Coupling Passenger Cars

[GN goat kid]

I'm trying to figure out the couplers to use on 80' (HO scale) passenger cars with diaphrams. I understand about using easements, supper elevation, and widest possible curves, but still, it seems to me, I think there must be a way to connect passenger cars that minimizes the car end offset in curves. Any help or thoughts would be greatly appreciated.

Thanks,

The GN goat kid

[Mark R.]

Unfortunately, it's geometrically impossible given the radii we are forced to use within our confines.

I once had what I thought might be the answer ....

I mounted two trucks on a span bolster. The bolster was long enough to correctly position each truck correctly under the end of two adjacent cars. I then made a pin mount right in the middle of the bolster with tabs on the end of each car to mount on that common pin.

The end result worked perfectly as far as keeping the diaphragms together through any curve or turnout. The downside was that the trucks were now independent of the body and would swing outwards beyond the body itself in curves. That looked much worse than the diaphragms se-sawing against each other !

I had thought to find a happy medium would be to still use the span bolster, only instead of a common pin mount, mount the cars to the span about an inch apart. Might split the difference between the two situations, but I never actually went any further with the project ....

Mark.  

[NHTX]

    GN Goat kid,

    Simply put, passenger car end offset on curves is a product of car length, curve radii and truck center spacing.  With 80-85 foot cars the only negotiable is curve radii--the larger the curve, the closer car ends will stay toward the track centerline.  Moving the truck pivots closer to the end sills should also cause less end swing but steps prevent this in most cases.  Shorter cars may be the only sure cure if the curves are at maximum radius.

[RR_Mel]

I have Athearn 72’ Heavy Weight and Streamline passenger cars and they work OK on 24” radius curves.  I’m using Kadee #119 Scale Shelf Couplers on all of my Athearn Passenger cars, all Talgo truck mounted couplers.  The only diaphragms I’ve been able to get to work on a 24”radius are the Walthers 933-429.

 

I started out with 85’ passenger cars and they don’t look very good on 24” radius and will not handle 18” radius turnouts (#4) without derailing.  The 72’ cars are the longest cars I have now.

 

 

 

Mel

 

 

My Model Railroad   

http://melvineperry.blogspot.com/

 

Bakersfield, California

 

I'm beginning to realize that aging is not for wimps.

 

[mbinsewi]

RR_Mel

The only diaphragms I’ve been able to get to work on a 24”radius are the Walthers 933-429.

Thanks Mel.  I'm putting together a train using the Athearn 72' cars, and an F7A and B set, both powered, both Athearn.

I'll have to check those out. I'm using the streamline cars.

Mike.

[RR_Mel]

mbinsewi

 

Thanks Mel.  I'm putting together a train using the Athearn 72' cars, and an F7A and B set, both powered, both Athearn.

I'll have to check those out. I'm using the streamline cars.

Mike.

 

I fought diaphragm problems for several years and the Walthers work better than any other diaphragm I tried.  Diaphragms cause all kinds of problems, uncoupling and derailing being the worse.  The Shelf Couplers really help.

 

 

 

 

That is on a 18” radius, you can see the potential problems.

 

 

 

Mel

 

 

My Model Railroad   

http://melvineperry.blogspot.com/

 

Bakersfield, California

 

I'm beginning to realize that aging is not for wimps.

 

[Mark R.]

My smallest radius is 24 inch, so those Walthers diaphragms would work fine for me. My real annoyance is the side to side mis-alignment when transitioning a crossover or even just entering a passing track where there is even slight "s" involved.

Mark.

[NHTX]

   I have seen some people with sharper curves and crossovers use a single diaphragm between two cars.  Fewer derailments due to striker "coupling".

[RR_Mel]

The Walthers 933-429 have a smooth plate and slip and slide nicely.  After assembly any rough edges must be sanded smooth, the slip and slide is a must for any S type curve or even a 24” radius.

 

I would like to park some cars in my yard but due to space limitations I had to use #4 turnouts and they are a NO NO for diaphragms.  I have used a switcher to individually park and unpark passenger cars in my yard but that’s not my thing.

 

The sharpest radius on my mainline is 24” and they all clear it but it’s marginal.  The 24” was originally 30” but do to a huge Mel design error I had to rebuild the curve and 24” was the best I could do under the circumstances.  Never install a turnout at a grade transition!!!!  That was a major undertaking to correct some 15 years later.

 

I used a Bowser Big Boy, Rivarossi Cab Forward and Athearn PAs to check my original track work and they cleared the turnout easily, down the road I bought some Proto 2000 E7s and they would not go through the diversion without derailing.  I swapped out the original Atlas #6 turnout with a Peco and a Shinohara then back to a new Atlas nothing worked.  Every other locomotive would clear all of the turnouts, Proto SD9s would but not the E7s.  After moving the turnout the E7s worked great.

 

 

Mel

 

 

My Model Railroad   

http://melvineperry.blogspot.com/

 

Bakersfield, California

 

I'm beginning to realize that aging is not for wimps.

 

[nealknows]

If you're more concerned about the cars running versus appearance on tight radius, I added a long shank Kadee coupler #146 (or #46) to one end of the car and a standard Kadee to the other. If need be, put the long shank on both ends. I have a couple Walthers cars that I added the long shank to both ends. They run fine on the railroad where I have 24" radius. They look okay with the diaphragms and long shank couplers. The cars without the diaphragm, well, it is what it is....

Neal

[ATLANTIC CENTRAL]

Kadee has this relatively new item:

https://www.kadee.com/htmbord/page451.htm

I have not tried these yet, but most of my passenger cars are equipped with these:

https://www.kadee.com/htmbord/page36.htm

These have a longer shank, and a box that lets them swing wide, and I set them back farther on the car floor to still get close coupling and touching diaphragms.

I use American Limited diaphragms and all my cars run fine down to about 28" radius with diaphragms touching all the time.

Most of my cars are Athearn and ConCor 72' cars, but even the few 80' cars I have work fine.

Even though I have tested these down to about 28" radius, here is my disclaimer - my actual minimum radius on the old layout was 36" with easements, the new layout will have the same 36" minimum.

In this photo you can see the close coupling.

Sheldon 

[GN goat kid]

Mark,

Thanks for your thoughts. Could you post a diagram of the underside of two cars with your proposed, untested solution. I'd like to give it a try.

-GN goat kid

[GN goat kid]

Hi Mel,

Thanks for you thoughts and experience. Could you, please, add a photo of the underside of the two Daylights you show? Are these are the ones with the shelf couplers?

-GN goat kid

[RR_Mel]

GN goat kid

Hi Mel,

Thanks for you thoughts and experience. Could you, please, add a photo of the underside of the two Daylights you show? Are these are the ones with the shelf couplers?

-GN goat kid

 

These Athearn trucks have Kadee Scale Shelf Couplers.

 

 

They fit my Athearn Daylight passenger cars. 

 

 

The pictures were taken in 2016 when I was overhauling my Daylight lighting.  The power pickup is not for the lighting, I have a DCC decoder (Digitrax FL1) in the observation car to control the backup light.

 

 

 

 

The relay controls the backup light with F4.

 

 

Mel

 

 

My Model Railroad   

http://melvineperry.blogspot.com/

 

Bakersfield, California

 

I'm beginning to realize that aging is not for wimps.

 

[GN goat kid]

Thanks Mel,

This is really very great, and inspiring. I like the backup light decoder.

-Michael, the GN goat kid.

[robert sylvester]

I have agree with Mel. I have tried all types of diaphragms but they don't always operate well on lesser curves.

So several years ago I stopped buying all of the plastic diaphragms that you had to piece together, to may parts, and when gluing them together they would inevadably get stuck and the parts would not work right so I trashed them and went back to the old Walthers bellows fibre diaphragms with the plastic striker plate, cut one section out to shorten them and they work just fine on my 28 inch curves.Then I found these:

Made by Precision Scale. They are made of a very thin soft rubber in the bellows form with a brass stricker plate. Again, I remove one section of the bellows to shorten the length of the diaphragm, using contact cement I apply them to the coach then line up the stricker plate and apply that to the rubber diaphragm. Let it all dry and I have good contact and they don't derail on my 28 inch curves.

In my opinion they are much easier to apply than the other diaphragms and to my eyes they look just fine.

Thanks,

Robert Sylvester

Newberry-Columbia, SC

[Canalligators]

I also use the Walthers fiber diaphragms, successfully. I have minimum 21" curves and the diaphragms would catch on each other on sharp turns. So I glued a piece of very thin clear plastic over the opening to prevent the catching. Since this was on a dedicated trainset and I could always run the cars the same way forward, I only had to put a clear cover on one of the sides. The plastic I used was transparency film, don't know if you can easily find something like that anymore.

[wojosa31]

RR_Mel

That is on a 18” radius, you can see the potential problems.

The 18" radius curve photo does show the diaphragms working as intended, just like on the prototype. I have had mixed success with Walthers fabric diaphragms, as well as fixed plastic varietys. My minimum radius is 30".

As far as the diaphragms cross action while transversing the "S" curve on crossovers, the Original Metroliner MU Cars had a similar problem, negotiating the relatively tight crossovers at either end of Penn Station, Baltimore, as well as along certain routes in Penn Station, New York. Train crews had to close off car to car access at these locations due to the sharply reduced clearance in the crossover.

Boris

[RR_Mel]

I thought about using transparency film but tried sanding a bevel edge on the inside of the diaphragms to prevent them catching each other and it worked.  I did a rough cut using a mini file to get them to about a 45° angle then 240 grit sandpaper on the entire plate.  I had beveled the outside edge to 45° during installation.  The trick seems to be getting the total surface smooth as possible to promote the slip and slide motion of the plates.

 

I haven’t had any derailing since I smoothed all the plates.  As for uncoupling goes the Kadee Scale Shelf Couplers have never accidently become uncoupled.

 

A warning about using shelf couplers, they do not uncouple on their own!  Should you have a truck derail for some reason the shelf couplers will not release continuing to pull a bouncing car or cars and that can be very dangerous.  I have added weight to all my locomotives and they have super drawbar so when a coupler doesn’t release after an accidental derail instant breaking is the only way to stop all kinds of damage.

 

My track work is very close to perfect but my aging brain isn’t and derails do to happen, operator error.  Ever had to replace an Athearn truck because the couplers didn’t release after picking a turnout, very embarrassing.  I have a pair of E7s with a total of 11oz. of drawbar, need I say more.

 

 

Mel

 

 

My Model Railroad   

http://melvineperry.blogspot.com/

 

Bakersfield, California

 

I'm beginning to realize that aging is not for wimps.

 

[BroadwayLion]

There is the function of the distance of the truck center to the end of the car.

Old NYCT (BMT) subway cars used a common truck between the cars to allow safe passabe between the cars.

Nowadays they just lock the storm doors, but better days are coming!

Anyway, if you move the trucks closer to the end of the car, you minimise the overswing, BUT... you increase the belly overhang. you may take out some of your wayside with the middle of the car which now requires more space.

NYCT built some special "finger cars" to test the tunnels and the wayside before odering 75' cars. They had to shave the wayside back in many places, relocate signals and other equipment etc to allow the longer cars to pass. The order had to carefully specifiy whre the king pins had to be.

They have since gone back to 60' cars and will not repeat an order for 75's.

LION runs the shorter IRT type cars which are 50' long and look supurb on da layout of him.

 

ROAR

[mbinsewi]

I just checked out the Precision Scale diaphragms, over $11, for a pkg of 2.

I'll go with Walthers, as Mel has seem to prove to me they will work.  My radius is 24".

Mike.

[Canalligators]

RR_Mel

...A warning about using shelf couplers, they do not uncouple on their own!...

They're also difficult to uncouple manually, but on the balance I'll keep them.

[robert sylvester]

Yes, the Precision Scale diaphragms sell for $10-11 for a package of two but what you may not know is that there are four striker plates, because you don't use the entire piece of the diaphragm you cut them in two, therefor each package is for two passenger cars not one, it would be to long and probably bind up the car.

I will send pictures later today and explain in better detail. So the cost is actually a little more than $2 per diaphragm, and that is not too bad.

Robert Sylvester

Newberry-Columbia Line

[mbinsewi]

robert sylvester

therefor each package is for two passenger cars not one, it would be to long and probably bind up the car.

OK, I didn't notice that, thanks for the clarification.

Mike.