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Weights of Cars and Position in Consist
Janelle is working with her hubby on their new HO layout and asks:
“I gather real railroad trains run with a mix of fully loaded tankers and cars and lighter empty flatcars without adverse results like derailing? My guess also is that running lighter-weight cars would be more at risk of causing a derailment than heavy cars. If my assumption is correct, how then will this apply to trains on our new model railroad, and what would be the ideal weights and position for cars behind the locomotive? Any sharing of knowledge would be greatly appreciated.”
6 Responses to Weights of Cars and Position in Consist
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Janelle
To simulate prototypical ops I leave unloaded cars towards the rear and heavily loaded cars toward the front. Fuel cars are never directly attached to the loco.
In reality on your layout the cars should weigh almost the same loaded or empty. Look to the NMRA Standard and Practices. You will find what you are looking for in Recommended Practise 20. Some view these as a minimum and will deliberately exceed these recommendations.
Sadly the bloke to answer this question expertly and with added humour passed away a couple of years ago. Cliff Olds worked for most railways in Oz, starting as a boy loco cleaner and retiring as the Chief Train Controller of the South Australian/Australian National Railways in SA, His breadth of experience in all facets of railway working was amazing, and his willingness to share unbounded.
Go to NMRA.com. This is the “governing body” for NA hobby. They have RP’s (recommended practices) and they have tables for adding weight to cars..
Actually, the real railroads have similar issues. That’s why every car has markings for base weight and for load limit. I recommend that you check the weight standards for freight cars on the NMRA website. Once you know the recommended weights you should make sure all your cars are in specification. For flat cars, hoppers, and gondolas you should include any loads in the car’s weight. You’re correct in that light cars may tend to derail on curves and turnouts while heavy cars will limit the number the loco can haul.
I will be honest, I don’t know how placement is determined in the real world. However, I have learned, over my 30 years in the hobby and some 4% grades, not to put light cars near the front. With my inclines, lighter cars can be pushed off the rails going down the grades. All my rolling stock is weighted to NMRA standards, plus. If a piece of rolling stock should be 5 1/2 oz, I will weight it to 6oz. I would rather be slightly heavier, than a little light. I use BlueRail to control my locos, so setting up a MU is quite simple. Glenn
In the real world, railways/railroads generally have much larger radius curves than we can manage on our models. There is however another difference that is very infrequently mentioned – rolling resistance. The rolling resistance of modern prototype vehicles is very low due to the use of roller bearings checked regularly by hot-box detectors. High rolling resistance on the model can be partially alleviated by using steel axles with pointed ends rolling in brass bearings. I have not looked at how this compares when things are scaled, but I have hardly ever seen problems with light/heavy stock equipped this way. My personal experience is that with well-laid track, I have minimal problems with (UK) models, both passenger and goods, that have had additional weights removed.