Ep 54 Big Bayou Canot Rail Accident
Engineering News – Safer Helmets (1:50)
This week's engineering failure is the Big Bayou Canot Rail Accident (4:35). Big Bayou Canot became the second worst US rail disaster (9:50) after a towboat hit a bridge resulting in extensive damage (22:55). The ensuing investigation offered a number of important lessons learned (26:35) and recommendations.
Big Bayou Canot Rail Accident
Big Bayou Canot Rail Accident
Hi and welcome to Failurology; a podcast about engineering failures. I’m your host, Nicole
And I’m Brian. And we’re both from Calgary, AB.
Thank you again to our Patreon subscribers! For less than the cost of a functional hammer, you can hear us talk about more interesting engineering failures!
This week in engineering news, safer helmets
Researchers at Johns Hopkins University (yes John is plural), specifically the Hopkins Extreme Materials Institute
Shock absorbing material protects like metal, but is lighter, stronger and reusable with “extreme energy absorption capability”
They added strength with high energy absorbing liquid elastomers (LECs) which are common in actuators and robotics
The test included strikes from objects weighing 2-7kg and speeds up to 35 kph. And they are confident that the material can withstand greater impacts
The team is collaborating with industry to design helmets for athletes and the military
In addition to helmets, some ideal applications are body armour, as well as car and aerospace parts
If you want to read more on the study, check out the link the webpage for this episode at failurology.ca
Now on to this week’s engineering failure; the Big Bayou Canot rail accident.
Sept 22, 1993
Derailing an Amtrak train on the Big Bayou Canot Bridge near Mobile Alabama
A barge being pushed by the towboat Mauvilla made a wrong turn on the Mobile River and ended up on the Big Bayou Canot which is an unnavigable channel.
The towboat crew included a captain, pilot and two deckhands. The pilot took over control of the boat from the captain around 1130pm.
There was heavy fog and the towboat pilot was not properly trained on how to read radar. The boat also didn’t have a compass or a chart of the waters - because of all of these things, they weren’t even aware they were off track
The fog was so dense that the pilot couldn’t see the front of the barge he was pushing. And he was trying to find a place to tie to the bank of the river until the fog passed.
Looking at the bridge and waterway locations on a map, the mobile river and big bayou canot (which looks like a small river) kind of run in parallel for a bit, but they both meander. From what i can tell, he went left at a wye insead of right and the train bridge was maybe 500-1000m after that wye.
Another factor - they had allowed a faster towboat to pass them about 30 minutes before they hit the bridge, so when the pilot saw the bridge on the radar, he thought it was the other boat.
At 2:45am the towboat hit the bridge, which had a span that COULD be converted into a swing bridge, even though no such conversion was made. When the boat hit the bridge, it knocked this span about 1m out of alignment and put a severe kink in the track
The pilot saw the bridge on his radar, but thought it was another tug boat - still doesn’t quite explain why he ran into it, but either way he was found not to be criminally liable.
8 minutes later at 2:53am the Sunset Limited train travelling from LA to Miami reached the bridge.
Traveling by train from Los Angeles to Miami usually takes around 102 hours and 14 minutes, but the fastest Amtrak train can make the trip in 93 hours and 40 minutes.
The Sunset Limited is an Amtrak passenger train that for most of its history has run between New Orleans and Los Angeles, over the nation's second transcontinental route. However, up until Hurricane Katrina in 2005, it ran between Orlando and Los Angeles, and from 1993 to 1996, continued on to Miami (via the Silver Meteor's route). It is the oldest continuously operating named train in the United States, introduced in 1894 by the Southern Pacific Railroad, and acquired by Amtrak upon its formation in 1971.
The train was powered by three locomotives or engine cars, had 8 passenger cars and was carrying 220 passengers and crew. The train was travelling at 113kph because the conductor had no idea there was an issue with the bridge.
The three locomotives hit the displaced span first and that part of the bridge collapsed into the water below. The lead locomotive, which had only been in service with Amtrak for 20 days, embedded itself into the canal bank on the other side of the river in about 14m of mud. And the three locomotives, baggage car, sleeping car and two of the six passenger cars fell into the water. The passenger cars were double decker cars. (tell the double decker bus story about sitting in the front but driving on the wrong side of the road)
The fuel tanks on the locomotives, which each held tens of thousands of liters, ruptured with the collision and leaked into the river and caught on fire.
The conductor and assistant conductor were in the second last car at the time of accident and stated that there was no warning - no horn blast, no brakes, no communication from the crew
It's important to note that this is the middle of the night and its foggy. And there are no lights. So the towboat felt a “bump” and then saw flames 5-10 minutes later, but had really no idea what was going on at first. The pilot ended up saving 17 people after the crash.
Despite substantial displacement of the bridge, the continuously welded rails didn’t break. Which meant that the track circuit controlling the approach signals remained intact. The signal before the bridge displayed green, which meant all clear. Had it displayed red (stop) or amber (caution) the conductor would have had enough time to stop the train or at least reduce its speed.
The signal operator was in Jacksonville Florida, but again, they had no idea there was an issue with the track because the contact signal did not break.
47 deaths, mostly from drowning as well as fire and smoke inhalation, 103 injuries
Deadliest train accident in Amtrak’s history
Worst rail disaster in US after the 1958 Newark Bay rail accident which killed 48 people
Fun fact - the train was 30 minutes behind schedule due to air conditioning and toilet repairs in New Orleans. Had it been on schedule, this wouldn't have happened.
The girder section was destroyed, which is the part that COULD be swung out. This is also what we will call the middle section.
The truss section, the segment that the train passed over first, sustained extensive damage.
And the third section was destroyed during the derailment, mostly because the train drove right into it.
The nose of the south pier had some concrete chipping from where the barge hit it
Some portions of the bridge were found 15m north of their original location
Costs - in 2022 dollars are in () and are roughly double 1993 dollars
Rail equipment - $16 million ($31 million)
Track and bridge - $2 million ($3.9 million)
Rerouting - $1.7 million ($3.3 million)
Marine Equipment - $1,250 ($2,400)
Pollution cleanup - $117,000 ($228,000)
Total - $19,818,250 ($38,559,594)
Lessons learned / Conclusions
There was a lack of a national risk assessment program to determine bridge vulnerability to marine vessel collision. This prevented the railroad industry from taking action to increase protection. (we know how America feels about their bridges)
The train crew’s qualifications and the condition of the track, signals or train equipment didn’t contribute to the accident
Had the towboat pilot known how to read the radar properly, he wouldn't have made a wrong turn. Which his company should have made sure he was adequately trained to do. The Coast Guard also didn’t require that he be trained in radar navigation. The pilot also used poor judgment by continuing to navigate when he couldn’t find a spot to stop, by continuing to approach an unidentified object on the radar and by not getting help from the crew.
The boat crew were tested for drugs and alcohol, but this occurred 10 hours after the accident and are not conclusive either way. This is not to say that they were under the influence of drugs or alcohol, but that the delay in testing is an procedural issue that should be corrected. In fact, the regulations for post accident testing did not specify a time limit to conduct testing.
Because passengers can purchase tickets on the train and board and leave the train at their leisure, Amtrak was unaware exactly how many passengers there were. And the list they did have took until the next day to get to the emergency responders. Which was a disadvantage to the rescue.
Despite the remoteness of the accident site, weather conditions, and limited modes of transportation to get to the accident (which was pretty much boat only) the emergency response was found to be well coordinated and effective.
So there you have it, the Big Bayou Canot Rail Accident. A barge hit a bridge and knocked the rails off track, causing a train to derail in the middle of the night. Better bridge risk assessment programs, a qualified towboat pilot or even better rail sensor equipment could have prevented this derailment.
For photos, sources and an episode summary from this week’s episode head to Failurology.ca. If you’re enjoying what you’re hearing, please rate, review and subscribe to Failurology, so more people can find us. If you want to chat with us, our Twitter handle is @failurology, you can email us firstname.lastname@example.org, you can connect with us on Linked In or you can message us on our Patreon page. Check out the show notes for links to all of these. Thanks, everyone for listening. And tune in to the next episode where we will talk about the PIP breast implant recalls. This will be our first medical related engineering failure. I've wanted to do one since we started the show, so we are pretty excited about it.
Bye everyone, talk soon!