Posted on 02/17/2023 9:44:54 AM PST by conservative98
Harder?
Even when each rail car has it's OWN brakes?
I can understand a braking difference for an unloaded vs loaded semi truck.
He is NOT gonna like that!
I see what you did here!!
On a related note, from an Upstate NY enemedia outlet, get a load of this headline...
“”Longer, heavier trains make it harder to brake in an emergency
When a train using conventional air brakes tries to stop, the air pressure signal is sent sequentially at a speed slightly slower than sound from railcar to railcar, generating increasing amounts of “in-train forces” because of individual cars pushing and pulling against one another, as cars at the front of a train begin to reduce speed before cars at the back.
The longer the train, the more difficult it is to skillfully stop, and the more likely it is an emergency braking scenario goes awry.””
Here is my explanation -
Each individual train car has its own air brake system. This train was 1.9 miles long with over 150 cars. The system is not “computerized” so you would need the same exact braking coefficient and activation on each car to optimize the stopping ability in a smooth fashion, but that does not happen because you have 151+ systems in play along a track.
There are newer brakes and older brakes, more weight or less in each car, different coefficients for each piece of track and wheel, and and there is the time delay of the subsonic signal from the engineer to each individual car so at speed you have a lot of forces pushing and pulling.
The braking systems obviously work in most applications but there is also tension created up and down the length of the train due to all of these differences. The bigger the train is the longer it takes to stop (momentum) and the more likely it is to have something go wrong.
This is how/why you sometimes see train cars shudder or vibrate violently even at low speeds because there are so many dynamic forces generated within the train itself. The more cars and mass the more these oppositional forces are generated impacting “braking” AND making a catastrophic failure more likely.
Trains are getting longer and the railroad companies will tell you that this makes for more efficiency and lower carbon emissions. It also makes more money for them and I am okay with that generally. However, the longer the trains are the more likely it is that something can go wrong and “derailments” have increased.
There needs to be a balance when they are transporting hazardous materials. If it were 150 cars of minimal hazards it is not a big deal, but when you are transporting a devils brew of ethyl-methyl death to include chemicals that can combine into something even worse (like this recent one) it would be better to have a smaller train to reduce overall risks. It also might be reasonable to separate cars with certain chemicals that might combine into something far worse in the event of a catastrophic derailment (not always the fault of the railroad).
Just my .02
Norfolk Southern rolled the dice (like all of them) and they made more money, but this incident is going to bite them in the butt and IF the contaminants begin to show up in waters downstream or in well water it might be catastrophically expensive.
Boeing did the same thing with the 737 and that did not work out too well. Profit ahead of “safety” usually catches up to you at some point.
If you are interested there is a clip within this awful podcast (I apologize in advance for the language - never watched it and have no earthly idea why so many “podcasters” think gratuitous cursing is a good thing) but here is an engineer (allegedly) talking about what happened and he makes some very valid points that are in line with my reasoning -
The comments by the engineer start around 3:20 and its very short (couple of minutes) but it details why these longer trains are harder to manage. Keep in mind that the railroad is currently trying to get rid of the second employee on the trains to save money so the union opposes this and that is mostly what the “strike” was/is about.
thanks for the information!
very interesting to more fully understand the situtation.
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