I often read about a train pulling a drawbar. I take this to mean that the coupler and drawbar are pulled right out of the car.
What, exactly, breaks to cause a pulled drawbar? A pin? Do engines carry spare pins, so that the crew can affect a repair? Or does the crew always have to set the car out?
If the car must be set out, how is this done. How do you handle a car without a coupler/drawbar? In the maneuvering of the defective car, does the adjacent car/engine often get damaged?
My impression is that changing broken couplers is a not-uncommon part of the job. Do engines always carry spare knuckles? If so, where on the engine?
Please give me the low-down on all of this.
Still in training.
A pulled drawbar involves some pretty heavy hardware. I don't know how they are secured, either, but I doubt it's something that's going to get fixed by the crew in the field.
Odds are someone with a heavy chain will be called upon to supply same if the pulled drawbar is on the "wrong" end of the car. If it's on the "right" end, the brakes can be cut out and the car pulled to someplace it can be set out.
If it is on the "wrong" end, and there's a DPU involved, they might be able to pull it back.
You'll often see a knuckle on a "spike" on the walkway behind the cab. They could also be in the nose of the locomotive. Replacing a broken knuckle isn't difficult - the pin is usually held in by gravity. . Getting it where it needs to be could be more of a challenge - you wouldn't want to carry one the length of the train.
Many accounts I've seen involving changing a knuckle involve dropping the knuckle on the ballast and moving the train to position the offending coupler where it can be reached. Or dropping the knuckle, then pulling ahead so the conductor can prop the knuckle on the rear of the car with a good knuckle, then back the train to where it needs to be to effect the repair.
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...
There are multiple defects that get reported under the generalized defect of 'drawbar'. In some cases the shank of the drawbar does break in two. In other cases the pin that secures the drawbar to the body of the car breaks and the drawbar gets pulled out of the car. Another variety is where the 'carrier iron' that limits the lowest movement of the drawbar in relation to the level of the car, breaks and allows the drawbar to drop beneath the level where it can remain coupled to the adjacent car. The other thing to remember, drawbars have varying lengths. A standard 40 foot box or similar car may have a drawbar no more than about two feet long behind the coupler face. Auto racks and intermodal cars may have drawbars up to approximately eight feet long. Any of these drawbars are too heavy for normal men to handle without some form of power assist.
A drawbar out of the 'right' end of a car is where the motive power of the train can more the car to a set out location, normally without further mechanical assistance. A drawbar out of the 'wrong' end is where the car lacking the drawbar must either be chained up to engines/equipment moving in the train's movement direction, or power must be coupled to the rear of the train to affect the set out.
A drawbar that physically comes out of a car has the potential to bounce down on the track structure and either damaging the track or coming to rest on top of the track and creating a derailment.
Drawbars coming our of interlocking type couplers tend to stay coupled to the adjacent coupler. Powered equipment will be required to safely uncouple this drawbar and coupler.
Drawbar incidents 99.9% of the time cannot be totally resolved by the train crew without assistance.
Never too old to have a happy childhood!
BaltACDDrawbar incidents 99.9% of the time cannot be totally resolved by the train crew without assistance.
And I sure wouldn't want to mess with that .1% of crews that can.
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
Is the drawbar or the knuckle or the pins that hold them, the designated weak link to break so that more serious damage is avoided?
MidlandMikeIs the drawbar or the knuckle or the pins that hold them, the designated weak link to break so that more serious damage is avoided?
The knuckle is the designated weak link. Broken knuckles can be replaced by crews. Engines are normally equipped with two knuckles - a Type E and a Type F. The individual doing the inspection/replacement is supposed to recognize what type the broken one is an replace it accordingly. There is a 50% chance of getting it right, my experiences have indicted that the probability is closer to 100% in getting it wrong.
Whoever authorized two types of knuckles should take a long walk off a short plank into deep water.
MidlandMikeor the pins that hold them,
A closed knuckle will hold even if the pin is removed...
BaltACD MidlandMike Is the drawbar or the knuckle or the pins that hold them, the designated weak link to break so that more serious damage is avoided? The knuckle is the designated weak link. Broken knuckles can be replaced by crews. Engines are normally equipped with two knuckles - a Type E and a Type F. The individual doing the inspection/replacement is supposed to recognize what type the broken one is an replace it accordingly. There is a 50% chance of getting it right, my experiences have indicted that the probability is closer to 100% in getting it wrong. Whoever authorized two types of knuckles should take a long walk off a short plank into deep water.
MidlandMike Is the drawbar or the knuckle or the pins that hold them, the designated weak link to break so that more serious damage is avoided?
Often the problem is that the spare knuckles are kept on the locomotive's rear pilot in holders marked E and F. Now all would be well if when replacing these knuckles the E's woud be placed on the E holder and the F's in the F holder. Often this is not the case. So when a knuckle is needed, often the required knuckle is pulled from the marked holder without actually checking the type.
There a few ways to determine the type of knuckle needed. One is the serial number on the knuckle itself. They E or F in the series. https://www.wabteccorp.com/freight-car/end-of-car-systems/coupler-system/knuckles Another way is to look at the end part of the knuckle that locks inside the coupler. Using the illustrations in the provided link, the E has a rounded end, like a small "e". The F is flatter and the corners are more squared off, like the letter F. The type of draft gear is also stencilled somewhere on the car.
The F knuckle is a stronger draft gear, but more expensive. So F's usually are used on more specialized equipment, like rotary dump gondolas and hoppers. Most everything else uses an E.
The hardest part of changing out a knuckle for me was getting the cotter pin that held the knuckle pin in out. There are supposed to be some tools on the engines, but sometimes they are missing. I learned fast to supply myself with some basic, and heavy duty type, tools just in case.
Going back to drawbars, if it's a right ender, the crew only has to set out the damaged car, and maybe to locate the missing drawbar. That's fairly easy for crews to handle. (Finding a place to set out a car may be another manner with all the set out tracks that have been removed over time.) It's the wrong enders that cause the problems. Usually another train has to come up and use their engines to pull the wrong ender back to a set out location. If the damage isn't to severe, car men may repair it on the spot. Usually that doesn't happen.
I was told once about the E and F designations, and the placement of spares on the locomotive. The explanation may be true, or have been born by coincidence. In any case (and assuming it was true), what's the significance of E and F?
Jeff
Only open top cars that may be turned over to empty them are supposed to have cotter keys in the knuckle pin. Gravity holds others in place. A missing knuckle pin can be dangerous to the person who pulls the cut lever and has the knuckle fall out onto their foot.
When I worked in the Union Railroad car shop three men and a bar could replace a standard drawbar. Two would lift it with the bar while the third balanced and pushed it in.
A drawbar can come out without any damage to the parts. The crosskey that holds the drawbar in place has a retainer to keep the crosskey in place. If the retainer is missing for whatever reason the crosskey can work its way out leaving nothing to keep the drawbar in place.
mvlandswOnly open top cars that may be turned over to empty them are supposed to have cotter keys in the knuckle pin. Gravity holds others in place. A missing knuckle pin can be dangerous to the person who pulls the cut lever and has the knuckle fall out onto their foot.
There's some places tha tlike to put cotter pins on everything. Pain in the butt, but it does keep the pins from hopping out with hard couplings - so there's that.
And for the love of all that is Gevo, never put your foot under the coupler when opening the knuckle. Day 1 stuff there. Also look for a pin before opening a knuckle. Day 2. Although after many years you can usually feel if the pin is missing as you go to open a knuckle (if you forget your day 2 lessons).
Two spikes do a half decent job if you can't find a replacement knuckle pin.
CN still puts a heavy chain on each locomotive, and we are still expected to tow a wrong-side drawbar to the next backtrack if there is no better alternative. The end of the B/O car will get dented a bit when you push it into the backtrack, but the carmen already have to come to fix it and it's usually already been damaged when the drawbar broke or came out, so a few hundred feet of rough treatment doesn't really matter.
I'll have another look next time I'm out, but I'm pretty sure I've seen a few freight cars at the museum with 'D' couplers, and the drawbars on those are small enough that two or three strong men could probably replace one by hand.
Greetings from Alberta
-an Articulate Malcontent
I would hate to imagine how many knuckle pins B&O/Chessie/CSX have shipped overseas with the rotary car dumpers at both Curtis Bay Coal Piers and Newport News Coal Piers.
SD70DudeTwo spikes do a half decent job if you can't find a replacement knuckle pin.
Pull them both out at the same time or one will drop down and may get stuck.
tree68 MidlandMike or the pins that hold them, A closed knuckle will hold even if the pin is removed...
MidlandMike or the pins that hold them,
I thought raising the pin uncoupled the car?
MidlandMike tree68 MidlandMike or the pins that hold them, A closed knuckle will hold even if the pin is removed... I thought raising the pin uncoupled the car?
The knuckle pin has no effect in locking or unlocking a coupler knuckle. The knuckle pin ONLY positions the knuckle casting withing the coupler housing. The locking mechanism for the knuckle is in the center of the coupler housing. Most couplers these days have a underslung coupler lock that is operated by the cut lever.
BaltACD MidlandMike tree68 MidlandMike or the pins that hold them, A closed knuckle will hold even if the pin is removed... I thought raising the pin uncoupled the car? The knuckle pin has no effect in locking or unlocking a coupler knuckle. The knuckle pin ONLY positions the knuckle casting withing the coupler housing. The locking mechanism for the knuckle is in the center of the coupler housing. Most couplers these days have a underslung coupler lock that is operated by the cut lever.
I guess I was conflating the knuckle hinge pin with the coupler lock that I also thought was some kind of pin. Do they still use the expression "pull the pin".
MidlandMike BaltACD MidlandMike tree68 MidlandMike or the pins that hold them, A closed knuckle will hold even if the pin is removed... I thought raising the pin uncoupled the car? The knuckle pin has no effect in locking or unlocking a coupler knuckle. The knuckle pin ONLY positions the knuckle casting withing the coupler housing. The locking mechanism for the knuckle is in the center of the coupler housing. Most couplers these days have a underslung coupler lock that is operated by the cut lever. I guess I was conflating the knuckle hinge pin with the coupler lock that I also thought was some kind of pin. Do they still use the expression "pull the pin".
The expression is still used. I think, locomotive couplers still use a vertical knuckle locking pin. At least with my time in the field I know the yard engines that I worked with had the vertical coupler locking pin.
Is a drawbar inserted inside a hollow shaft of the coupler?
Or is the coupler shaft inserted inside a hollow portion of the drawbar?
Lithonia Operator Is a drawbar inserted inside a hollow shaft of the coupler? Or is the coupler shaft inserted inside a hollow portion of the drawbar?
Think of a trailer hitch receiver on a car or truck.
tree68 Lithonia Operator Is a drawbar inserted inside a hollow shaft of the coupler? Or is the coupler shaft inserted inside a hollow portion of the drawbar? Think of a trailer hitch receiver on a car or truck.
Except there is no pin that secures the drawbar into the pocket like there is on a trailer hitch receiver. It is more like an arrangement of wedges, and sometimes springs, that allow some movement but still restrict how far in or out the drawbar can go under normal conditions.
Most couplers assemblies are designed to have at least some fore and aft play in them to minimize shocks as slack goes in and out. Cars with so called "cushioned drawbars" have a lot of play, and the freight engineers will tell you lots of stories about how having them in a long train in the wrong spots can lead to all sorts of train handling fun.
I tried to find a decent diagram of a coupler, and this is the best one I could locate with a quick search. If you Google search for railroad coupler draft gear design, you might be able to find something better.
A picture (video)
https://www.youtube.com/watch?v=I2LNXKhDOAQ
The expression 'pulling the pin' is definitely still used. But the 'pin' it refers to would more accurately be called the 'locking block' (the thing that keeps the knuckle from swinging open).
Non-cushioned drawbars do have a pin to hold the drawbar in the car, it goes through the big round hole at the inside end of the drawbar.
Over the last half-century, usually with an older car, have seen cases where the Drawbars stayed 'in' the Car, but about 1/3 of Car separated from other 2/3 from top to bottom.
Thank You.
SD70Dude But the 'pin' it refers to would more accurately be called the 'locking block' (the thing that keeps the knuckle from swinging open).
Common advice when coupling cars - making sure the "pin" drops...
tree68 SD70Dude But the 'pin' it refers to would more accurately be called the 'locking block' (the thing that keeps the knuckle from swinging open). Common advice when coupling cars - making sure the "pin" drops...
Oh yes, I always watch for that and make sure to show new trainees how to tell if a joint made just by looking at it.
Sometimes the pin won't drop completely and it will pass the initial stretch test, but it will give way later when more force is applied, causing the knuckle to open. This has led to several incidents over the years.
https://www.bst-tsb.gc.ca/eng/rapports-reports/rail/2015/r15t0173/r15t0173.html
https://www.bst-tsb.gc.ca/eng/rapports-reports/rail/2018/R18Q0046/R18Q0046.html
https://www.bst-tsb.gc.ca/eng/rapports-reports/rail/2017/R17V0096/R17V0096.html
I'm sure there are more.
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