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QUOTE: Interesting how that knuckle stays in without a pin, isn't it. But I've always thought that without a pin, the stress factors of normal slack action would have to take that knuckle out sooner or later, a personal theory.
QUOTE: Originally posted by macguy An interesting tidbit for those out there that didn't already know it.... If the knuckle is closed, you don't have to have a pin to hold it in there, the only time you really need a pin is when you open the knuckle up. I never knew that until I opened a knuckle one time and it came tumbling out, whoever replaced it just didn't bother putting another pin in.
QUOTE: Originally posted by zardoz Originally posted by macguy An interesting tidbit for those out there that didn't already know it.... If the knuckle is closed, you don't have to have a pin to hold it in there, the only time you really need a pin is when you open the knuckle up. I never knew that until I opened a knuckle one time and it came tumbling out, whoever replaced it just didn't bother putting another pin in. "Pins falling out of knuckles happens quite frequently on coal cars that are dumped in a rotary dumper that turns the car almost completely upside down. The coal plant at Waukegan was famous for that. They would shove the cars one at a time up to the dumping hill, turn it over to dump the coal, then let it roll down the hill to the yard. And to make matters worse, their yard was ten curved tracks, so there were very many bypassed drawbars, as well as frozen knuckles". The knuckle pins on open top cars that may be turned over are supposed to have cotter pins installed to prevent this from happening. Many people have been injured by having knuckles fall on their feet. Reply csxengineer98 Member sinceOctober 2002 From: US 2,358 posts Posted by csxengineer98 on Thursday, October 28, 2004 2:52 PM little trick when you replace a broken knuckle...once you get the cottor key out of the kingpin..and befor you pull it out...lift up on the cut leaver and get something to wedge in to hold it up...the chissel or a hunk of wood..anything to keep it from falling down agin... becouse if the leaver falls out when you take the old knucle out...the guts of the coupler will fall out of place..and its a real pain in the *** to put it all back in right.... so by wedging the cutleaver up..you keep them from all falling out when you pull the broken one.... then its just a matter of putting the new in in..putting the kingpin back in..and pulling out the wedge...and you should be set!!!! csx engineer "I AM the higher source" Keep the wheels on steel Reply Anonymous Member sinceApril 2003 305,205 posts Posted by Anonymous on Thursday, October 28, 2004 3:19 PM I wonder how much the presence of slack in the coupler causes pins/knuckles to fail. The slack causes wave to travel along the train when it brakes which, I imagine, causes most of the fatigue to the couplers. Would it be so hard to start a train if there was no slack action? Reply Edit Anonymous Member sinceApril 2003 305,205 posts Posted by Anonymous on Thursday, October 28, 2004 4:16 PM I've seen engineers use slack to get a heavy train started and I have found it helpful in the yard using the Remote engines to do the same thing when I'm pulling 60 loaded grain cars with two GP-38's. And then one time I couldn't get a track to move at all, I tried bunching the slack and then pulling and got nothing. I finally decided just to check to make sure both engines were online and sure enough one wasn't. So, when things don't work, I've discovered looking for the obvious can actually be beneficial. Reply Edit Anonymous Member sinceApril 2003 305,205 posts Posted by Anonymous on Thursday, October 28, 2004 4:41 PM thank you mr Hemphill :) The wave on the slack is more about stressing metal - thus increasing the chance of sheering a pin/breaking something 1. I assume that can happen only with a train fully streched out. (eg - no or very little slack)? 2/3. Now - wouldn't a fixed/rigid train be less suspectible for this kind of occurance? After all there would be no dynamic component (slack wave) making it possible for the couplers to momentary exceed coupler strength 4. Once again - with no slack partially released train will not move a foot. Thus it would be much less probable to break the train this way. jchnhtfd: I was under an impression that as long as the plastic deformation limit was not exceeded steel does not fatigue break. Unlike aluminum for instance. The only way for steel to bend/break is to either exceed its yield/sheer strength (like in impact or meterial defect). Reply Edit edblysard Member sinceMarch 2002 9,265 posts Posted by edblysard on Thursday, October 28, 2004 6:43 PM Jamie, Think about switching... flat yard or hump. I forget to open the knuckle on the car I am kicking. Not normal, but it happens. If your lucky, when you kick the car into the last car you put in a track, the knuckles dont by-pass, they just stay bald headed. But the forces involved are huge, and any weak part in the coupler will give a little more. Any defects in knuckle will get worst, and the knuckle pin will get a pretty good hammering. Closed, there is a small amount of play in the knuckle. The pin holds nothing in place when the knuckle is closed, but the knuckle can compress enough to apply some of the forces on the pin. They can shear in two, or bend. Depending on how old it is, and how beat up it is, they just crap out. All the pin does is provide a pivot point for the knuckle to turn on when you open it, but it does take some stress. If you get the chance to do so safely, walk a switching yard track. You find pieces of pins all over the place, a few inches of the top of a pin, or just the body of it, minus the top lip. You might even find one of the rubber/hard plastic pins... Seen knuckles with the face shattered, or the shoulder torn off.... There is a limit to what these things can, and can't take. Any defect cast into the kuckle will, some where at some time, will fail, either in switching, or out on the road. If you have ever looked inside a coupler/knuckle, its pretty simple, which is why they work so well, and take the beating they do. But, like any piece of equipment that takes rough handleing, they get beat up pretty good. Bang it around enough, it will break. Ed 23 17 46 11 Reply tree68 Member sinceDecember 2001 From: Northern New York 25,006 posts Posted by tree68 on Thursday, October 28, 2004 8:27 PM There is an interesting picture of a "knuckle garden" on Ed Krug's Photo Essay Site. Not a lot of detail, but you can see the variety of failures... 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... Reply Anonymous Member sinceApril 2003 305,205 posts Posted by Anonymous on Thursday, October 28, 2004 8:31 PM QUOTE: Originally posted by tree68 There is an interesting picture of a "knuckle garden" on Ed Krug's Photo Essay Site. Not a lot of detail, but you can see the variety of failures... Just a note to the Krug fans out here, he's added a few more photo essays recently... I always find what he has to say interesting. Reply Edit csxengineer98 Member sinceOctober 2002 From: US 2,358 posts Posted by csxengineer98 on Friday, October 29, 2004 3:39 AM QUOTE: Originally posted by tree68 There is an interesting picture of a "knuckle garden" on Ed Krug's Photo Essay Site. Not a lot of detail, but you can see the variety of failures... check out his essays on tonnage and tractive effort...gives you a very very very good overview of the stresses that a coupler goes through..not to mention all the mathimatical eqautions that go alot with figering it out...very good stuff... csx engineer "I AM the higher source" Keep the wheels on steel Reply MP173 Member sinceMay 2004 From: Valparaiso, In 5,921 posts Posted by MP173 on Friday, October 29, 2004 7:45 AM Ed Krug's site is quite the place! He mixes photography, writing, and knowledge very well. Very well. ed Reply Mookie Member sinceJune 2001 From: US 13,488 posts Posted by Mookie on Friday, October 29, 2004 8:23 AM Is there ever a time when you would just need a pin and do they carry these on the engine as well? She who has no signature! cinscocom-tmw Reply zardoz Member sinceJanuary 2003 From: Kenosha, WI 6,567 posts Posted by zardoz on Friday, October 29, 2004 8:25 AM That's why when pulling (without a DPU) a very heavy train up and over a steep hill the engineer will begin to reduce the throttle when starting downhill, even though the train may be nowhere near the speed it is allowed. Otherwise, the pull of the locomotives, plus the additional power of gravity pulling on the head end, can cause a knuckle failure even though the train is experiencing zero slack action. For analogy, consider a weight attached to one end of a string, and pulling that string from the non-weighted end over a knife. Reply UP_North Member sinceJuly 2004 From: chicagoland 48 posts Posted by UP_North on Friday, October 29, 2004 1:10 PM Being one that has to pull and spot the Waukegan power plant regularly, I will agree with zardoz that it is one hell of a place to have to put a train together. Having to make joints in curves, and screwed up couplers are only a couple of problems that are faced there. A small correction though, the yard tracks actually slope away from the dumper, so one has to be careful that cars that don't hook up don't come rolling back at you. Another thing I don't think anyone has mentioned is that many coupler pins in coal cars are plastic with spring clips at the bottom to keep them secure. Power plants have found out they are less damaging to the crushers and furnaces. On to changing knuckles. First pull out the knuckle pin (sometimes easy, sometimes hard), then raise the cut lever and pull out whats left of the knuckle. Now the tricky part. Without dropping the cut lever and with the guts still pulled up, reach around to the inside where the knuckle was sitting. along the bottom of the coupler is a hook shaped piece that helps pull the guts up when the knuckle is opened. Pull back towards yourself as you slowly lower the cut lever and bingo, no need to prop up, tie up or hold up the cut lever, it stays up. Now pick up the new knuckle, place it in the coupler, lining up the pin hole first and slam it closed. Finally replace the knuckle pin and highball. Of course all of this can be done in about 30 seconds or so. It takes more time to talk about it than actually do it. Ihope I didn't confuse anyone to much Reply zardoz Member sinceJanuary 2003 From: Kenosha, WI 6,567 posts Posted by zardoz on Friday, October 29, 2004 2:30 PM QUOTE: Originally posted by UP_North Being one that has to pull and spot the Waukegan power plant regularly, I will agree with zardoz that it is one hell of a place to have to put a train together. Having to make joints in curves, and screwed up couplers are only a couple of problems that are faced there. A small correction though, the yard tracks actually slope away from the dumper, so one has to be careful that cars that don't hook up don't come rolling back at you. Well, it has been 20 years since I was there.....at least as a groundpounder. But that was the trick, though; to get the cars to roll enough to seperate them, but not too much that they didn't run out to foul. Much better (or at least safer) to do it by the book. Reply jchnhtfd Member sinceJanuary 2001 From: US 1,537 posts Posted by jchnhtfd on Friday, October 29, 2004 2:31 PM QUOTE: Originally posted by uzurpator ... jchnhtfd: I was under an impression that as long as the plastic deformation limit was not exceeded steel does not fatigue break. Unlike aluminum for instance. The only way for steel to bend/break is to either exceed its yield/sheer strength (like in impact or meterial defect). That's the theory... in truth, it's true in principle for any metal (as long as the metal is in the elastic range, it shouldn't fatigue). That being said...[:)] there are a few things to be cautious about, and the most serious is the presence of material variations in the body of the knuckle: changes in the type of steel, for instance (tempering differences, etc.) can change the stress distribution and push some volumes over the yield point; and the presence of stress risers in the knuckle -- which can be any sharp change in section, or a knick in the side, or... again, raising the local stress over the critical point. And, of course, once a fatigue failure starts, the stress is more concentrated, and so the crack propagates and, so the stress concentrates, and...[:D]. Does all this take slack action to happen? No -- just variations in drawbar pull. Granted, shock (like a bad slack action) doesn't help a bit, and may be the immediate trigger, but and variation in stress will do it![:D] Jamie Reply Anonymous Member sinceApril 2003 305,205 posts Posted by Anonymous on Friday, October 29, 2004 3:45 PM I think the hardest part of changing a knuckle is getting the blasted cotter pin out so you can pullout the pivot pin. Reply Edit mvlandsw Member sinceDecember 2001 1,189 posts Posted by mvlandsw on Friday, October 29, 2004 11:30 PM QUOTE: Originally posted by drailed1999 I think the hardest part of changing a knuckle is getting the blasted cotter pin out so you can pullout the pivot pin. Just cut it off with your hammer and chiesel. Reply ValleyX Member sinceApril 2001 From: US 1,103 posts Posted by ValleyX on Saturday, October 30, 2004 10:05 AM Mookie, there should be replacement knucklepins in the toolbox, if the toolbox is well supplied, as well as cotterkeys. Cresting the hill with a heavy train by reducing the throttle is a good practice when handling trains. I've always found that if you get the engines over the crest of the grade, the rest of the train will always come, and never had this disproved by failing to make the grade. Reply Anonymous Member sinceApril 2003 305,205 posts Posted by Anonymous on Saturday, October 30, 2004 12:03 PM QUOTE: Originally posted by mvlandsw QUOTE: Originally posted by drailed1999 I think the hardest part of changing a knuckle is getting the blasted cotter pin out so you can pullout the pivot pin. Just cut it off with your hammer and chiesel. Chisel !!! We didn't have any stinking chisels. They were all stolen out of all the locos and we had no replacements. Reply Edit csxengineer98 Member sinceOctober 2002 From: US 2,358 posts Posted by csxengineer98 on Monday, November 1, 2004 2:25 AM QUOTE: Originally posted by drailed1999 QUOTE: Originally posted by mvlandsw QUOTE: Originally posted by drailed1999 I think the hardest part of changing a knuckle is getting the blasted cotter pin out so you can pullout the pivot pin. Just cut it off with your hammer and chiesel. Chisel !!! We didn't have any stinking chisels. They were all stolen out of all the locos and we had no replacements. spikes work in a pinch csx engineer "I AM the higher source" Keep the wheels on steel Reply Join our Community! Our community is FREE to join. To participate you must either login or register for an account. 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Originally posted by macguy An interesting tidbit for those out there that didn't already know it.... If the knuckle is closed, you don't have to have a pin to hold it in there, the only time you really need a pin is when you open the knuckle up. I never knew that until I opened a knuckle one time and it came tumbling out, whoever replaced it just didn't bother putting another pin in.
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...
QUOTE: Originally posted by tree68 There is an interesting picture of a "knuckle garden" on Ed Krug's Photo Essay Site. Not a lot of detail, but you can see the variety of failures...
She who has no signature! cinscocom-tmw
QUOTE: Originally posted by UP_North Being one that has to pull and spot the Waukegan power plant regularly, I will agree with zardoz that it is one hell of a place to have to put a train together. Having to make joints in curves, and screwed up couplers are only a couple of problems that are faced there. A small correction though, the yard tracks actually slope away from the dumper, so one has to be careful that cars that don't hook up don't come rolling back at you.
QUOTE: Originally posted by uzurpator ... jchnhtfd: I was under an impression that as long as the plastic deformation limit was not exceeded steel does not fatigue break. Unlike aluminum for instance. The only way for steel to bend/break is to either exceed its yield/sheer strength (like in impact or meterial defect).
QUOTE: Originally posted by drailed1999 I think the hardest part of changing a knuckle is getting the blasted cotter pin out so you can pullout the pivot pin.
QUOTE: Originally posted by mvlandsw QUOTE: Originally posted by drailed1999 I think the hardest part of changing a knuckle is getting the blasted cotter pin out so you can pullout the pivot pin. Just cut it off with your hammer and chiesel.
QUOTE: Originally posted by drailed1999 QUOTE: Originally posted by mvlandsw QUOTE: Originally posted by drailed1999 I think the hardest part of changing a knuckle is getting the blasted cotter pin out so you can pullout the pivot pin. Just cut it off with your hammer and chiesel. Chisel !!! We didn't have any stinking chisels. They were all stolen out of all the locos and we had no replacements.
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