Couplers, body or truck mount, why, why not?

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new guy

Active Member
Not being worried about the prototypical look or looks in general when it comes to smooth running, WHAT are the pros and cons of truck vs body mounted couplers and their various lengths among the more experienced 'layout runners' who may see this thread?

Thank you for any advice and or examples of 'layout world' experiences concerning this issue.

Happy Rolling!
 

montanan

Whiskey Merchant
My choice is body mounted couplers, hands down. I enjoy switching and end up pushing cars with a switcher a lot. The chances of derailing in this case is a lot more with truck mounted couplers. It is also easier to have the couplers (Kadee) adjusted to the proper height with body mounted couplers.

I rarely if ever have problems with couplers, but recently when I picked up some passenger cars from Garry, the mix of couplers, body mounted and truck mounted was a mess. All of my passenger cars have body mounted couplers. Some of the cars I got from Garry had truck mounted couplers. I ended up having derailments with this combination. My radius are broad, with a minimum of 32 inches and I never had derailment problems before. These additions will soon have the truck mounted couplers removed and will have body mounted couplers installed.
 

Iron Horseman

Well-Known Member
With truck mounted couplers the coupler follows the center line of the track. It allows cars of different lengths to couple easy. It allows coupling on curves to be easy. They eliminates the "S" curve issue. On the con side they require modification of the loco and rolling stock bodies to allow the coupler to move (those nasty looking gashes in the front of F, E, PA, and FA pilots). They mostly eliminate the possibility of footboards and other front / rear end detail around the couplers. Operationally since the stress of the train comes down from the body through the bolster to the truck then through the truck to the coupler they are continually in a "bind" state while the train is running. On a curve that "bind" also applies side to side. The longer the train the greater this bind factor is. For most normal size model railroads it is irrelevant. Truck mounted couplers is one reason Lionel O-gauge can go around such tight corners. Finally uncoupling truck mounted couplers has a greater chance of derailing the car since any accidental side or down stress is going directly to the wheels. I successfully use truck mounted couplers on n-scale and g-gauge (Fn3). I think this is because the N-scale cars are so light the stress of the bind is minimized. On the g-gauge, the trains are so short and the cars so massive the down force overcomes the bind factor. I am certain if I tried to run longer 40-80 car trains it could be a totally different story.

Body mounted couplers pull the trains bodies directly. The only bind factor is that caused by the truck itself. The counter to that is the lateral stress in a curve. Cars with body mounted couplers are more likely to string line in a heavy or hard to move train. Once again for most normal size model railroads this is not a big issue. Body mounted couplers look better because one can add all the detail that normally is on the end of a car or loco surrounding the coupler pocket. Body mounted couplers and curves don't like each other because the couplers swing out toward the outside rail. Cars of different lengths have different swing distances, so can have a hard time coupling together and if coupled can derail one another. S-curves are a bane because the couplers on each side of the "S" are headed toward the opposite rail. The tighter the curves the more pronounced the problem. Body mounted couplers is one reason equipment using them needs larger radius curves. I use body mounted couplers on my HO equipment.

And yes, mixing the two types is the worst. It introduces the bad aspects of both without the benefits of either.
 

new guy

Active Member
WOW! Thanks for the insights! Most everything I have is truck mounted so I'll lean that way when installing new gear to the 'old' stock I'm getting from the dealer guy and not worry about changing everything I already have! Some stuff has the trucks mounted too far back to go with the truck mount but they are 'specials' and will keep to themselves, the Riv logging cars are a good example.
WIN_20151106_120157.JPGPlus the riv's already have metal wheels! (at 60 bucks for a pair they BETTER!) The covered hopper on the left (I got it for a buck!, It opens and there were removable 'hay bales' or something in there!) has old Tyco looking couplers and well worn plastic wheels that will all be swapped out. I'll be running a broad mix of eras and whatnot on my lines so I'll try to keep everybody on the 'same page' with couplers. Kaydee 'longs' is my weapon of choice!

Thanks again and stand by for queries about trucks!
 

RBMNfan

Member
In general body mount are better. All my cars have body mounted couplers. Having made a general sweeping statement I will get to the exceptions. I have a branch line with sharp (13-14") radius. My 36' hoppers work reliability over this trackage. My 40' boxcars on the other hand sometimes have multiple derailments. I now looking for older 36" boxcars to run over the branch. I also bought two nice 72'? Passenger cars. They have body mounted couplers. I test ran them behind my 4-4-0 and found consistent derailments at the same locations. I suddenly realized the beginning of the 18" radius staging tracks were the problem area. The 24" radius visible portion of the layout wasn't an issue. I ended up sticking a boxcar between the locomotive and passenger cars. Now the train doesn't derail because I have a short car, (tender) coupled with a medium length car, ( boxcar) coupled with a long car (passenger car). Truck mounted couplers eliminate the thinking and engineering from the situation. For short trains they are ok, for a longer train they can contribute to issues.

Sent from my XT1080 using Tapatalk
 

k4kfh

Member
I like body mounted couplers better as long as they're metal. It seems when going up/down grades with body-mounted plastic couplers, I run into more problems than with truck mounted ones.

I'll never buy another plastic coupler again now that I've been bitten by the "virtually indestructible metal couplers" bug.
 

dinwitty

Member
Truck mounted couplers put more stress on the trucks, and that shows up madly when you back up on curves or even straights. Derail city.
 

montanan

Whiskey Merchant
Body mounted couplers also don't wirk well with truck mounted couplers. I had some time to work on the layout yeaterday and I put my "tourist" train made up of Riverossi and AHM passenger cars on the rails.

The train couldn't complete one lap around the layout without having a derailment of some sort. Due to their length, passenger cars will probably be more prone to problems than freight equipment, but many newer generation freight cars are also pretty long.

IMAG0548.jpg These are the Riverossi cars. This photo shows how far off center the coupler is when the car would be going through a curve. This offset tends to force one of the two cars off the track. The long coupler also can have a problem with coupler height. I purposely built in many grades. Some as steep as two and a half percent to as little as a half of a percent. I was very careful with these grades making sure that I had a good transition both on grades and curves. Watching the cars very carefully with the truck mounted couplers, it was easy to see that the coupler height did change somewhat as they passed from a grade to a level section of track.

I am extremely happy with my track work and after being in place for over 25 years I am having no problems with it. A couple of years ago, I had a 40 or so car train running when my wife called me up for some reason or another and I never went back in the train room until the next day. The train was still logging laps with no problems at all.

After pulling all of the Riverossi cars off the tracks, I put an eight car train of the Walthers North Coast Limited on the tracks (the train on the right) and let it run laps around the layout.

IMAG0506-1.jpg

Ran it for around an hour while I was doing other things on the layour and not a single derailment.

The Riverossi cars are now on the workbench waiting to have the truck mounted couplers removed and body mounted couplers installed.
 
Body mounted couplers also don't wirk well with truck mounted couplers. I had some time to work on the layout yeaterday and I put my "tourist" train made up of Riverossi and AHM passenger cars on the rails.

The train couldn't complete one lap around the layout without having a derailment of some sort. Due to their length, passenger cars will probably be more prone to problems than freight equipment, but many newer generation freight cars are also pretty long.

View attachment 53861 These are the Riverossi cars. This photo shows how far off center the coupler is when the car would be going through a curve. This offset tends to force one of the two cars off the track. The long coupler also can have a problem with coupler height. I purposely built in many grades. Some as steep as two and a half percent to as little as a half of a percent. I was very careful with these grades making sure that I had a good transition both on grades and curves. Watching the cars very carefully with the truck mounted couplers, it was easy to see that the coupler height did change somewhat as they passed from a grade to a level section of track.

I am extremely happy with my track work and after being in place for over 25 years I am having no problems with it. A couple of years ago, I had a 40 or so car train running when my wife called me up for some reason or another and I never went back in the train room until the next day. The train was still logging laps with no problems at all.

After pulling all of the Riverossi cars off the tracks, I put an eight car train of the Walthers North Coast Limited on the tracks (the train on the right) and let it run laps around the layout.

View attachment 53862

Ran it for around an hour while I was doing other things on the layour and not a single derailment.

The Riverossi cars are now on the workbench waiting to have the truck mounted couplers removed and body mounted couplers installed.
I have a ton of old Rivarossi passenger cars with their original truck-mounted couplers... horn-hooks, even! Pretty much everything else on my layout is body-mounted kadee couplers. But I've never felt much urge to go to the trouble of changing the Riv's. They tend to run as units all by themselves, not intermixed with other stuff, and they're just as track-worthy and reliable as anything else I've got... In fact, they're more 'solid' than a very expensive MTH passenger set I've got... In part, it may help that they are 6-wheel trucks, giving a bit more lateral 'bite' on the track versus freight-style 4-wheel trucks. Really no experience with truck-mount couplers on those to share.

Mind you... that's unless you 'push' them around a tight-ish curve or up any kind of grade. Then it's definitely derail-city. I'm not sure if that's more the fault of the truck-mounting or the horn-hooks. Both are notorious for derailing when pushing under any stress. But I basically never have reason to push them around a curve or uphill, so they work fine for me.

In general, while truck-mounted couplers are seen as 'old school' and body mounted is 'better'... They do as others have pointed out give the advantage of going around tighter curves. I can take my Riv passenger cars up my branchline with 28" radius where no other full-length passenger car with body-mounted couplers could possibly go. Since many out there suffer with tight curves due to space constraints it is something to consider...
 

montanan

Whiskey Merchant
The problem I have is that of all of the equipment I have are equipped with body mounted couplers. I can put a train together in any type of consist. A string of freight cars with a couple of passenger cars in the train or passenger cars of different lengths like in this video. (1080 p) The first car is a Con Cor 72 foot car and the second is a very old MDC heavyweight car equipped with Central Valley Trucks. I also have a couple of old Athearn Harriman cars and I can put any cars anywhere in the train and have no derailment problems at all. All of my curves are pretty broad so it's not like I am trying to force them through a tight radius.

[video=youtube;Y7zO8kdjGGA]https://www.youtube.com/watch?v=Y7zO8kdjGGA[/video]

Being that half of the Northern Pacific cars with the pine tree paint scheme are body mounted and the rest truck mounted, they don't like running together at all and will have to be modified if I want to run them in one train. These are the only cars I own with truck mounted couplers. It is a relatively quick fix.
 
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