver bullet for solving this problem. This situation calls for an all-of-the-above approach – one that addresses the product itself, the tank car it is being carried in, and the way the train is being operated.” All of these potential risk-reducing solutions are addressed by the final rule released by the FRA on May 1, 2015. (On the same day, the Canadian Ministry of Transport released similar rules.) In order to view how the various requirements covered by the rule impact the risk to the public as a result of crude oil spills from railcars, we can diagram the cause-and-effect relationships that lead to the risk, and include the solutions directly over the cause they control. (To view the Cause Map, or visual root cause analysis, of crude oil train car derailments, click on “Download PDF”.)

The product: Bakken crude oil (as well as bitumen) can be more volatile than other types of crude oil and has been implicated in many of the recent oil fires and explosions. In addition to being more volatile, the composition (and thus volatility) can vary. If a material is not properly sampled and characterized, proper precautions may not be taken. The May 1 rule incorporates a more comprehensive sampling and testing program to ensure the properties of unrefined petroleum-based products are known and provided to the DOT upon request.   (Note that in the May 6, 2015 derailment and fire in Heimdahl, North Dakota, the oil had been treated to reduce its volatility, so this clearly isn’t an end-all answer.)

The tank car: Older tank cars (known as DOT-111s) were involved in the Lac-Mégantic and other 2013 crude oil fires. An upgrade to these cars, known as CPC-1232, hoped to reduce these accidents. However, CPC-1232 cars have been involved in all of the issues since 2013. According to Cynthia Quarterman, former director of the Pipeline and Hazardous Materials Safety Administration, says that the recent accidents involving the newer tank cars “confirm that the CPC-1232 just doesn’t cut it.”

The new FRA rule establishes requirements for any “high-hazard flammable train” (HHFT) transported over the US rail network. A HHFT is a train comprised of 20 or more loaded tank cars of a Class 3 flammable liquid (which includes crude oil and ethanol) in a continuous block or 35 or more loaded tank cars of a Class 3 flammable liquid across the entire train. Tank cars used in HHFTs constructed after October 1, 2015 are required to meet DOT-117 design criteria, and existing cars must be retrofitted based on a risk-based schedule.

The way the train is being operated: The way the train is being operated includes not only the mechanics of operating the train, but also the route the train takes and the notifications required along the way. Because the risk for injuries and fatalities increases as the population density increases, the rule includes requirements to perform an analysis to determine the best route for a train. Notification of affected jurisdictions is also required.

Trains carrying crude oil tend to be very large (sometimes exceeding one mile in length). This can impact stopping distance as well as increase the risk of derailment if sudden stopping is required. To reduce these risks, HHFTs are restricted to 50 mph in all areas, and 40 mph in certain circumstances based on risk (one of the criteria is urban vs. rural areas). HHFTs are also required to have in place a functioning two-way end of train or distributed power braking system. Advanced braking systems are required for trains including 70 or more loaded tank cars containing Class 3 flammable liquids and traveling at speeds greater than 30 mph, though this requirement will be phased in over decades.

It is important to note that this new rule does not address inspections of rails and tank cars. According to a study of derailments from 2001 to 2010, track problems were the most important causes of derailments (with broken rails or track welds accounting for 23% of total cars derailed). A final rule issued January 24, 2014 required railroads to achieve a specified track failure rate and to prioritize remedial action.

To view the May 1 rule regarding updates to crude-by-rail requirements, click here. To view the timeline of incidents and the Cause Map showing the cause-and-effect relationships leading to these incidents, click “Download PDF”.

Root Cause Analysis - Incident Investigation

Train Derails in West Virginia

By Kim Smiley

On February 16, 2015, a train hauling 109 tank cars of crude oil derailed in Mount Carbon, West Virginia.  It has been reported that 27 tank cars in the train derailed.  Some of the tank cars were damaged and released an unknown amount of crude oil, resulting in a large fire.  Hundreds of families in the surrounding area were evacuated, but only one injury was reported.

The accident investigation is still ongoing, but what information is known can be used to build an initial Cause Map, a visual format for performing a root cause analysis.  The Cause Map can be easily expanded as needed to document additional information as it becomes available.

The first step in the Cause Mapping process is to fill in an Outline with the basic background information for the issue as well as how the overall goals were impacted. In this example, there were many impacted goals.  The safety goal is impacted because there was an injury, the property goal is impacted because of the damage to the train, the environmental goal is impacted because of the release of oil, etc.  Once the Outline is complete, the Cause Map itself is built by starting with an impact to a goal, asking “why” questions, and laying out all the causes that contributed to an issue.

The significant aftermath of this derailment is known, but little has been released about what specifically caused the train to derail.  It was snowing heavily at the time of the accident, which may have played a role, but since more evidence is needed, a “?” is included on the Cause Map.  Data from the digital data recorder has shown that the train was not speeding at the time of the accident, which has been a factor in previous derailments.  Another fact worth noting is that the damaged train cars were a newer design that incorporated modern safety upgrades.

With so many unknowns, the Federal Railroad Administration is conducting a full-scale investigation to determine exactly what happened.  The damaged tank cars, track, and other components along with relevant maintenance and inspection records will be all be analyzed to better understand this derailment.

Unfortunately, crude oil train accidents are predicted to become increasingly common as the volume of flammable liquids being transported by rail continues to rise.  According to the Association of American Railroad, 40 times more oil was transported by rail in 2012 than in 2008. Hopefully, the lessons learned from this derailment can be used to help reduce the risk of future rail accidents.

To view the Outline and initial Cause Map for this accident, click on “Download PDF” above.

Root Cause Analysis - Incident Investigation

Deadly Train-Car Collision

By Kim Smiley

On February 3, 2015, an SUV was struck by a commuter train near Valhalla, New York.  The driver of the vehicle and 5 train passengers were killed in the accident.  The National Transportation Safety Board (NTSB) is investigating the accident to determine what went wrong.

An initial Cause Map, a visual root cause analysis, can be built to analyze and document what is known about this train-car collision.  A Cause Map visually lays out the cause-and-effect relationships that contributed to an issue and focuses on understanding all the causes, not THE root cause.  Generally, identifying more causes results in a greater number of potential solutions being considered.

So why did the train hit a vehicle?  Eyewitnesses have stated that the SUV was hit by a crossing gate as it descended.    It is not clear why the SUV didn’t stop prior to entering the railroad crossing area. The driver pulled the SUV forward onto the tracks rather than backing up and the train struck the vehicle shortly after.  Investigators don’t know why the driver stopped on the tracks, but initial reports are that all safety features, such as the crossing gate, signs and train horn, were functioning properly at the time of the accident.

Unfortunately, it’s not unusual for passengers in a vehicle struck by a train to be injured or killed, but it is less common for fatalities among the train passengers.  Investigators are working to determine what made this accident particularly dangerous for train passengers.  The NTSB plans to use information about the passengers’ injuries and a diagram of where people were sitting on the train to try to understand what happened during the collision.  Post-accident photos of the train show that significant fire damage occurred, likely fueled by the gas in the SUV.

One of the open questions is whether the electrified third rail contributed to the accident and subsequent injuries. Metro-North uses an unusual “under-running” third rail design where power is taken from the bottom of the rail.  During the collision, 400 feet of the third rail broke apart and 12 pieces pierced both the SUV and the train. This rail design uses a metal shoe that slips underneath the third rail and some think that the force of the collision may have essentially pried up the rail and threw it into the train and vehicle.

Open questions can be documented on the initial Cause Map with a question mark.  As more information becomes available, the Cause Map can quickly be updated.  Typically, Cause Maps are built in Excel and different versions can be saved as different sheets to document the investigation process.

Click on “Download PDF” above to view an initial Cause Map of this accident, built from the information in the media articles on the accident.

Root Cause Analysis - Incident Investigation

Prison Bus Collides With Freight Train

By Kim Smiley

On the morning of January 14, 2015, a prison bus went off an overpass and collided with a moving freight train.  Ten were killed and five more injured.  Investigators believe the accident was weather-related.

This tragic accident can be analyzed by building a Cause Map, a visual root cause analysis.  A Cause Map visually lays out the cause-and-effect relationships to show all the causes (not just a single root cause) that contributed to an accident.  The first step in the Cause Mapping method is to determine how the incident impacted the overall organizational goals.  Typically, more than one goal needs to be considered.  Clearly the safety goal was impacted because of the deaths and injuries.  The property goal is impacted because of the damage to both the bus and train (two train cars carrying UPS packages were damaged).  The schedule goal is impacted because of the delays in the train schedule and the impact on vehicle traffic.

The Cause Map itself is built by starting at one of the impacted goals and asking “why” questions. So why were there fatalities and injuries?  This occurred because there were 15 people on a bus and the bus collided with a train.  The bus was traveling between two prison facilities and drove over an overpass.  While on the overpass, the bus hit a patch of ice and slid off the road, falling onto a moving freight train that was passing under the roadway.  No one onboard the train was injured and the train did not derail, but it was significantly damaged.  The bus was severely damaged.

The prisoners onboard the bus were not wearing seat belts, as is typical on many buses.  They were also handcuffed together, although it’s difficult to say how much this contributed to the injuries and fatalities.

Useful solutions to prevent these types of accidents can be tricky.  The prison system may want to review how they evaluate road conditions prior to transporting prisoners.  This accident occurred early in the morning and waiting until later in the day when temperatures had increased may have reduced the risk of a bus accident.  Transportation officials may also want to look at how roads, especially overpasses, are treated in freezing weather to see if additional efforts are warranted.

To view a high level Cause Map of this accident, click on “Download PDF” above.

You can also read our previous blogs to learn more about other train collisions:

Freight Trains Collide Head-on in Arkansas

Freight Train Carrying Crude Oil Explodes After Colliding with Another

“Ghost Train” Causes Head-on Collision in Chicago

Deadly Train Collision in Poland

Root Cause Analysis - Incident Investigation

Safety Concerns Raised by 5 Railroad Accidents in 11 Months

By ThinkReliability Staff

The National Transportation Safety Board investigates major railroad accidents in the United States. It was not only the severity (6 deaths and 126 injuries) but the frequency (5 accidents over 11 months) of recent accidents on a railroad that led to an “in-depth special investigation“. Part of the purpose of the special investigation was to “examine the common elements that were found in each”.

When an organization sees a recurring issue – in this case, multiple accidents requiring investigation from the same railroad, there may be value in not only investigating the incidents separately but also in a common analysis. A root cause analysis that addresses more than one incident is known as a Cumulative Cause Map, and it captures visually much of the same information in a Failure Modes and Effects Analysis, or FMEA.

The information from the individual investigations of each of these accidents can be combined into one analysis, including an outline addressing the problems and impacts to the goals from the incidents as a whole. In this case, the problems addressed include issues on the Metro-North railroad in New York and Connecticut from May 2013 to March 2014. The five incidents during that time period resulted in 4 customer deaths and 126 injuries, 2 employee deaths, and over $23.8 million in property damage.

The analysis of the individual accidents can be combined in a Cumulative Cause Map to intuitively show the cause-and-effect relationships. The customer deaths and injuries, and the property damage, resulted from train derailments and a collision. The train collision resulted from a derailment. In two of the cases, the derailment was due to track damage that had either been missed on inspection or had maintenance deferred. In the third derailment (discussed in a previous blog), the train took a curve at an excessive rate of speed due to fatigue of the engineer. Inadequate track inspections and maintenance, and deferred maintenance were highlighted as recurring safety issues to the railroad.

Both of the employee fatalities resulted from workers being struck by a train while performing track maintenance. In one case, the worker was outside the designated protected area due to an inadequate job safety briefing. In the other, a student removed the block while working unsupervised, allowing a train to travel into the protected area. The NTSB also identified inadequate safety oversight and roadway worker protection procedures as areas needing improvement. While the NTSB already released recommendations with each of the individual investigations, it plans to issue more based on the cumulative investigation addressing all five incidents. View an overview of all 5 incidents by clicking “Download PDF” above.

Root Cause Analysis - Incident Investigation

Chicago O’Hare Commuter Train Derailment Injures 33

By Sarah Wrenn

At 2:49 AM on March 24, 2014, a Blue Line Commuter train entered the Chicago-O’Hare International Airport Station, collided with the track bumper post, and proceeded to derail landing on an escalator and stairway.  Thirty-two passengers and the train operator were injured and transported to nearby hospitals.  Images showing the lead rail car perched on the escalator look like the train was involved in filming an action movie.

So what caused a Chicago Transit Authority (CTA) train, part of the nation’s second largest public transportation system, to derail?  We can use the Cause Mapping process to analyze this specific incident with the following three steps: 1) Define the problem, 2) Conduct the analysis and 3) Identify the best solutions.

We start by defining the problem.  In the problem outline, you’ll notice we’ve asked four questions: What is the problem? When did it happen? Where did it happen? And how did it impact the goals?

Next we’ll analyze the incident.  We start with the impacted goals and begin asking “why” questions while documenting the answers to visually lay out all the causes that contributed to the incident.  The cause and effect relationships lay out from left to right.  As can be seen in the problem outline, this incident resulted in multiple goals being impacted.

In this incident, 33 people were injured when the train they were riding derailed in the O’Hare station thereby affecting our safety goal of zero injuries.  The injuries were caused by the train derailing, so let’s dig in to why the train derailed.  Let’s first ask why the train operator was unable to stop the train.  Operator statements are crucial to understanding exactly what happened.  Here, it is important to avoid blame by asking questions about the process followed by the operator.  Interestingly, 45 seconds before the crash, the operator manually reduced the train speed.  However, at some point, the train operator dozed off.  The train operator’s schedule (working nearly 60 hours the previous week), length of shift, and time off are all possible causes of the lack of rest.  Evidence that the operator was coming off of an 18 hour break allows us to eliminate insufficient time off between shifts as a cause.  In addition, the train operator was relatively new (qualified train operator in January 2014), but also she was an “extra-board” employee meaning she substituted for other train operators who were out sick or on vacation.

Next, let’s ask why the train was unable to stop.  An automatic breaking system is installed at this station and the system activated when the train crossed the fixed trip stop.  The train was unable to stop, because there was an insufficient stopping distance for the train’s speed.  At the location of the trip stop, the train speed limit was 25 mph and the train was traveling 26 mph.  While the emergency braking system functioned correctly, the limited distance and the speed of the train did not allow the train to stop.

The train derailing impacted multiple organizational goals, but also the personal goal of the train operator who was fired.  During the investigation, we learn that the train operator failed to appear at a disciplinary hearing and had a previous safety violation in which she dozed off and overshot a station.  These details reveal themselves on the cause map by asking why questions.

The final step of the investigation is to use the cause map to identify and select the best solutions that will reduce the risk of the incident recurring.  On April 4, 2014, the CTA announced proposed changes to the train operator scheduling policy.  In addition, the CTA changed the speed limit when entering a station and moved the trip stops to increase the stopping distance.   Each of these identified solutions reduce the risk of a future incident by addressing many of the causes identified during the investigation.