Body mount couplers, what's the big deal?

[Scottl]

I have been hanging around RW for a while and there is frequent reference and effort devoted to the notion and intricacies of body mounted couplers.  Like many things here, I assumed the rationale for this would become obvious with time, but the post about the NZT couplers-to-be and finally spending some time running trains has left me wondering:  what's the big deal?  If it ain't broke, why fix it?

To give some context, I have not actually run n-scale trains very much.  Usually, I am in the process of some project that prevents me from actually running trains, so my operational experience is limited.  In the past few weeks, I've been running 17-19 car trains with a pair of locos up and down 2% grades, through curves of about 12-18" radius, and I've had no problem with my motley assortment of cars, all with truck mounted couplers.  Some have randomly decoupled on grades, but I don't think that has anything to do with the mounting of the coupler.

There are some great threads here about how to body mount, along with some ingenious solutions:

http://therailwire.net/forum/index.php?topic=21980.0

But I have come up with very few substantial reasons why people would be so concerned about this particular aspect.  I can see how when coupling on curves body mount couplers might actually make life more difficult.  Certainly, going through a collection of rolling stock and going to the trouble and cost of doing so is another aspect.  I am not convinced it adds realism either, in some cases people are cutting into the body shell to make it all work.  Having said that, I am a big fan of the Fox Valley and BLMA metal wheels and I see the benefits of lowering the ride height of many stock cars.

I can imagine on very long trains the forces associated with grades or curves could create some issues, although I won't pretend to know the physics of this.  I have a modest sized layout and have not had issues, but this coupler fixation seems to be common whether a person has a basement  or a HCD layout.

So, what gives?  Is this some kind of n-scale make work project, or something I need to deal with (eventually)?

[avel]

More prototypical.

When backing, say 20 cars, into a yard through turnouts you are less likely to derail. Even more of an issue with the finer flanges on wheels that are offered these days.

[havingfuntoo]

Next time you have your 17 to 19 car train rolling around the track ....... try going back wards ........ better still try pushing the train through two sets of switches, like you would have in a yard ladder set up ........ it will become clearly abundant to you what people are going on about. If the NZT couplers help to overcome some of these problem I for one will not only be very thankful for the effort put into developing them but also very supportive by replacing the hundreds of mixtures I have on my collection of equipment. It is not a matter of if it is not broken why fix it .... it is all about making the model perform more like the real thing..... but there again every one does their own thing in model trains ..... no one is right ...... no one is wrong ...... just as long as you the individual enjoys what you are doing. Have fun with model trains ..... don't be judgmental. 

[GaryHinshaw]

It's an excellent question Scott.  A few years ago, when I was first getting back in to N, I was determined to adopt MT truck-mounted couplers as my uniform standard (with FVM wheels when they came along).  I still think this is a good simple solution that should work just fine for most.  I don't disagree that pushing a cut of these cars through a yard ladder is problematic, but I wasn't affected by this.

The body-mount tipping point for me was the BLMA trucks for three reasons:  1. they came in a 100T version, which MT does not offer, but which look much better (to me) under modern cars; 2. the lower cross-member made lowering ride height much simpler; and 3. the wheels were very nice (though I still like the FVM wheels just as much).  If I were to adopt them as a new standard I had to convert to body mounts, hence the thread I started.

If MT made a 100T truck with coupler, or if anyone made a 100T truck with a good coupler, I'd be tempted to just stick with that because body-mounting is a pain, and not without performance issues of its own; and I still don't have a solution that I'm very happy with.  I hope NZT changes that.   

-Gary

[Brakie]

More prototypical.

When backing, say 20 cars, into a yard through turnouts you are less likely to derail. Even more of an issue with the finer flanges on wheels that are offered these days.

I have backed 27 cars through a yard ladder at the club while making up trains and had zero problems at scale switching speeds.

I fully believe 90% of derailments is caused by poor track work and excessive speed while backing through switches.

A thing to remember is the side to side play in the coupler will help guide the trucks through switches at slow switching speeds.

[Ian MacMillan]

For me its ride height and closer prototypical coupling. And like others have pointed out, backing a set of cars is less prone to pushing the truck off center, and eventually over the railhead.

[milw156]

Ya ever see truck mounted trucks on the prototype??? there is a reason for that!  Side benefit to body mounting, once had a coupler pin fall out while train was in motion on an N Trak laouyout. It ran for about a half hour without anyone knowing about the problem. Wasn't till I was taking it off the track to put it away that I found out about it. Since the pulling force was going thru the frames rather than trucks, it did not cause a problem.
Rick

[mark.hinds]

I have backed 27 cars through a yard ladder at the club while making up trains and had zero problems at scale switching speeds.

I fully believe 90% of derailments is caused by poor track work and excessive speed while backing through switches.

A thing to remember is the side to side play in the coupler will help guide the trucks through switches at slow switching speeds.

The above observations are quite likely to be true.  I could back a 15-20 (truck-mounted) car train at full speed (50 mph) through my yard ladders with no problems.  Track was carefully-laid code 70 Shinohara, which I currently plan to replace; maybe code 55 Atlas will be less forgiving. 

MH

[SAH]

I felt the same way until I started participating in operating sessions.  We're lucky to have 6 large N scale layouts here in central North Carolina that have regular ops sessions.  All use code 55 rail.  My observation is that as the % of body mounted couplers and weighted cars increase the number of derailments decrease.  And when there is a derailment a car with truck mounted couplers is nearly always involved.  The HO guys have known this for years.  The N scale community is finally catching on and it probably has to do with the number of N scale layouts that have made it to the operations stage now.

Of course everyone is free to do as they choose.  I'm sold on body mounted couplers.

Steve

[Scottl]

Thanks everyone for the responses.  It would seem that the primary benefit is associated with backing up, although like some, I have not had any problems with this maneuver.  It is interesting that the BLMA trucks, which are very realistic in my view, essentially force the issue.  As Gary points out, if the BLMA trucks had mounted couplers, it might be another story...

There seem to be a number of related issues:  car weighting, track work, and operations.  I have no doubts that cars that are weighted appropriately are more reliable and track better, and I suspect this is (usually) the easiest factor to deal with.  Some cars don't have simple locations to add weight, but most do.

Track work is definitely a big issue.  I have problems with some turnouts in terms of derailments, picking points, etc, but I'll have to look at it very carefully to see if the couplers are playing a role. 

 

[davefoxx]

what's the big deal?  If it ain't broke, why fix it?

The previous responses to this thread have already hit the main points that I wanted to state.  Therefore, instead of unnecessarily repeating that good information, I'll just add that it IS "broke" to many of us that seek more prototypical look and operation, so that's why we choose to fix it.  If truck mounts work for you, leave them alone and enjoy!

DFF

[peteski]

Main reason is realism - most 1:1 trains have coupler pockets fastened directly to the under frame.

All the other excuses are pretty much given by the body-mounted coupler enthusiasts trying to sway others to convert.  IMO, on an average size layout with decent trackwork, the body mounting does not make much difference while backing up trains - even those trains which are considered long for that average-size layouts.  As far as forward travel goes, body mounting doesn't make a difference at all. We run 100 car trains on N-Trak layouts with truck mounted couplers without much of a problem.  And N-Trak trackwork is terrible. Well, not the trackwork per se, but the joints between modules are quite nasty (uneven, and large gaps in the rail).

For those average size layouts with 15" or less radius curves actually makes sense to keep truck-mounted couplers on passenger cars (or other long cars).

[Scottl]

Fair enough, but I think the argument that it looks more prototypical is overstated.   I started with the assumption that was the reason, but found few examples where the coupler mounting improved the look.  The truck, wheels and ride height definitely improve the look to my eye, but the body mount coupler seems almost incidental towards that effort. 

I guess I raised it because there is a lot of chatter on RW about body mounts, pleas for manufacturers to build them in, creating new underbodies for venerable body styles like the MT PS1, etc., but I could not find a reference to the benefits. 

I'm not arguing for one way or the other, but it was an honest question. 

[Brakie]

Main reason is realism - most 1:1 trains have coupler pockets fastened directly to the under frame.
------------------------
Food for thought.

The prototype has large sweeping curves whereas the the majority of the model layouts may not have.

One concern I've seen is body mount couplers on long 87'  cars in HO even with 36" curves there was some derailments.

Here is my personal thoughts on those derailments.

It is my opinion that the coupler box was a tad off center on those cars that derail since the other 86' auto parts cars that had body mounted couplers did not derail..

So,the lesson here is to ensure the coupler box is centered on these long cars..

[peteski]

I guess I raised it because there is a lot of chatter on RW about body mounts, pleas for manufacturers to build them in, creating new underbodies for venerable body styles like the MT PS1, etc., but I could not find a reference to the benefits. 

Because I don't believe that there is a solid reference showing benefits which are important enough to warrant someone to convert all their models to body mounted couplers. There are hundreds of N scale layouts out there operating (for many decades)  using truck mounted couplers without any problems.

Brakie:  Even perfectly centered body-mounted couplers on long cars which have long overhangs will not be happy on average layout's curves (especially without easements).