I have a question about uncoupling on grade. I just built a ~4 degree grade on my mainline. The problem with this 4 degree grade is that the locomotive often loses the passenger cars at the entrance of the grade. Here is what happened:
As the locomotive enters the grade, its body takes a ~4 degree angle and lowers down its rear coupler. Since at this time the passenger car is not in the grade, the coupler in the passenger car is higher than the locomotive’s coupler such that the bottom of the passenger car coupler barely couples with the top of the locomotive’s coupler. Also, as the locomotive enters the grade, it slows down a little bit, which causes the passenger to move forward relatively. This two things together cause uncoupling of the couplers and the loss of passenger cars.
Since it took me a while to build the grade and since my room space is limited, I am wondering if there is any method to fix this problem other than changing the grade to a smaller one. The locomotive I used is an AMD 103 from Athearn. The passenger car is Walther’s Budd 85’. I used the original couplers from the manufacturers. Would changing to some kind of Kadee’s coupler help? If yes, what kind of Kadee’s coupler should I use?
Thanks, Rick. Adding a transition grade might be a choice but I kind of not want to redo the trackwork unless it is the only choice. Do you have any other suggestions?
Rick’s right. You’ll need to provide more of a transition between the level track and the 4% grade. This is called a “vertical curve”. Depending on what the subroadbed is and how it’s supported by the benchwork, it may just be a matter of nudging things up a bit on what is now the level track before the start of the 4% grade.
The only other solution is to use shorter rolling stock, which may or may not work, depending on how sharp the transition between level track and the grade actually is.
Check you coupler heights against a Kadee height gauge to make absolutely certain that they are all correct, if one is a little high or low, it will amplify the problem. However, that is a very big change in your track work and I’m not sure that anything will solve the problem 100%.
What kind of subroadbed did you use? You may be able to simply use a riser right at the level to 4% location to bring the roadbed up just a tad to get a better transition.
I’m guessing here, but it sounds like you don’t have the scenery down yet. You did the right thing at testing now versus later. Hopefully it won’t be too painfull and you can make a quick repair.
I agree with the other posters, you need some sort of brief ‘transitional’ grade. And I’d also recommend that you replace the couplers in the Walthers cars with Kadees. The couplers supplied with the cars aren’t very sturdy and tend to pull apart on grades. Every time I buy a Walthers car (or Athearn, for that matter) I replace the couplers immediately.
I originally had the same problem as you. What I did was raise up the track prior to the grade angle, and stuffed a bunch of ballast under the tracks to form sort of a transistion to remove the sharp angle. I used real rocks under my rails. It worked fine that way, but later it was all torn up, and the whole thing re-done.
Unforseen consequences to those of us without the experience.
Unfortunately, couplers do not compensate for rough trackage. If your transition is too steep it is best to correct it or your are going to have constant problems regardless of what type or make of couplers you use. If you do not want to fix the track then you may have to run a short car between the loco and first long passenger car. Do you run the other direction, if so, does the uncoupling happen on the down transition? Is there an opposite transition to the upper level that brings the train back down and do you have problems there also or is it a more gradual slope? Do any of the passenger cars uncouple from each other or is it just the first car behind the locomotive?
Have you checked your coupler heights to make sure “all” of your couplers are at the “same” height? Make sure that there is no droop or slant to any of the couplers. The factory couplers are plastic and the plastic knuckles slip out of each other easier than a metal coupler. You might try our newer Kadee #148 whisker coupler and fine tune the coupler height and mounting level. It may or may not make a difference which depends on how severe your transition grade is.
Wow! Thank you all so much for so many valuable suggestions. I will do the following two things and will let you know: 1. Try to add a small transition zone so that the train will not jump into the grade suddenly; 2. Change the coupler and make sure they are well aligned. From what I saw from the suggestions, changing the coupler may not solve the problem, but it may help. Also, I am interested in Kadee’s Magnetic uncoupling (which can uncouple at the right time, not as what I have now. ).
Thanks for your suggestions about couplers. I have two questions that may not be related to my original question:
On Kadee website, it suggests that we use coupler 27 for AMD 103 and 26 or 46 for Walthers Budd. How do these compare with the new #148? I bet that 148 might be better, but can you kindly provide a short reason? Also, I am interested in Delayed Magnetic Uncoupling, can #148 work with it?
For coupler #26 or #46, the website says #46 is a metal coupler and but does not say so for #26. I guess #26 is not a metal coupler. What is the difference between a metal coupler and a non-metal coupler? Which one is better?
bigwall, did you ever have a car which was continually scraping its front bumper in a driveway; what was happening here was that the front bumper was trying to negotiate the driveway while your front axle was still trying to get out of the street. Roughly the same thing is happening here with your train.
Unless you do have some kind of a coupler mixmatch which is aggravating this situation you have two choices for eliminating your problem: you can, as has been suggested, tear out some of you trackwork and reconstruct it with a transition to grade - there was a topic on this very subject not too long ago right here on the forum
The AMD 103 that we have in our possession has #27 couplers on it. The Walthers Budd cars we have needed need the long shank #26/46 coupler to gain the clearance from under the diaphragms, however, some of these cars I have converted for others had clearance OK for a medium shank coupler like the #5 or our new #148 couplers. The #148 is easier to install, especially with the newer shallower draft gear boxes certain model makers are using now. The 20 and 30 series couplers are plastic with a metal knuckle (moving part of the coupler head). The 40 series coupler are all metal. All three series 20, 30, and 40 are the same dimensions for corresponding numbers since we use the same molds for the metal and plastic series couplers. We recommend not to have a metal to metal coupler mounting for insulation purposes especially if the coupler shank is in contact with the mounting surface. This is why we introduced the plastic 20 and 30 series couplers. Where appropriate we recommend the metal 40 series couplers over the 20 series.
If you have more questions along this regard please contact me directly at mail@kadee.com.
Hay Jerry:: I have been following your post and gained some good tips on couplers…Once the coupler issues are resolved ( improved- enhanced-verified) the track will come next…How would it work to take a couple decks of old playing cards and start shimming the track…This may be an easy way to gauge how much material would be required to correct the track problem…actually, if cut to proper width, and adding a few drops of glue, they could end up being a permanent fix…
BDT, your suggestion is really smart!!! I was thinking hard about how to create a transition grade but had no good answer. Your suggestions certainly will help! Thanks!
There’s no need to rip up the track. If it is not ballasted, you just need to loosen the track for about 2 feet, one foot each way from the start of the grade. Add shims under the flat to start of grade and keep checking your couplers. Use the longest equipment with the longest truck to coupler overhang. There will still be vertical movement of the couplers, but find the minimun amount of shim required to keep the cars coupled. For insurance add a bit more to the shim thickness for any couplers that may be slightly off. A 4% is a steep grade it usually needs a fairly long transition for the upeasing. You will need to check the top of the grade as well. The same thing can happen only the reverse without having an overeasing for the transition to the flat. Don’t consider the use of shelf couplers, some may recommend them, but any severe tranition can actually start to lift a truck and cause derailments. Good luck with it.
You could try useing a Kadee #118, it has knobs on the top and bottom to stop the coulplers from seperateing when going over grades, I’ve used them and they work very well on my walthers supperliners
there is always the posiblity that this grade is to steep to fast so the AMD-103 might just pull it off the tracks or rip the coupler off the botom of the car.
I use the 118 on the engine(back only) and all the cars
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