I try to keep all my freight cars right at the NMRA reccomended weight.
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I have three Athearn Blue Box pulpwood cars that I bought the beautiful Chooch loads for. The problem is the loads make the cars VERY overwieght.
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So… I drill seven 1/2" holes about 3/4" deep into one of the loads to lighten it. The problem is the load makes the car come in at 6 ounces, which is still about 2 ounces too heavy.
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I don’t want to fully hollow out the load. I have done that on other loads, and it really takes a toll on a cutter bit to remove that much resin.
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What problems can I expect by having these cars 2 ounces too heavy? Obviously they will take more effort to pull up grade, but is there anything else to be conerned about?
You might need more engines to pull the train due to car weight.
Just as on the 1:1 railroads, you have to watch out for stringlining, cars being pulled off the tracks especailly around curves if you put a light car (e.g. empty well or 89 foot flat cars) or short cars (e.g empty ore jennies) ahead of a heavy car.
All you have to do is watch your car placement when you are running heavy cars and you should be ok.
There have been several threads on other sites where individuals are over weighting their cars on purpose (2-3oz). It had to do with better tracking and less yo-yo effect. If you are trying to pull a lot of cars over a 4% grade it might be an issue but on level grade it might give you better performance.
I would not expect too many problems with a car that is overweight by that amount, assuming the trucks are free-rolling and the couplers are not too rigidly mounted. I too try to follow the NMRA standards as much as possible but there are cars on both ends of the weight spectrum which just stubbornly can’t be made to conform and for the most part they do not raise issues, unless they have other attributes (or the layout does, such as very tight curves on grades) that push things to an extreme. Many flat cars and gons are all but impossible to weight to the standards yet run fine, even when placed near the front of a train.
To be sure at some point “things happen” which is why there are NMRA standards to begin with.
Personally I wouldn’t sweat a couple oz heavier than NMRA standards.
I have a few cars that are more than a couple oz overweight on my ISL and like their behavior on the rails, they don’t run away when coupling, better tracking and much less herky jerkiness. It is my intention to eventually overweight as much of my rolling stock roster as possible.
As Rusteespikes says there are many folks who are proponents of overweight cars, one is prominent modeler Mike Confalone. Mike likes operating cars that weigh 10oz or more on his Alagash railway and reports no problems running them with cars of lesser weight.
I have a lot of cars that are over weight. This is by design. My layout is not big enough to have trains longer than 31 cars including the engines. By having the heavy cars, I need multiple engines or pushers to make the grades on my layout. I suppose I could run light weight cars and use dummy engine, but where’s the fun in that.
I’ve run Rivarossi passenger cars at 12-15oz., but later removed some of the weight due to concerns over the axle ends wearing out the soft plastic journals on the trucks. The cars certainly rolled nicely, though.
This Walthers GSC flatcar weighs 6oz.:
…and this ConCor gondola 6.5oz.
…while this modified Athearn boxcar tips the scales at 7.5oz.:
While not all of my cars are this heavy, it’s the ones which are too light which cause problems…usually empty hoppers. They’re okay as a solid train, but when run with heavier cars, I like to keep them near the rear of the train.
When I run loaded hoppers, all weigh 8oz., as I use “live” loads (Black Beauty blasting medium). Most trains run doubleheaded, and sometimes with pushers, too.
The real question is do we need a outdated RP? RP20.1 came into existence in the wooden car kit with no weight and non-weighted plastic cars with plastic wheels that rolled like the brakes was set at best era?
I’ve never used RP 20.1 and never had any issues and only one of the clubs I was a member actually tried to follow RP20.1 and found most members cars wasn’t up to that RP.
I do add 2 stick on weights on the floor above the trucks and use metal wheels.
That resin they use is rock-hard too. Not easy to drill at all. If it was softer I would set of a jig and use a router with a 3/4" rabbet bit and make short work of it.
Well, I have rarely added weight to my stock kits to bring them up to EnemaRay standards and don’t have issues with derailing or stringlining, etc. I use the standard weights that come with cars like Stewart hoppers and run them just fine.
The only cars I have had a few derailments with were a pair of plastic Varney flats and replacing the trucks with brass ones cured their tendency to derail. No other weight was needed.
When I build any wooden or resin cars I add some A-line stick on weights but have never weighed them or checked for the RP standar weight.
I use Walthers code 83 flex and turnouts with #4 & #5 turnouts with a 24"R curve everywhere and my track isn’t perfect by any means or standard!
Roger,Some times I think out loud recalling the featherweight wooden car kits and plastic Varney and Hobbyline kits that weigh in at a ounce with trucks with deep flanges that rolled like a sled on gravel. RP20.1 was surely needed during that time frame then came improved plastic kits with weight and smooth rolling RP25 wheels with small flanges that in some ways made C-100 track obsolete-no foul intended I still use C-100 for several reasons…
Another thought of mine would be the difference in weight( per RP20.1) between modern cars that’s between 50’-89’ all in the same drag not including intermodal well cars.
Is RP20.1 outdated? Maybe… Should we have a better weighing system for modern cars? Perhaps.
Important to remember Recommended Practices are just that - recommendations or general guidelines, not hard and fast rules. Generally, as several folks have already noted, and ounce or two either way from the recommended weight isn’t a big deal.
My layout is small and like South Penn my max is about 30 cars. I add two to four ounces of weight to all of my rolling stock. I have 3½% grades with a 28” radius and I’ve never had a problem. I add as much as 10 ounces to my locomotives to add the needed traction to pull the over weight cars. The only exceptions are my Shays, no room for added weight.
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I do lub the axles with about a pin head of Permatex White Lithium Grease (WL-9).
Mel
Modeling the early to mid 1950s SP in HO scale since 1951
I think car weighing standards based on consistency and car length make sense as a concept, and I am not aware that following the NMRA RP standards has given anybody problems … other than the difficulty or challenge of living up to the standards!
As I posted above I have cars that are both (slightly) over and (sometimes seriously) under the standards and they seem to run fine and play nice together. I can imagine scenarios where the luck of the draw would put together a train which has too many outliers from the standards, or places them in an “unlucky” order in the train, or has exactly the wrong car coupled to the locomotives, and perhaps then I would have problems and would regret varying as much as I do (which is not all that much) from the RP.
I have very generous curves, few grades, and I do not use pushers on my trains, but many guys do. Nor do I run trains of prototype length for practical reasons. I suspect few of us do run 50 to 120 car trains, at least in HO. The guys who put together the RP standards were likely thinking of more than just Varney cars, but rather of the fact that our layouts put rolling stock through a torture test compared to the prototype.
I got one of those cars! As for me I never cared about car weight, never seemed to make a difference except once on a wood flatcar, that car was very light but come to think about it, I think it may have had original trucks too.
I have some cars that the loads make them over weight but I’ve never had any problems with them. The Chooch lumber loads I installed in double door boxcars are heavy and I have to add weight to the other side to keep the cars balanced. I only put them on one side so they can be seen when unloading at the lumber store. I keep the factory weight in the car because it helps keep the model rigid so it doesn’t sag.!http://www.trainweb.org/lonewolfsantafe/lp52019.jpg
It’s underweight cars that have problems, specifically the old Athearn Impact spine cars which are extremely light when they are empty. They have to go on the rear of the train, but isn’t that how it is supposed to be anyway, empties in the back.
OK, it sounds like I should not expect any problems. That is good news. I suppose that if out of 150 freight cars only three are overweight I should be OK.
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None of my cars are underweight. I have really been a stickler for the NMRA RP.
