Comments on: Weighting Wagons to Represent Prototypical Weights. A Good Idea or Not?

By: M

Mon, 10 Feb 2020 16:12:35 +0000

Everything you wanted to know about NMRA. What you want is RP-20. Please note that it’s a Recommended Practice, not a Standard. Hence is open to interpretation. As to whether light or heavy cars. Like I said. Try to make sure all the cars are in the same weight range. i.e. If NMRA says a car should weigh 5.5 ounces. Anywhere between 5 and 6 should be OK. And if you have a train of “say” 30 cars, 15 can be 5 ounces and 15 – 6 ounces; and you shouldn’t have any problems. But if you stick one car in there that weighs 4 or 7, you might get derailments. Also, as others have said, each car should be a good roller on it’s own. Wheels and couplers must be accurately measured. Hope this helps. Here’s the URL: http://www.nmra.org/index-nmra-standards-and-recommended-practices

By: Neville Parry

Neville Parry — Mon, 27 Jan 2020 16:31:06 +0000

Sorry if I’m a bit late adding my comments here, but I have a completely different slant on the this discussion:

The most important factor in this subject is the rolling resistance of the individual vehicles, not the weight! This is very much lower in modern models than it was in models built a number of years ago. This was pointed out to me forty ago with a train of passenger cars with a mixture of (heavy) brass body work cars and (light0 unweighted plastic kit cars. All the cars had approximately the same starting and rolling resistance, checked with a very gentle grade. All the vehicles had pin-point metal axles running in matched brass or quality plastic axleboxes.(This was a little revolutionary in the UK at the time.) The train could be pushed or pulled round fairly tight curves (~24″ radius) and through complex trackwork without any derailments. Light vehicles were not pulled inwards when being pulled or outwards when being pushed.
Another important factor is the smooth running of the locomotive – gentle acceleration and braking (no jerks) – even on the prototype, a full emergency brake application could cause a derailment.
The actual weight of the vehicles in a train will affect the ability of a loco to pull the train up a grade.
On the prototype, trains should always be started very gently, and full power should not applied until it is known that all vehicles are moving.

By: John lebsanft

John lebsanft — Fri, 24 Jan 2020 10:23:49 +0000

How does NMRA weigh their cars ? Over actual body length , over couplers, or what . I have never ever really understood.

By: David Stokes

David Stokes — Wed, 22 Jan 2020 21:20:13 +0000

Please don’t be disappointed by the responses to your question, but, yes, you are wasting your time and effort. Model locos don’t weigh the same or have the same tractive power as the real thing, so wagons that do will make for very short trains. The NMRA recommended weight standards were created after a long and complicated process and work well.

By: Joe deBy

Joe deBy — Wed, 22 Jan 2020 16:02:26 +0000

Many many years ago after building an all wood boxcar I found cars do not need to be weighted IF they ride on good wheels and good track. As a result, where possible, cars on the C & G are based on a weight of 65 grams for a 40′ car. Ruling grade is no more than 2%. Minimum radius is 24 inches. This lets me run 18 – 20 car trains. On rare occasions I use a Model Power F2A on the head and a F2B 17 cars back lets me run 35 car trains.

By: Steve

Steve — Wed, 22 Jan 2020 07:51:42 +0000

Hi If your trying to simulate the correct weight the best way is to use wagons full of the material you want, for example a wagon full of ballast etc.

By: YVES DURANCEAU

YVES DURANCEAU — Wed, 22 Jan 2020 02:34:50 +0000

Try moving some cars in your curves, you will see which cars are too light because the loco will push those cars offtrack. So try Pulling and pushing cars .Then add weight to solve the problem. NMRA guideline is useful. Use as little as possible as long as the cars stays on track.

By: phil johnson

phil johnson — Tue, 21 Jan 2020 23:47:31 +0000

Weight is a wonderful if you’re a locomotive. However, not for the cars it must haul. The heavier the cars, the less you can pull. The sharper the curves the less you can pull, also. most of my 40′ cars are between 4-4.5 ounces. NMRA has a chart for car weights and lengths

By: Morgan Bilbo

Morgan Bilbo — Tue, 21 Jan 2020 23:44:46 +0000

The best advice I can give, or suggest. Is to be sure the cars as weighed on a scale, are as close to each other in weight as you can. A train of light cars will do as well as a train of heavy cars just as long as you don’t mix them. i.e. Use the NMRA weights as a standard, get each car as close to that as you can. (? Or want to? Some like their cars lighter and some like them heavier than NMRA.) So what this is saying is whatever “proto weights” you add, just be sure the total weight is not too much. Remember: a model of a transformer does not have to weigh a proto weight, it merely has to look as though it does. Last item. The longer a train, the better the heavier cars will do. I’m talking about 100 cars. At that length, they must be NMRA or heavier. But again, not too much heavier. Is this clear?