So while I can't make Trainfest, I will baracade(sp?) myself in the train room for the weekend. So while I'm down there, I thought I would install FVM 36" wheelsets on some traincars. I have been told that anything rated at a capy of 200,000 or more should have them. Vunderbar! But like I'm not so good at reading that dern tiny printing. But my eyes are good enough to see what freight car types are on the tracks in front of me (mostly). As a general rule, I have been told that modern coal, grain, and aggregate hoppers should have 36" wheels. I was also told that 50' paper boxcars got em too. I can just make out a Ld limit on some of my centerbeam cars as being 200,000 or more. Does that mean that most centerbeams use them too? Likewise, my paper slurry tankcars (atlas) seem to have Ld limits well over 200,000. Should I place 36" wheel sets under them as well? Help please Ta.
I use a small magnifying glass for reading the small print. If the LD LMT and LTWT add up to 263000, then 36" wheels.
Thanks for the question. I am going down this path, too, and trying to get my hands around what car gets what wheels. NOTE: The information below is work-in-progress. Only cars BOLDED are confirmed 100% correct. I will be adding to the list and updating it as I get the research done. I don't mean to hijack the thread, I'm hoping this will help others with similar questions. I'm gonna post my standard roster staples so I can make sure I am getting this right: Atlas Coalveyor - 36" Kato/DI/LBF Coalporters/Aluminators/Aeroflows - 36" Atlas/M-T 100T 3-Bay Hoppers - 36" IM 5161 Covered Hoppers - 36" Trainworx 100T Quad Hoppers - 36" Atlas Corn Syrup Cars - 36" Atlas Kaolin Cars - 36" IM 4727/ Covered Hoppers - 36" RC Centerbeams - 36" RC Beer Cars - 36" RC Reefers - 33" (Similar Cars have 36") Standard MDC/Athearn/Atlas/IM/FVM 50' Boxcars - 33" DI Maxi-III 33" Ends/38" Intermediate DI LoPac 2000 33" Ends/36" Intermediate DI Twinstack 33" Ends/36" Intermediate To further complicate matters, and assuming I have my facts straight, Micro-Trains does not make a true 100-ton truck. So putting the 36" wheels on M-T trucks isn't 100% accurate, as the 70T truck is smaller than the 100T. (here is a post that is one source of info I used... http://therailwire.net/smf/index.php?topic=11535 )Atlas does make a correct 100-ton truck, although some have said the detail isn't as good as M-T's. Plus you are stuck with Accumates or body mounting M-T's. Keep in mind, this is all pretty nitpicky stuff, but I just wanted to comment about it. If you are going to the trouble of upgrading to 36" wheels in the first place, then you probably care about this--at some level--I would suspect. What I plan to do is start upgrading my "Tier 1" 100T cars to body mounts and Atlas trucks and then move the M-T truck/coupler combos to any cars still needing conversion, and also replace the rest of the wheels with 33" or whatever is appropriate.
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) 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.
Thanks sundowner. FYI, if anyone else has updates, just PM me (or, at least don't quote the list if you want to reply) and I'll change the post. That way we don't have a bunch of quoted copies of the post that aren't being updated. Thanks. (Not trying to be an ingrate there, sundowner. Hope it doesn't come across that way. I do appreciate the info)
Are 33 and 36 inch freight car wheels the only options in the USA? Are there any 28 inch wheels? Thanks.
Ok, Someone clarify this for me. If a car is stenciled capy 1400000 that's 70 tons, So it can use 33 inch wheels? What if the capy is 141000? that is over 70 tons so would it need 36 inch wheels? In other words, What is the cross over point from 33 inch to 36 inch?....dave
There's 28" and 38" From my above linked to TO thread... 28” 48750 lbs 33” 55000 lbs 36” 65750 lbs 38” 78750 lbs
There was a pic in one of the n-scale mags that FVM is working on a 28" wheel so hopefully that will be coming soon and that they get caught up on the back orders too.
There are 5 sizes of freight car wheels in use in the USA: 28", 30", 33", 36", 38". The 30" wheels are rather rare. The allowable weight of a railcar and its lading is determined by the size of its bearings as well as the size and design of its wheels. Here are allowable weights for the most common designs: 28" : 50T, 70T 30" : 50T, 100T 33" : 50T, 70T, 100T 36" : 100T 38" : 125T For a given weight, a larger wheel places a lower stress on the rail which is desirable. However a smaller wheel can be used to lower car height or center of gravity which is also desirable. When choosing the correct wheels for a model it is best to have info on the prototype, but for modern non-intermodal equipment if you can read the stenciling on the car, add the LD.LMT. to the LT.WT. and you should get one of the following numbers: 220,000 = 70T car, use 33" wheels 263,000 = 100T car, use 36" wheels 286,000 = 110T car, use 36" wheels 315,000 = 125T car, use 38" wheels This will not work for intermodal equipment, but will get you the correct wheels for other cars more than 99% of the time. Remember, there are always exceptions to any rule. For example, there are 100T cars with 38" wheels. Red Caboose centerbeams and "beer cars" should all have 36" wheels. Red Caboose 57' reefers are based on a 70T prototype and should have 33" wheels, however there are very similar cars that are 100T cars with 36" wheels. Early 5 unit articulated well cars such as Twin-Stacks and LoPac-2000's should have 33" wheels on the end trucks and 36" wheels on the intermediate trucks. Later cars such as Maxi-III's have 33" wheels on the ends and 38" wheels on the intermediates.
Thanks for the explanation. I've got another question...Are these the maximum for the wheel size? For instance if the numbers add up to say 225,000 would the car require 36 inch wheels? or do the railroads only label the cars to add up to these specific numbered steps? ....dave
Those numbers are the maximum allowable gross weight on rail for a railcar based on the bearing size. (286,000 lb cars use the same size bearings as 263,000 lb cars. The additional weight is allowed due to a stronger carbody design.) You take the maximum allowable gross weight on rail, subtract the light weight of the car and the remainder is the load limit of the car. Therefore, the load limit and light weight should add up to one of these five numbers (There are still a few 50 ton cars running around and I omitted them from my previous post): 177,000 = 50T car 220,000 = 70T car 263,000 = 100T car 286,000 = 110T car 315,000 = 125T car Of course, to every rule there are exceptions. A car owner may reduce the load limit below the maximum allowed based on bearing size. This most commonly occurs when structural limitations of a car prevent it from carrying the full amount of weight that the bearings are designed to carry. When this is done, a five pointed star is stenciled next to the LD LMT. For an example of this, look at an 89' flatcar - especially one under an autorack. So, if the LD LMT and LT WT add up to 225,000, you have either a "100 ton" car with a reduced load limit (confirmed by a star stenciled next to the load limit number) or you have a car with a stenciling error. While there are many different combinations of bearing and wheel sizes on prototype cars, generally 177,000 lb and 220,000 lb cars will have 33" wheels (or 28" on low deck autoracks and a few tofc/cofc cars). 263,000 lb and 286,000 lb cars will have 36" wheels and 315,000 lb cars will have 38" wheels.
Oops. Thanks for the correction. I completely forgot about those. I model pre-1954 and must be more careful when I write about this strange modern stuff.
ATSF, Thanks for the great explanation. I've always wondered exactly how these numbers worked and now I know. I'll print it out and put it in my modeling info file.....dave
Cool thing about the Kato 33" and 38" wheels is that they fit the DI Maxi-III trucks. The bad thing is that it cost about $20 a car for the 38", but they look cool . I hope FVM comes out with the 28" and 38" wheels soon.
I'm guessing the thread I pointed to wasn't read... Trainorders.com Railroad Center Anyway... here it is in full "As an aside, axle limits and axle loading are not the same thing... axle loading is used to denote the max axle load a rail structure (be it a bridge, right-of-way, etc) can take, in the US, it's ~ 40 tons. Axle limit is the amount of weight an axle can apply to the rail, which in the end cannot exceed axle loading. Axle limits are determined by bearing size and wheel diameter. For freight cars, there are seven AAR axle and bearing sizes in use... note all new 286K cars are required to use Class G, K or M axles. Class L is the new replacement for Class E, Class K is the new replacment for Class F, and Class M is the new replacement for Class G (though as noted, not required). All the newer axles/bearings are shorter to reduce flexing under load. D 5.5” x 10” 44250 lbs per axle E 6” x 11” 55000 lbs per axle F 6.5” x 12” 66000 - 71500 lbs per axle G 7” x 12” 78750 lbs per axle K 6.5” x 9” 71500 lbs per axle L 6” x 8” 55000lbs per axle M 7” x 9” 78750 lbs per axle Class B, 4.25" x 8" (26000 lbs)and Class C, 5" x 9" (35500 lbs) are older outdated classes, there was a Class A, but I don't know it's dimensions, just that it had a 16500 lb capacity back before 1961. Freight car wheel sizes and their respective maximum capacities per axle: 28” 48750 lbs 33” 55000 lbs 36” 65750 lbs 38” 78750 lbs Locomotives typically use Class GG bearings and 40" or larger wheels, and currently have a max capacity of 72000 lbs per axle." "I also forgot to mention truck (bogie) axle spacing, which goes along with rresors write-up on axle spacing. For two-axle trucks: 5' 6" (220001 lbs - 263K) 5' 8" (286K) 5' 10" (286001 lbs to 315K) AAR raised axle limits on all axles in 1963, for Class F bearings, loading went from 251K to 263K, which then allowed most cars to carry 100T." I've never seen a reference to a 30" wheel... if there was one, they not produced now. Also, there are 36" wheels that allow a 315K GRL, but they have to be inspected regularly, as they will condemn past a certain rim thickness (1.375" IIRC)
