My first problem with KaDees . . .

You need to make much longer transitions from flat to grade, especial with such long cars.

Yes! Just watch the couplers as you roll the cars. If the ends of the cars dip suddenly, the couplers will release. I think the transition from flat to any incline, is the hardest part to get right. There should be some type of formula for the length of the transition vs. grade vs. length of cars.

 Basically, I would use the longest cars and make sure they arrive at the full grade without any dipping. I'm seeing just how difficult this is on my outdoor layout. There shouldn't be any noticeable curve to the start of the incline. It's the same problem at the top of the hill too!

 Try laying a couple of hundred feet of track outside without any bumps!

Well, nothing is cast in stone yet. It's not like I didn't wonder about what difficulties grades might cause me.

 

As is the norm, space is very limited! And I have my heart set on at least one long grade. It has to have corners too. So we shall see. The 2% seems to be wroking well. I do not have any plans to run trains underneath so I don't have to lift more than a couple of inches. I had planned on 4" but likely will scale that back to 3". I will experiment further before calling in the heavy construction equipment and blasting crews! :>J

You need a spiral easement in the vertical dimension

What this means is that you can't go directly from flat to a 4% grade and expect reliable operation with any kind of couplers.  You need to start with 1%, then 2%, etc., until you get to the 4%.

 

The easiest way to build grades is to use Woodland Scenics Foam grades for O gauge.  You can get them in everything from 1% to 4%.  The grade is precut.  All you have to do is lay it on a flat surface.  I have never had a problem with uncoupling using this product.

 

NH Joe

 

 

This is precisely the product I am using! But it did not occur to me to "ease" the grade by cutting and mixing the incline starters!

 

That will work.  

 

 

Well, I have similar problems on rough track.  It is worse with long passenger cars.  Invest in a Kadee height gauge - not sure they work on 3-rail track, but you can probably make it work.  Then get them all the same height.  Not trivial.  Then do as above - ease into things.

 

Otherwise, you will have to go back to couplers with more height.

Hi

 I had kadees couplers on all my coal cars at one time. We started setting up moguls

 found didn't work well with each mogul slightly deferent. was just enough for the cars to uncouple. Thy did look great. wound up putting stock ones back on.

 the stock ones are good for reliability. kept couple cars with kd for show.      

       
       
The height gauge works fine on 3-rail track. Just make sure you turn off the power.

I must confess, I don't know what "moguls" are but, as a member of the Independent Hi-Railears, MidWest Division, we had a VERY large modular layout, sometimes 90 feet by 75 feet. I was not the only member with all Kadee equipped rolling stock, and we rarely had any issues with the Kadee couplers coming uncoupled. In fact, the large "claws" tended to give others a LOT more trouble.

Jack, moguls are the bumps that are used in freestyle skiing. Also, it really isn't a fair comparison between the modular layout, with a ruling grade of 0%, and Terry's layout. My guess is, that every setup you guys did, you spent a fair amount of time leveling the legs over the uneven floors.

A 4% grade in a straight shot can cause uncoupling, especially if there is a dip or rough track where the cars may twist. The weight of the train runs the slack in and opens the knuckles. That's how the uncoupling action works, you create slack in the knuckles. If you see some back and froth jerking action in the train as it's on the down side of the grade, that's what causes the train to separate. This is usually worse on curved grades that straight track.

 

So you need to figure out why they are uncoupling.

 

A dip in the track at the bottom of the grade?

 

or just the weight of the train in a curve, a rough or twisting spot causing the couplers to swing open

There are a few things I'd add:

• If there's a reverse-curve somewhere in the grade. Body-mounted couplers take issue with that and you can get uncoupling.
• Excess tension in the load won't cause uncoupling, per se, but you can get a train separation when one car lifts up and/or the coupled car drops. This can be flexing in a coupler shank or where/how the box is mounted. I had this problem with Atlas 89-foot flats because their long-shank couplers were plastic and were flexing under load at the club. I replaced them with Kadee long-shank 700-series metal couplers and the problem was solved.
• Train weight distribution becomes an issue (as it is in the prototype). You don't want heavy cars at the rear of the train. Coming down grade, they'll increase "bucking" as the load shifts. You want the heavy cars up front. What's ironic is that the heavy cars are usually the longer ones which would normally need to be toward the rear on sharper curves so you have more flanges up front to prevent string-lining.
• Short cars coupled to long cars. This often results in derailment on sharp curves but can also cause uncoupling because the coupler angle gets strange. Being on a grade amplifies the problem. Made this mistake early on and of course the mishap occurred in a tunnel.

Despite the occasional quirk, I'm slowly switching my fleet over to Kadees and have no regrets.