dehusman If the engines die, there is no source of air. Its bottled. Depending on the integrity of the train line, the air will bleed off the train depending on the quality of the gaskets in the air hoses, the quality of the joints in the train line, the quality of the seals in the brake valves and cylinders. One method of testing air brakes is the air flow method. If a train line has an air flow of less than 60 cfm of air flow in it, its considered "good". That means that a "good" train line can have leaks in it that bleed off up to 59 cfm of air. Sooner or later, with no air source, the air brakes are going to bleed off. The more difficult option requires an understanding that air is a fluid., a compressable fluid. It is against the rules to "bottle" the air on a cut that is to set the brakes and close the angle cocks on both ends of the cut. Once the engines died the train was essentially a cut with the air bottled. Since air is a fluid its possible to get waves in it. At the wave the pressure is higher than on either side of the wave. If the engine or air compressor failed suddenly its possible that the sudden stop set up a wave going down the train line (think water hammer in water line when you shut off a faucet). If the pressure in the wave was high enough, the brake cylinder would interpret the increase in pressure as the brakes being release. Seeing the brakes being released the brake valve would dump air from the reservoir and the emergency reservoir into the train line to speed the release, that in turn would cause the next car to see a bigger increase in pressure and cause that car to release, etc. Within a few minutes most or all the cars have their brakes released.
If the engines die, there is no source of air. Its bottled. Depending on the integrity of the train line, the air will bleed off the train depending on the quality of the gaskets in the air hoses, the quality of the joints in the train line, the quality of the seals in the brake valves and cylinders. One method of testing air brakes is the air flow method. If a train line has an air flow of less than 60 cfm of air flow in it, its considered "good". That means that a "good" train line can have leaks in it that bleed off up to 59 cfm of air. Sooner or later, with no air source, the air brakes are going to bleed off.
The more difficult option requires an understanding that air is a fluid., a compressable fluid. It is against the rules to "bottle" the air on a cut that is to set the brakes and close the angle cocks on both ends of the cut. Once the engines died the train was essentially a cut with the air bottled. Since air is a fluid its possible to get waves in it. At the wave the pressure is higher than on either side of the wave. If the engine or air compressor failed suddenly its possible that the sudden stop set up a wave going down the train line (think water hammer in water line when you shut off a faucet). If the pressure in the wave was high enough, the brake cylinder would interpret the increase in pressure as the brakes being release. Seeing the brakes being released the brake valve would dump air from the reservoir and the emergency reservoir into the train line to speed the release, that in turn would cause the next car to see a bigger increase in pressure and cause that car to release, etc. Within a few minutes most or all the cars have their brakes released.
Boy, you really don't have clue do you? I'm not sure all the King's horses and all the King's men can straighten that bunch of poppycock out!
.
Euclid You mention a case where brakes in emergency bled off in less than one minute. First, I am greatly surprised that it could leak off that fast.
You mention a case where brakes in emergency bled off in less than one minute. First, I am greatly surprised that it could leak off that fast.
So were we.
You must have heard compressed air leaking loudly in a major flow of leakage in order for the cylinders and reservoir to lose their pressure in one minute.
Not really if it was from multiple points and there really wasn't a huge volume of compressed air.
The point of that example was not to suggest that all cars bleed off in one minute it was that all cars leak are and eventually all will go to zero air pressure and zero braking. Some faster than others. Some have suggested an emergency application should last for weeks, the point of the story is that while there might be some cars that last for week, there are also cars that bleed off in minutes, so a person can't count on the air brake system disconnected from an air source to be a long term hold. Sooner or later the air will leak off.
I also do not understand why you are making a point about an emergency application leaking off, together with a point about the trainline leaking off. With brakes left in emergency, the trainline is 100% exhausted, so there is nothing to leak off.
Sure there is. Go read how air brakes work. When the brakes are applied (regardless of the type of application) air is vented into the cylinders, pressurizing them and pushing the piston out, which causes the brake shoes to be pushed against the wheels through a mechanical linkage. Did you catch where the air pressure is? Its in the cylinders. If there is no pressure in the reservoirs because it was vented into the cylinders and there is no pressure in the train line because the emergency application vents to atmosphere, the only place there is pressure is in the cylinders, the things keeping the brakes against the wheels. When the air leaks out of the cylinders (either back through the brake valve, through the seals on the brake rod or the brake piston), the cylinder loses pressure and brakes release.
The assumption is that the shutdown of the engine and loss of air pumping caused the brakes to release from the service application.
I know trainlines always have leakage, but would a leak down of the trainline with brakes in service application cause the brakes to release? I would like a simple answer to that question.
You are asking the wrong question, its not a matter of a leak in the train line causing a release in the brakes, its can a train line NOT CONNECTED TO AN AIR SUPPLY bleed off and release. If there is no air supply at some point in time the entire brake system will leak off. The question is how long and there is no set answer for that. Could be minutes, could be a week.
However, in the very largest perspective: I am not even suggesting that ECP brakes would aid in securing a train because the rules would not allow it in the first place. Basically, overall, my response is to your point that braking improvements are worthless because you can cite a couple wrecks where braking would not have helped, despite the fact that it would help in many types of derailments.
I never said they were worthless, its just that you keep bringing them up as a solution to the CBR derailment problem. Its not that I can cite a couple wrecks where ECP braking would not have helped, its that I can't find one where it would have helped. Spending billions of dollars on a solution that doesn't solve the problem isn't a solution. If the problem is how do you keep another oil train wreck from becoming a "towering inferno", the answer is in bringing the flammable liquid cars closer to the specs of the flammable gas cars. That solution has a history and track record that is successful. It is a proven solution, its just not sexy.
Dave H. Painted side goes up. My website : wnbranch.com
dehusmanIf the engines were shut down and the train line bled off then there was no air pressure in the system to apply the brakes.
RIDEWITHMEHENRY is the name for our almost monthly day of riding trains and transit in either the NYCity or Philadelphia areas including all commuter lines, Amtrak, subways, light rail and trolleys, bus and ferries when warranted. No fees, just let us know you want to join the ride and pay your fares. Ask to be on our email list or find us on FB as RIDEWITHMEHENRY (all caps) to get descriptions of each outing.
dehusmanWe had a cut of brand new, first trip cars (revenue empties from builder to owner) involved in a derailment and we timed the emergency brake application as holding the cars for less than 1 minute. before they bled off.
You have cited many details which I understand, but I do not exactly follow what points you are making with those details. I agree that once the train ran away, there was nothing that the brakes could have done to avoid the wreck, no matter whether they were ECP brakes or conventional air brakes.
You mention a case where brakes in emergency bled off in less than one minute. First, I am greatly surprised that it could leak off that fast. You must have heard compressed air leaking loudly in a major flow of leakage in order for the cylinders and reservoir to lose their pressure in one minute. I cannot imagine that losing the emergency application in one minute would be anything other than a major defect, rather than just part of normal variation.
If a train went into emergency on a grade and stopped; and then the application leaked off in one minute; the train would run away. Many have commented that their experience is that an emergency application would be expected to hold for many hours minimum, and maybe many days. Of course a small number of cars in the cut might leak down faster than the rest, but still leave enough set to hold the cut. So I am perplexed by your example of finding new cars that leaked off an emergency application in one minute.
If a cut leaked off the emergency application in one minute, that would mean that each car had that major defect of leakage, which further seems implausible.
I also do not understand why you are making a point about an emergency application leaking off, together with a point about the trainline leaking off. With brakes left in emergency, the trainline is 100% exhausted, so there is nothing to leak off. What would cause an emergency application to release would be the leaking off of the reservoir and brake cylinder; not a leaking off of the trainline.
However, aside from this issue of an emergency application leaking off: As I understand it, the Lac Megantic train was not left with an emergency application. It was left with a service application.
The assumption is that the shutdown of the engine and loss of air pumping caused the brakes to release from the service application. This is the point that I do not understand even though I have carefully read at least 50 explanations by people who seem to know the answer. If the compressor stopped pumping and leakage was not made up for, what leaks down? I know trainlines always have leakage, but would a leak down of the trainline with brakes in service application cause the brakes to release? I would like a simple answer to that question.
Or—was the leak-down from the cylinders holding the service application?
Another explanation was that a slight trainline pressure rise triggered a full brake release. If so, how would a loss of air pumping cause a slight trainline pressure rise?
These are the elements that I said I don’t understand when I was referencing the effect that ECP brakes would have had at Lac Megantic. But my point was that if a slight trainline pressure rise caused a full release, I suspect that this could not have occurred with ECP brakes because they are not controlled though trainline pressure. I am also not sure how ECP brakes would have been left during the tie up. And also, perhaps they will not leak down an emergency set as readily as would be the case with conventional air brakes.
However, in the very largest perspective: I am not even suggesting that ECP brakes would aid in securing a train because the rules would not allow it in the first place. Basically, overall, my response is to your point that braking improvements are worthless because you can cite a couple wrecks where braking would not have helped, despite the fact that it would help in many types of derailments. The Secretary of Transportation agrees with this point. So I predict that ECP brakes will become mandatory for oil trains.
henry6dehusman Just remember not all crude is the same, the ONLY crude that has had problems is the Bakken crude. The crude from every other formation that railroads have been hauling for over a century does NOT have those same problems. There is also a problem with Congress and the FRA just throwing solutions out there just because they are cool and high tech without thinking about whether they would have solved a problem. ECP wouldn't have prevented Lac Megantic, it wouldn't have prevented Casselton, it wouldn't have prevented the release in Kentucky. Correct. Not all crude is Bakken. But the railroads have to protect themselves and be protected from oil and gas shippers who mislabel or otherwise lie about the product being shipped. The integrity of these energy companies are in question at the moment and their belligerence overwhelmingly disregards and disrespects railroads, other private enterprises, and the public's safety and well being. Yes, I can point fingers and name names but that would be political and politics are not allowed to be discussed to that degree here. Not revealing the volatility and instability of Bakken crude to the railroads or to first responder emergency groups is a blatant example of what I am saying and not some made up conjecture.
dehusman Just remember not all crude is the same, the ONLY crude that has had problems is the Bakken crude. The crude from every other formation that railroads have been hauling for over a century does NOT have those same problems. There is also a problem with Congress and the FRA just throwing solutions out there just because they are cool and high tech without thinking about whether they would have solved a problem. ECP wouldn't have prevented Lac Megantic, it wouldn't have prevented Casselton, it wouldn't have prevented the release in Kentucky.
Just remember not all crude is the same, the ONLY crude that has had problems is the Bakken crude. The crude from every other formation that railroads have been hauling for over a century does NOT have those same problems.
There is also a problem with Congress and the FRA just throwing solutions out there just because they are cool and high tech without thinking about whether they would have solved a problem. ECP wouldn't have prevented Lac Megantic, it wouldn't have prevented Casselton, it wouldn't have prevented the release in Kentucky.
Dude,
What is your problem?
Did you get screwed in a well lease or what?
23 17 46 11
Euclid I do not conclude that because Locomotives were shut down, ECP or not, same thing would have happened. You may be right about that, but ECP brakes are charged and controlled differently.
I do not conclude that because Locomotives were shut down, ECP or not, same thing would have happened. You may be right about that, but ECP brakes are charged and controlled differently.
No engineer means nobody to place the brake handle in a position that would apply the brakes.
The train line wasn't compromised until the actual derailment so there was nothing to cause the train to go in emergency.
If the engines were shut down and the train line bled off then there was no air pressure in the system to apply the brakes.
Doesn't matter what the control method was, electronic or pneumatic, the first two are absolutely true. The third thing is subject to speculation and is independent of the control type, all brake systems using a train line have leaks in them, some take hours to bleed off, some take minutes. We had a cut of brand new, first trip cars (revenue empties from builder to owner) involved in a derailment and we timed the emergency brake application as holding the cars for less than 1 minute. before they bled off. YMMV.
We went through this whole scenario back in the 1970's with LPG cars. It didn't take any exotic brake system or dedicated equipment, all it took was building a better tank on the tank car. LPG is way more dangerous, way more explosive, way more volatile than any crude including Bakken. If it fixed the LPG problem, it can fix the crude problem.
OFF TOPIC, WARNING. NOT RAILROAD RELATED. RAILROAD RELATED POST COMING LATER.
Much of what is in the Atlantic article is the typical P.R. that the "garage sized" and "innovative" entrepreneurial companies / nonprofits are pushing in order to get their fairly radical and not commercially built designs funded and then eventually built. The stuff from UCS is their typical anti-nuclear spew. The article is pretty long for what most folks would like to read, but then again I'd like to think we're increasing our attention spans on average as a society, not decreasing them.
Short reply: There is always a need for, and benefit from, design innovation. However, the diesel locomotive became a practical reality in the 1920's, and it took until the end of the 1950's to push out steam here in the USA after years of practical experience, many further improvements in diesel locomotives, and much data gathering; these new reactors (like all reactors) will take more years than that, and they're starting from a practical standstill with little funding and no interest on the part of utilities that would eventually buy and operate commercialized designs. The ideas fronted under the headings "solutions" are correct, except that I need to point out that light water cooled reactors -- and specifically pressurized water reactors -- are dominating the massive and rapid nuclear build-out ongoing in South Korea, China and elsewhere, not radical designs or even older tested designs (like gas cooled reactors.) This can and should be expected for the foreseeable future.
Light water SMR's have already been built, successfully operated, and proven. This began in the late 1960's with the German-built nuclear powered ship Otto Hahn, first to use what we call an iPWR or integral pressurized water reactor. Their technical viability is not in question; the economics are bad for SMR nuclear plants that are built the same way gigantic 1000 - 1700 MW nuclear plants are. The entire plant needs to be designed innovatively; this is why NuScale Power has won the second DOE fund allocation for development. The demand for such plants is in question in some places (USA, Korea) but they're being built already in others (Russia, Argentina.)
The section describing Three Mile Island is entirely exactly correct. There's also a very keen observation about containment and new plants built to operate at atmospheric pressure that's right on... but adding to that, there is no need to wonder whether or not this would be required. Many years ago an organic cooled reactor was ordered under an AEC program to be built in the city of Piqua, Ohio. This was originally designed with no containment. AEC, after referral from the ACRS (Advisory Committee on Reactor Safeguards) ordered a conventional nuclear plant containment be built because of the proximity to populated areas, which was exactly how the plant was built. The plant is still there today, with fuel removed and in a condition we call SAFSTOR or Safe Storage awaiting dismantlement sometime in the future. It's right along the river on the east bank; you can find it quite easily using Bing maps or some such.
The railroaders might find the industry responses briefly mentioned about Fukushima Daiichi in this article to be of some interest relative to the Mac-Legantic rail accident, but I have some observations to write here later that might help sharpen the focus to see what each can learn from the other.
-Will Davis
Railroad Locomotives - My Blog
A quick check on posts suggests the need for a uniform policy on safety with a stopped and shut down Bakken train. There are several different opinions expressed on here as to the proper procedures.
C&NW, CA&E, MILW, CGW and IC fan
zugmann EuclidWhatever caused it, I wonder if that same cause would be possible with ECP brakes. ??? Locomotives were shut down. ECP or not, same thing would have happened.
EuclidWhatever caused it, I wonder if that same cause would be possible with ECP brakes.
???
Locomotives were shut down. ECP or not, same thing would have happened.
I said this: “But I do not know for sure how that would have played out. We still don't know exactly how the air brakes released on that train. Whatever caused it, I wonder if that same cause would be possible with ECP brakes.”
I do not conclude that because Locomotives were shut down, ECP or not, same thing would have happened. You may be right about that, but ECP brakes are charged and controlled differently. To determine if the engine shutdown would have cause the same release scenario with ECP brakes, I would have to know exactly why the brakes released in less than an hour after the engine was shut down. And then I would have to see whether that would happen with ECP brakes.
Will Davis I'm watching this string with extreme interest; you see, I'm in the nuclear field, and this rail accident is one of those watershed events like Three Mile Island, Chernobyl or Fukushima Daiichi. It's an event that is easily going to have permanent repurcussions industry-wide. How the industry centrally responds (AAR), individually responds (each railroad) and how the Federal government and public have responded seem so far quite as I could have expected, with the pleasant exception that the general public isn't calling for the wholesale abandonment of crude oil shipments, tank cars, or railroads. I've bookmarked the AAR response and I will to compare it to how the Nuclear Energy Institute has been responding to Fukushima Daiichi in order to see if there are interesting parallels. Perhaps we can learn something 'bigger picture' by studying both; we shall see. One thing is clear: The spotlight is on, as we say, and it won't go off soon. There will have to be credible responses to equipment conditions, and to the risk (both real and perceived) to populated areas, before it dims any. -Will Davis
I'm watching this string with extreme interest; you see, I'm in the nuclear field, and this rail accident is one of those watershed events like Three Mile Island, Chernobyl or Fukushima Daiichi. It's an event that is easily going to have permanent repurcussions industry-wide.
How the industry centrally responds (AAR), individually responds (each railroad) and how the Federal government and public have responded seem so far quite as I could have expected, with the pleasant exception that the general public isn't calling for the wholesale abandonment of crude oil shipments, tank cars, or railroads.
I've bookmarked the AAR response and I will to compare it to how the Nuclear Energy Institute has been responding to Fukushima Daiichi in order to see if there are interesting parallels. Perhaps we can learn something 'bigger picture' by studying both; we shall see.
One thing is clear: The spotlight is on, as we say, and it won't go off soon. There will have to be credible responses to equipment conditions, and to the risk (both real and perceived) to populated areas, before it dims any.
As you are knowledgeable about the nuclear energy industry, your comments on this long article would be useful:
http://www.theatlantic.com/technology/archive/2014/06/is-nuclear-power-ever-coming-back/373315/
henry6he oil companies have to provide the proper vessel for transporting and inform the railroad and first responders in order to assure as safe a trip and shipment as possible. It is their duty and responsibility as citizens.
And the oil companies will counter with "the cars are fine if the railroad would stop crashing them!"
The circle continues.
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
henry6 Correct. Not all crude is Bakken. But the railroads have to protect themselves and be protected from oil and gas shippers who mislabel or otherwise lie about the product being shipped.
But the shippers aren't "lying" to the extent that it would change how the railroads transport the crude. The brouhaha about mislabeling is of interest to the responders and the regulators, but if they had labeled it correctly it would not have made a single difference in how the product was transported.
The plain fact of the matter is you don't want ANY oil train derailments, even if the stuff doesn't go "boom" like Bakken crude. Any way you look at it it makes a helluva mess to clean up.
dehusmanJust remember not all crude is the same, the ONLY crude that has had problems is the Bakken crude. The crude from every other formation that railroads have been hauling for over a century does NOT have those same problems. There is also a problem with Congress and the FRA just throwing solutions out there just because they are cool and high tech without thinking about whether they would have solved a problem. ECP wouldn't have prevented Lac Megantic, it wouldn't have prevented Casselton, it wouldn't have prevented the release in Kentucky.
I agree that Bakken oil is posing the problem, and by "oil by rail," I meant to refer only to Bakken. ECP can prevent derailments by reducing in-train braking forces. Compared to conventional air brakes, ECP can also reduce the damge once a derailment occurs by dissipating the kinetic energy quicker due to its simultaneous application.
So, ECP would not have prevented the Casselton collision, but it might have reduced the damage.
ECP would not have prevented the derailment at Lac Megantic, and it would not have prevented any damage once the derailment occurred. However, it might have prevented the runaway in the first place. But I do not know for sure how that would have played out. We still don't know excactly how the air brakes released on that train. Whatever caused it, I wonder if that same cause would be possible with ECP brakes.
In any case, there should not have been any reliance on air brakes to hold the train, and that would also apply to ECP brakes.
Euclid I predict that when the dust all settles, oil by rail will be handled in highly specialized trains that will be a departure from conventional interchangeable, loose-car railroading. These trains will have ECP brakes, specialized couplers without slack and no draft gear. They will also have single control, pneumatically powered brake locks to secure the train with all brakes set fully and mechanically locked in the set condition. If they retain hand brakes, the hand brakes will not be used for securement. The brakes will be locked into full set, and no push-pull test will be needed to verify the securement.
I predict that when the dust all settles, oil by rail will be handled in highly specialized trains that will be a departure from conventional interchangeable, loose-car railroading. These trains will have ECP brakes, specialized couplers without slack and no draft gear. They will also have single control, pneumatically powered brake locks to secure the train with all brakes set fully and mechanically locked in the set condition. If they retain hand brakes, the hand brakes will not be used for securement. The brakes will be locked into full set, and no push-pull test will be needed to verify the securement.
RRKen Randy Stahl That's the PERFECT setup for a vandal or terrorist leaving a train in emergency. All you gotta do is pull some bleed rods and the train is gone... with NO chance of stopping it even if the train separates. NO thanks, I'd rather have the train fully charged. Pull some bleed rods? How is that going to release the whole train? And if the train is on air, and separates, it will still dump the cars. Why? Because if the air is still running, the self maintaining feature on the Automatic Brake Valve will keep the line charged to it's last state. So no matter how many times you pull the bleed rod, the car valve will sense the brake pipe pressure, and charge the EMG reservior back up to at least the pressure of the BP. If the train is off air, then of course there is concern, however, if there is no brake pipe pressure involved, then you are a fool for thinking even emergency application will hold it. Secure! Test! Set Air!
Randy Stahl That's the PERFECT setup for a vandal or terrorist leaving a train in emergency. All you gotta do is pull some bleed rods and the train is gone... with NO chance of stopping it even if the train separates. NO thanks, I'd rather have the train fully charged.
That's the PERFECT setup for a vandal or terrorist leaving a train in emergency. All you gotta do is pull some bleed rods and the train is gone... with NO chance of stopping it even if the train separates. NO thanks, I'd rather have the train fully charged.
Pull some bleed rods? How is that going to release the whole train?
And if the train is on air, and separates, it will still dump the cars. Why? Because if the air is still running, the self maintaining feature on the Automatic Brake Valve will keep the line charged to it's last state. So no matter how many times you pull the bleed rod, the car valve will sense the brake pipe pressure, and charge the EMG reservior back up to at least the pressure of the BP.
If the train is off air, then of course there is concern, however, if there is no brake pipe pressure involved, then you are a fool for thinking even emergency application will hold it.
Secure! Test! Set Air!
No, if the train is left in EMERGENCY , it is off air. If you pull enough (all) bleed rods the brakes will release, . The train isn't going to go into emergency again until the brakes are recharged.
I agree.. Secure and test. service reduction.
zugmann And in what part of c102 do you dump the train? My point is the one response to dump, then tie down the train. If you apply proper handbrakeage and do a proper 102 test, you don't need to dump the train. And you shouldn't. The whole point of the test is to make sure handbrakes only can hold said cut of cars. So many people over-analyze and over-think these things.
And in what part of c102 do you dump the train?
My point is the one response to dump, then tie down the train. If you apply proper handbrakeage and do a proper 102 test, you don't need to dump the train. And you shouldn't. The whole point of the test is to make sure handbrakes only can hold said cut of cars.
So many people over-analyze and over-think these things.
True, the C-102 doesn't call for the air to be dumped. However, if it does, you have to wait longer for the cars to recharge and brakes release to comply with the rule and make sure the cars stay there. Many times on a steep grade I have had conductors ask for the air to be knocked down on cars being set off (not cutting away from the entire train) in order to get a better hand brake on the cars, then complete the C-102 test.
Whether or not the air gets dumps is really a moot point. When you cut away from the cars, the air gets dumped anyway.
That's why couplers are absolutely necessary. You're not going to shop a whole train because one car has a bad brake/wheel/defect. You'll set that car out and continue on.
What if I need to set out a shop with air brake issues?
zugmann EuclidThey will also have single control, pneumatically powered brake locks to secure the train with all brakes set fully and mechanically locked in the set condition. Isn't that what a handbrake basically is?
EuclidThey will also have single control, pneumatically powered brake locks to secure the train with all brakes set fully and mechanically locked in the set condition.
Isn't that what a handbrake basically is?
I am referring to one control lever in the cab that will activate a pneumatically powered mechanical lock simultaneously on every car in the train after the air brakes are fully set. After that, if the air brakes happen to release, the brake rigging and shoes will remain fully applied due to the mechanical lock.
It has nothing to do with handbrakes. You could take the handbrakes off and throw them away, but you might want to keep them for sentimental reasons.
If we go the ECP route, I think cars will eventually get push-button handbrakes like many locomotives have. One button, and you have 100% handbrakes set. But there will probably always be a manual override on cars. Electronics fail.
Unless you change the whole air brake thing, ala roadrailer.
ECP brakes will set simultaneously, and thus will reduce in-train braking forces that can cause derailments. If a train derails, ECP brakes will dissipate the kinetic energy faster than conventional air brakes because ECP brakes set simultaneously. The quicker dissipation of kinetic energy will leave less time for that energy to damage tank cars.
zugmannHow do you test effectiveness of handbrakes when the train is in the hole?
It's called Rule C-102. Go look it up in the NS-1.
That's where the importance of a proper handbrake test comes in. As stated, you pull enough bleed rods and only the handbrakes will be holding the train. There's one place where I have to leave cars on ground air and its on a hill, and at the bottom is an interlocking with NS. 2 handbrakes will hold an empty coal train and needless to say at this location I apply 3.
Our community is FREE to join. To participate you must either login or register for an account.