AnthonyVIf the g-forces experienced by a railroad car are so high, how does any of the lading ever survive a trip?
Much of what railroads carry is not too sensitive to such forces. If the cargo is sensitive, the car will usually be noted "do not hump."
It should be noted, too, that a given lading may not be subject to many such moves, but the car itself will be subject to such movements somewhat frequently.
And damage to lading does occur.
As I recall, coupling speed is generally supposed to be under something like 4 mph. That's still a pretty good knock.
Larry Resident Microferroequinologist (at least at my house) Everyone goes home; Safety begins with you My Opinion. Standard Disclaimers Apply. No Expiration Date Come ride the rails with me! There's one thing about humility - the moment you think you've got it, you've lost it...
Overmod Semper Vaporo The company I worked for got into the business of electronics to be put on individual RR cars. In order to understand the "G"-forces the equipment would be subjected to, they sent some of the members of the Metrology department to a RR to put their instruments on the cars to measure what happens in normal use. These are guys and the equipment that did the testing of the electronics we built for Space Shuttle to prove it could take the stress of "blast-off" and "re-entry". The instruments registered forces that were OFF THE SCALE! They had to come back and get equipment that would measure higher "G"-forces! While we're at it, and to put this in some (still-astounding-to-me) context, Amtrak did some accelerometer testing of VERTICAL shock forces for an Acela running between Boston and New York. What was the peak reading determined during this test? (special recognition to the first one who knows it) Out of curiosity: what WAS the magnitude of the actual force measured by your metrology people?
Semper Vaporo The company I worked for got into the business of electronics to be put on individual RR cars. In order to understand the "G"-forces the equipment would be subjected to, they sent some of the members of the Metrology department to a RR to put their instruments on the cars to measure what happens in normal use. These are guys and the equipment that did the testing of the electronics we built for Space Shuttle to prove it could take the stress of "blast-off" and "re-entry". The instruments registered forces that were OFF THE SCALE! They had to come back and get equipment that would measure higher "G"-forces!
The company I worked for got into the business of electronics to be put on individual RR cars. In order to understand the "G"-forces the equipment would be subjected to, they sent some of the members of the Metrology department to a RR to put their instruments on the cars to measure what happens in normal use.
These are guys and the equipment that did the testing of the electronics we built for Space Shuttle to prove it could take the stress of "blast-off" and "re-entry".
The instruments registered forces that were OFF THE SCALE! They had to come back and get equipment that would measure higher "G"-forces!
While we're at it, and to put this in some (still-astounding-to-me) context, Amtrak did some accelerometer testing of VERTICAL shock forces for an Acela running between Boston and New York. What was the peak reading determined during this test? (special recognition to the first one who knows it)
Out of curiosity: what WAS the magnitude of the actual force measured by your metrology people?
If the g-forces experienced by a railroad car are so high, how does any of the lading ever survive a trip?
Anthony V.
What I was talking about is a locking dog that would act like a deadbolt to lock the air brake in the applied position. The locking dog would be held in release by air, and moved to lock position by spring when the air is removed.
For switching where a cut is broken up, the air in the cars would be bled so the brake pistons retract and release. Then when you let the air out of the locking dogs, they cannot lock the brakes when the brakes are in the released position.
If anything, I can see greater use of ECP brakes (already existing technology), with electric handbrakes tied into the system. Press a button, and KA-CHUNK, 100% handbrake application.
It's been fun. But it isn't much fun anymore. Signing off for now.
The opinions expressed here represent my own and not those of my employer, any other railroad, company, or person.t fun any
UPrailfan When that air is gone the Parking brakes are ON and then you have to recharge them to move them
When that air is gone the Parking brakes are ON and then you have to recharge them to move them
That'd be neat on a hump. Or when the brake system breaks at a neat spot on the mainline. I guess you'd have to cage the brakes or something. Sounds like a nightmare.
And when that air bleeds out?
KISS principle.
With OTR trailers if there is any way of Bottling the air in the system they will roll Freely. You only need the service line to apply the brakes. A simple Valve where they can save the air when the brakes are released is enough.
Sorry called lost my old Job and for employment I just enrolled in OTR Training and am amazed the RR's are not using this system
Don't Roadrailers have spring-loaded brakes on the bogies?
But the question is: how can you hump cars with spring loaded brakes?
petitnj 5. Why wasn't there a derail on the downhill side of the parked train? That is common practice on most sidings and yards.
5. Why wasn't there a derail on the downhill side of the parked train? That is common practice on most sidings and yards.
Derails protect Main Tracks from unwanted movements on sidings and spurs - my understanding is that the train was tied down on the Main Track.
Never too old to have a happy childhood!
1. Compasses don't measure true north. (Can Dead Men Vote Twice? Compass Deviation Magnetic Variance True)
2. As stated above the brutal environment of railroading lead to very simple and effective control systems.
3. Even the simple Westinghouse Air Brake needs special attention and will fail for a number of reasons.
4. The thousands of trains that are successfully tied down each day is testimony to the effective system and rules in place.
Every Class 1, 2 and 3 railroad will have the same phrase in their rule book about securing cars.
The crew is to apply sufficient hand brakes, (no mention of air brakes) to prevent movement.
The crew is not to take into consideration the application of the air brake, nor are they allowed to assume the air brakes are sufficient to hold the cars or train.
We apply the air as an additional safety measure, but the train must be secured with a sufficient number of manually applied hand brakes on the cars, (not including the engines) to prevent movement.
The carriers want the crews down there doing this by hand simply because this relies on the crew, not the technology to secure the train.
None of the carriers rules books I have ever seen give a specific number of brakes beyond a required minimum…on my railroad, outside of yards, any train must be secured with at least 2 working hand brakes, the brakes must be tested before the locomotives are cut away, and the crew is required to observe the standing cut to insure the cars remain in place.
If a locomotive(s) is to be left attached to the train, there must be sufficient hand brakes applied to the cars to prevent movement of the entire train, locomotives included, once that is determined and tested, the engineer must make a minimum 20lb brake pipe reduction, and apply the independent, waiting until the locomotive brakes are fully exhausted, then apply a hand brake to each locomotive, and isolate each locomotive.
All of these steps are backups to the step just taken.
I grasp the “flip the switch” concept, but in essence, once we make sure the train is secure, we do, in a manner of speaking, flip a switch, we exhaust all the air out of the brake pipe, setting all the air brakes on the cars, as a backup to the hand brakes original test.
Done properly, no train should ever roll away on its own.
Think about how many trains get parked every day with none rolling away….this is one instance out of how many thousands of tie downs every day, and no one has yet to offer any proof that this train was not tied down properly, so the only alternative is some outside force altered the situation.
What that force may have been is the real question…like I mentioned in another thread, I doubt the engineer would have walked away from his train, knowingly leaving it un-secured, and pointing directly at the place he was planning on sleeping in.
Could this have been caused by a mechanical defect?
Maybe, but every freight train gets a serious inspection before it ever leaves a yard or industry, and an initial terminal brake test, required every thousand miles after the
Could this be an operational defect?
Again, maybe, parking a crude oil train on a down grade pointed towards an inhabited area might be taking an un-necessary risk, although the siding used has been used to park trains for years and years with none running away.
Could someone later have accidentally done something to cause the runaway?
Yes.
Could this have been done on purpose?
Yes, there is a possibility someone was that stupid, misguided or evil.
And by the way, my father was a quartermaster in the US Navy, responsible for the navigation equipment on his ship, and the training of navigators, and I still have two of his sextants.
With that one tool, a good accurate watch, a "true" compass and an accurate set of charts, he taught me enough that I can get you into any port in the world, and I bet most of the Marines here who served before the advent of GPS can get you within a hundred yards of a land based target with a wristwatch, a compass and a good map.
They still teach navigation at the Academy for a good reason.
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edblysard {SNIP} The electronics wouldn’t survive flat switching, you really have to be standing right there to understand the forces applied to a coupler, so the automatic air and brake and un- coupler idea, while suitable for light mass transit, wouldn’t live on a freight train, and with each new doodad, the cost of maintaining the cars goes up, as does the odds of something breaking and needing repair. {SNIP}
{SNIP}
The electronics wouldn’t survive flat switching, you really have to be standing right there to understand the forces applied to a coupler, so the automatic air and brake and un- coupler idea, while suitable for light mass transit, wouldn’t live on a freight train, and with each new doodad, the cost of maintaining the cars goes up, as does the odds of something breaking and needing repair.
You guys play rough with your toys! (And for the most part, your toys take it in stride!)
Semper Vaporo
Pkgs.
Ulrich The other thing I don't understand is how a massive train can get away without any bells and whistles going off all over the place, in dispatch and at headquarters, and why brakes could not be applied from a remote location . One has to wonder if badly outdated technology had a part to play in the Lac Megantic accident.
The other thing I don't understand is how a massive train can get away without any bells and whistles going off all over the place, in dispatch and at headquarters, and why brakes could not be applied from a remote location . One has to wonder if badly outdated technology had a part to play in the Lac Megantic accident.
If you have a system such as CTC, A movement past a signal would be seen on the dispatcher's board. However, the MM&A is all dark territory, under Occupancy Control System, which requires direct communication, by radio usually, between the dispatcher and the crew of the engine/train. So, if there is no one with the engine or train, the dispatcher has no immediate way to know of any movement.
Johnny
I agree that everything should be as simple as possible. But that does not rule out some incredibly complex systems to get the job done if that is what is needed. I am not suggesting powered, simultaneous parking brakes for universal application to all freight cars. I see it as an exclusive feature for oil unit trains.
I only think it might come to past because oil trains will come under intense scrutiny in the wake of this Lac-Megantic crash and the backdrop of activism fighting to end shipping oil by rail by piling on new safety regulations.
For the industry, it will be either sink or swim. And if they manage to swim, we will be looking at a whole new breed of crude oil train. Powered, simultaneous parking brakes will be just one of many new and innovative features. I don’t see these brakes as being delicate or electronic. They could be pneumatic powered, and robust enough to stand up in service. They don’t have to be something that is presently used in transit systems.
These new trains would likely be made up of semi-permanently coupled cars that are not interchanged. Being in such captive service, they would be ideal candidates for ECP brakes, and all the operation monitoring that that system enables.
The cars themselves will probably be much different than today’s sinister looking straight black cylinders sitting completely atop the truck bolsters.
There's much to be said for keeping things simple and primitive, I agree, but at some point simple and primitive no longer becomes better and faster. How long does it take a conductor or engineer to properly tie down a train? I really don't know. But if he/she has to walk back to each locomotive and car I would guess its a significant amount of time. What if the law states a minimum of 11 handbrakes need to be set and the train starts to roll after the seventh one was set... the conductor hasn't had the time to set the minimum number and he/she is ultimately blamed for not securing the train properly. An admittedly more complex system that would set all hand brakes instantaneously with a flip of the switch would eliminate that scenario and would be preferable and perhaps more efficient as no time would be lost in having people doing this cumbersome and sometimes dangerous task.
But your point is well taken. Perhaps its more a question of employing technology intelligently verses keeping things as simple as possible or using technology just because its available. At some airports now they have laser activated paper dispensers in their washrooms. That's a good example of needless technology overkill, in my opinion. On the other hand simple star charts served mariners well for centuries yet are no longer relied upon to navigate super tankers. It comes down to applying the latest technology intelligently.
The fact is, because it is so simple and “primitive” it works better and faster…imagine every time you wanted to start your car, you had to call someone to flip a switch.
Having a manual hand brake allow us to place cars where we want this when we want them, and then move them quickly to another location.
As it stands, I can change a coupler knuckle with nothing more than a pair of pliers, if that, and the same for a cut lever.
While most of the newer locomotives do have electric hand brakes, the mechanics of adding that to a freight car gets expensive…you need a power supply to begin with, then a way to activate it, then a way to protect it from the elements, and place it in a manner that makes it serviceable….and each car would have to have some form of radio or Wi-Fi identification, a receiver, and a transmitter to tell you the brakes applied.
As odd as it sounds, we are more efficient with the manual devices than with all the gadgets.
I can set a hand brake in the yard to act as a bumper, a car we can kick against, and I can tell how tight I need it by the way it feels, I want it to be tight enough to retard the motion or absorb the impact of the cars I kick, but not so tight as to slide the wheels.
I doubt you could invent a self-winder that could “feel” the brake setting as well as I can.
The whole idea is the less “parts” or stuff you have to use, the faster and easier it is.
Just like in the hardware/hand tool industry, someone is always trying to reinvent the hammer, but the truth is, nothing works better for pounding a nail into a board but a good old 16oz Stanley hand hammer.
UlrichTying down a train by having someone climb aboard each locomotive and car to turn a hand brake sounds like something out of the dark ages. In this day and age can't that somehow be done by flipping a switch in the locomotive?
All that is needed is a way to guarantee that air brake leak-down cannot release the brakes. I would accomplish that by adding a form of deadbolt or cam action to the linkage system coming out of the air brake cylinder.
To set the parking brake, you set the air, and then set a mechanical lock to hold the linkage in the set position. This mechanical lock could be held in release by the air, and set by spring force.
That way if you are running the train, and the brake lock release air fails, and the spring tries to set the lock, it can only insert the lock when the air brakes are fully set. It cannot insert the lock when the air brakes are released and the train is underway.
So there is no way that an inadvertent setting of the brake lock can cause a derailment by locking the brakes when they are released.
So this would be a spring activated locking mechanaism that would hold the air brake cylinder when fully applied, and keep it applied even if the air pressure in the cylinder leaked off. This locking device would be pneumatically powered. It would have to be explored further to see if it could be powered off of the train line as a normal part of the brake function. I am thinking that it would need a separate train line.
Tying down a train by having someone climb aboard each locomotive and car to turn a hand brake sounds like something out of the dark ages. In this day and age can't that somehow be done by flipping a switch in the locomotive? I can understand why a tired engineer or conductor might tie down only a few cars and call it good enough.
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