Best Of What wheels on which car?

[lock4244]

Sort of related to the recent subject of couplers and trucks, I was wondering if there is a resource out there for determining what size on wheels go with which car? Specifically, I'm interested in which wheels 28", 33", or 36" would be correct for an RC bi-level autorack (my assumption is 28") or a Bluford 86' autoparts boxcar (or the Train-worx version)? Is there any surefired way to determine this for all cars (besides checking the prototype)?

[wcfn100]

There are only two RTR models for 28" wheels, the Vert-a-pak and some Automax carriers.  None of the RC or MT autoracks or flats take 28" wheels.


For the 36" wheel - this is a copied Robbman post from TB

RobbmanNovember 9th, 2007, 05:58 PM
The AAR has rasied axle limits over the years... without getting overly technical (if you really want that, read my post here :Train weight on bridges (http://www.trainorders.com/discussion/read.php?2,1465530))

From Jan 1st 1994 to current, 36" wheels would be used on any car thats 286K GRL

From Jan 1st 1963, to Dec 31st 1993, 263K was the max GRL for 4 36" wheels...

Before Dec 31st 1962, 251K was the max...

Note that 36" wheels basically dictate the use of 6.5 x 12" axles... but I digress

GRL is Gross Rail Load... like B&O says... add up the light weight and load limit and use that... just make note of your era.

Jason

[lock4244]

Really? The racks and flats take 36" wheels?

[Packer]

I think the protoypes do have 28", but from what I gather about microtrains they are kind of toyish.

My general rule of thumb since I model 1975-1985 is 36s for most hoppers (FMC covered, 100 ton open, etc) 33s for everything else. 28s go for autoracks.

I'll ask this now, what is the prototype wheelsize for 85' fluch deck TOFC flats?

[lock4244]

I've a ton of RC racks and I want to put some metal wheels on them. I assumed that the prototype cars had little (28") wheels on them. For the record, the era is 1987-89.

[Mark5]

I believe 33" is what you are looking for

http://www.trainboard.com/grapevine/showthread.php?t=107374

[lock4244]

I believe 33" is what you are looking for

http://www.trainboard.com/grapevine/showthread.php?t=107374

Thanks... I'll go with 33" on the RC bi-levels.

I noticed on an Atlas percision design rib boxcar (Southern if it matters) that the wheels on this car look smaller than the 36" FVM wheels and other Accumate wheels. Would it be correct to assume that these are supposed to be 33" as well?

[wcfn100]

Really? The racks and flats take 36" wheels?

No.

I think the protoypes do have 28", but from what I gather about microtrains they are kind of toyish.

I'll ask this now, what is the prototype wheelsize for 85' fluch deck TOFC flats?

The only TOFC flats that had 28" wheels were the Lo-Deck cars.  Lo-Deck cars cars were used for trailers and with autoracks installed, but have not been made in N scale RTR.

So unless the 85' flat you are modeling is a Lo-deck car, it would take 33" wheels.

Jason

[Mark5]

Is there a place on tri-level enclosed racks that indicates wheel diameter?

A nice close up of certain cars might help people sort this out as it seems to be a recurring controversy (28" or 33")

[wcfn100]

Is there a place on tri-level enclosed racks that indicates wheel diameter?

Yes, but that only helps if the model is actually that prototype.


Jason

[Mark5]

Is there a place on tri-level enclosed racks that indicates wheel diameter?

Yes, but that only helps if the model is actually that prototype.


Jason

Yes, but proto information is the info that matters here. The next question is which proto is the model.

My understanding (proto) is:

• Bi-level Enclosed - 33"
• Tri-level Enclosed - some 28" some 33" - how do we sort this out?
• I assume open bi-level racks are 33"
• What about open tri-level racks? - 33"?

As for models, if we ignore the Concor model, then we only have two enclosed prototypes to deal with (RC and MT).

For the RC bi-enclosed rack, it's safe to say it's proto rides 33" wheels (right?)

For the MT tri-enclosed rack, what did its proto ride on?

Mark

[wcfn100]

Yes, but proto information is the info that matters here. The next question is which proto is the model.

My understanding (proto) is:

• Bi-level Enclosed - 33"
• Tri-level Enclosed - some 28" some 33" - how do we sort this out?
• I assume open bi-level racks are 33"
• What about open tri-level racks? - 33"?

As for models, if we ignore the Concor model, then we only have two enclosed prototypes to deal with (RC and MT).

For the RC bi-enclosed rack, it's safe to say it's proto rides 33" wheels (right?)

For the MT tri-enclosed rack, what did its proto ride on?

Mark

OK, here's the thing.  You can't really go by the rack to determine wheel size, at least not for 60's-70's era stuff.  In the modern day it may be simpler.  The wheel size is determined by the flat.  So to answer the question about open rack car, you have to look at the flat, it's the only way unless maybe you can become an expert on the various racks and know that there were some in particular that would only have been put on a low-deck car.  There were also low-deck trailer flats that used 28" wheels.

But all that's really important is what to put on the currently available models.

About the only MTL model in this fight that has had prototype pinned down is the 89' flatcar.  It's a late-60's/early 70's ACF or PS flush high deck (or high level) car which would have 33" wheels without question.  AFAIK, the open rack cars are the same flat with a rack put on so the wheels are still 33".  These cars are plausible and I think you could come up with a picture of a tri-level rack on that type of flat from that era.  The problem is the closed rack car. Is there even a prototype? 

Here's what I've surmised from all that I've read, proto and MTL descriptions.

In the 70's, most of the tri-level cars got shopped to get a fully enclosed racks.  At the same time, many (most, all?) of the high deck car were removed (if not previously) from tri-level service and put into general trailer service or maybe bi-level service in favor of low-deck cars.  I think the MTL car is supposed to represent these cars that got shopped with new racks, but in typical MTL fashion, no regard was given to reality.  I think the flat used under the tri-level is basically the same flat as they used previously in which case, the car would still have 33" wheels even if all the proto paint schemes they use had 28" wheels.  Regardless of what I think, there is nothing about the MTL enclosed flat to even suggest it's a low level car.

Some may decide to go by the proto scheme to determine wheel size, which is fine but will make the car look even more ridiculous.  But if you do, your following the lead of a company who painted these tri-level cars into this scheme:




Those have the reporting marks 'TTGX' which I believe by definition, are bi-level cars.  So follow away...



Jason

[Mark5]

I 100% understand that the flats and not the racks determine the wheel size. On the model side it sounds like the MT ETTX may have no prototype. ;D

I'm looking for proto examples of 33" tr-level enclosed auto racks. Generally, the low slung 28" flats are easy to ID due to the "cut outs" around the trucks. But ... does this mean that all the non "cut-out" flats are 33" wheelsets?

ETTX pix:
28" Wheelset:
http://crcyc.railfan.net/crrs/auto/ettx701252.jpg

Non "cut-out" ETTX listed as 28" wheels:
http://www.trainweb.org/nwrp/up/ettx901295data.htm
(not sure if this site is accurate as all the TTGX on this site are listed as 28" wheels. :

ETTX straight sill - wheelsize ?
http://crcyc.railfan.net/crrs/auto/ettx800648.jpg

Low slung ETTX with "straight" sill:
http://crcyc.railfan.net/crrs/auto/ettx850452.jpg

Interesting 1979 photo of a car built in 1977 (looks like it has "cut-outs"):
http://southern.railfan.net/images/archive/southern/freight/autorack/sou159118.html

Mark
(I have no real stake in this, these are out of my era )

[bbussey]

Of the current N auto rack models, the only one that should ride on 28" wheels is the EXR Vert-A-Pak.  Theoretically some of the Athearn Auto-Max cars would have 28" wheels depending on the prototype, but in all likelihood the model was based on a prototype with 33" wheels.  The remaining MTL and RC cars should be on 33" wheels.

[Mark5]

I guess I'll take my question to a proto forum.

Sticking strictly to prototype, it seems that we are saying that all enclosed Tri-level autoracks run on 28" wheels. ???

[edit to insert tri-level, which is what I meant]