Weighting (NMRA standards)


Toolbelt

Active Member
When weighting a caboose, do you measure the body length only, or include the front and rear porches in the length measurement? Also, any quick/easy methods for adding weight to a tank car? Mine has a narrow spine that is too small to hide any weighting in. I've heard of inserting ball bearings or sand after drilling a hole in the underside of the tank. Any other creative methods? It's only a 41' tanker and has a low center of gravity, and is likely my smoothest rolling car. Can I get away with just running it "as is"?
 
When weighting a caboose, do you measure the body length only, or include the front and rear porches in the length measurement? Also, any quick/easy methods for adding weight to a tank car? Mine has a narrow spine that is too small to hide any weighting in. I've heard of inserting ball bearings or sand after drilling a hole in the underside of the tank. Any other creative methods? It's only a 41' tanker and has a low center of gravity, and is likely my smoothest rolling car. Can I get away with just running it "as is"?
I add the porches to the length of cabooses.
Many tank cars have removable ends. If they're not glued in place, an Exacto blade can be inserted and the end can be pried off. I use a #17 blade. Then you can add weight. I glue stacks of pennies together and then glue the stack inside before replacing the end. In some cases, you may have to remove the handrail first, and then put it back on.
In many cases, you can run a car "as is" without a problem. Run it towards the end of the train. If you are not running long trains, it may not matter where you place it.
 
I always thought the recommended weight was a bit high but totally depends on the car.
I have drilled holes in the bottom of tankcars and added bb's and white glue inside.
Cabooses usually don’t need much weight but I believe most measure length from the coupler boxes which would include the porches as Willie says.
 
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I always thought the recommended weight was a bit high but totally depends on the car.
My rolling stock is a mix of mid-grade Athearn, Bachman and Accurail from the 80's and in most cases I had to add between 1/2 to 1 oz of additional weight to each unit. In one closed hopper, it required an additional 1.25 oz. The cars feel heavy but roll much smoother and carry more momentum. As I'm in the process of doing my entire 15 unit fleet, my layout is out of service, but I'm curious if the added weight will affect loco performance. I realize that car weight is not the same as lateral pulling weight/rolling resistance but their is some relationship between the two. Luckily my layout is flat with 0 grade but I can only imagine the loco strain on some layouts with grade pulling 15-30 cars.
 
I agree the heavier cars do roll nicer, especially the Accurail.
With 0 grades I’d think the only increase in drag might be a tight curve.
My layout has two percent grades so anything over a dozen cars or so usually gets another loco.
A friend overweighted his rolling stock, they did roll nice but the added weight made the spinning axel ends cut into the plastic trucks pretty deep!
 
Also curious if all the main brands today, mid-grade and higher, adhere to NMRA standards as far as weighting? Does one need to still tweak brand new modern cars right out of the box?
 
Also curious if all the main brands today, mid-grade and higher, adhere to NMRA standards as far as weighting? Does one need to still tweak brand new modern cars right out of the box?
Mostly no from my experience regarding weight. I still weigh them as part of my initial inspection which also includes checking coupler height, trip pin height, using the truck tuner on all sideframes and checking tightness of the trucks, one looser than the other. On the higher grade cars, I also double-check that all add-on parts are secure.
 
Mostly no from my experience regarding weight. I still weigh them as part of my initial inspection which also includes checking coupler height, trip pin height, using the truck tuner on all sideframes and checking tightness of the trucks, one looser than the other. On the higher grade cars, I also double-check that all add-on parts are secure.
I realize that things can happen when fragile objects are shipped, but when manufacturers are charging $45-$80 for essentially a plastic model of fairly simple complexity (in most cases), it should come with some responsibility on their part to meet certain uniform standards as far as weight, coupler setup and scale size. It's not like we're just buying some cheap $5 car from some obscure Chinese online seller.
 
I realize that things can happen when fragile objects are shipped, but when manufacturers are charging $45-$80 for essentially a plastic model of fairly simple complexity (in most cases), it should come with some responsibility on their part to meet certain uniform standards as far as weight, coupler setup and scale size. It's not like we're just buying some cheap $5 car from some obscure Chinese online seller.
I don't do it to check up on a manufacturer, I do it to ensure that everything is up to my standards.
 
As a follow-up, I'm in the process of tuning up the limited rolling stock I inherited, plus recent additions of used cars purchased at a local train show. After making sure everything had Kadee couplers, and metal wheels, I went through the process of verifying car weighting using NMRA standards (for HO). My cars are all from the 80's and 90's, and are mostly Athearn or Roundhouse, with a couple of Life-Like/Model Power, or Accurail thrown in, while some are unidentified brands. Some I upgraded for purely sentimental reasons. The fleet is mainly 40' boxcars, 33' open hoppers, 54/55' covered hoppers, with a flat car, 37' tank car, and gondolas. In total there are 20 cars plus a caboose. Based on NMRA standards, my fleet should have weighed in at 79.97oz, but came in at 64.02oz, a shortfall of 15.95oz. Using 1/4oz stick on wheel weights (Amazon), I was able to add 13oz in total. I did not add weight to the flatcar, tank car or caboose. 2 cars were originally at, or slightly above, the NMRA standard and required no additional weight. The added weight was divided by the remaining 16 cars. Some required 1/4oz while one required 1.75oz. The rest fell in between. I was worried if my old GP50 could pull the additional weight, so as an experiment, I kept adding cars and testing. Surprisingly, the GP50 (Athearn circa 1987) pulled my dummy GP38, all 20 cars plus the caboose with relative ease on my flat (other than warpage) 4 x 8 layout. The "train" 3/4 fills my outer mainline. Any longer, and the crew in the caboose would be eating with the engineer in the cab. lol I never intend to run that long a train, and my future layout (still a 4 x8) will have a switching yard so the cars will have lots of track to spread out on. For those with older fleets, it's never a bad time to check car weighting as there's likely a lot of underweight cars out there.
 
If you need to weight flats and similar cars, you can use lead tape with adhesive on one side. This allows to conform the weight and hide it under the sill.
 
When weighting a caboose, do you measure the body length only, or include the front and rear porches in the length measurement?

YES
Can I get away with just running it "as is"?
YES, unless it derails.
 
It's not like we're just buying some cheap $5 car from some obscure Chinese online seller.
Actually—We are. There are literally only a handful of manufacturers, almost universally located in China. And the car may start out there at $5-$10, but by the time everybody adds their profit onto it, including the Tax Man, you now have a $40 car. But nobody seems to want to hear that.
 
Actually—We are. There are literally only a handful of manufacturers, almost universally located in China. And the car may start out there at $5-$10, but by the time everybody adds their profit onto it, including the Tax Man, you now have a $40 car. But nobody seems to want to hear that.
Or, you do some work/modifications and get one for $16



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I put clear Plastruct in the windows, a bit of detail paint on the handrails and arcs, some decals from MicroScale, and they look pretty good.
 



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