I just finished weighing my entire fleet of rolling stock most of which weighed in a little on the light side.
So I corrected so far 20 freight cars using the standard 1oz. and 1/2oz. per each inch of car. I put a small consist of 20 cars together and they seem awefully heavy. At present I do not have any aprecable grades to speak of on this section of layout and a single locomotive is having a very hard time starting off the pull and I need to have the throttle some where around 20 to get her to keep moving.
Any suggestions? would you tend to keep the weight a little on the light side or as close to the exact weight as possible?
If your goal is to have cars track well and to minimize derailments, the NMRA recommended practice is a good place to start, in my experience. If you wish to pull as many cars as possible with a single engine, even if they occasionally derail when shoving them into spurs and through trackwork, then make the cars lighter.
You are correct - They do weigh a lot more. You should also use metal wheels and invest in a ‘truck tuner’ to make your trucks roll free. All of my cars are weighted as close as possible to the NMRA weighting(RP-20.1)
The key is that you have a base standard for your cars - they all weigh the same ‘in relation to their length’. My layout has 22" radius curves and 2.7% grades. A P2K GP9 will handle about 12-15 weighted cars up ‘the hill’. My Spectrun 2-8-0 with pull about 7-8 cars up that same grade. At our club, we have a 2% grade on a 33" radius curve - that same 2-8-0 will handle 15-17 free rolling cars. I know that my trains perform better with weighted cars(especially when switching).
All my cars are weighted to NMRA standards. They are also equipped with metal wheels. With this combination even heavy cars can roll easily. How easily? Three NMRA weighted HO covered hoppers on level track can be pulled by a June bug. If a single loco can’t pull twenty such cars I’d say that loco has some severe weight or power issues. My two SDP40F’s weigh in at nearly four pounds for the pair. Just one of them can easily pull twenty cars. My Athearn GP38-2’s are among the lightest locos I have and they too have no problem with such a load. On the other hand, my 4-6-0 Hall type weighs in at almost a pound and can’t pull three forty foot box cars without slipping.
Thanks most of my cars including the ones tested do have metal wheels and I have all the truck tuners and NMRA gages etc. I do think it’s time to visit the Kadee website and order some more fiber shim washers as I am noticing a lot of rock in a few cars so time to just bring everything up to spec so to speak. I figured out why the loco a cheap Bachmann GP 38 dcc onboard model was having a hard time. Seems my friend who thiks he is mr. DCC set the start voltage way too high. I went back and set everything to the default mode and it’s running fine. Aren’t friends great…lol
Sounds like the same problem I had with an SD40. One of my friends programmed it for ‘realistic’ operation. It took the darned thing almost 12 feet to get up to speed. I reset it to factory default an dreprogrammed it to run like my other locos. Yeah, friends can be a real hoot sometimes.
For the rocking cars, check the wheel sets and make certain the axles are long enough. At the club we replaced a bunch of plastic wheels then noticed this rocking problem. We discovered the new wheel’s axles were just a bit to short. The cars were rocking (actually slopping) back and forth on the axles in the “bearings” not on the bolsters. We changed out the wheel sets for some with longer axles and everything was good again.
One truck should be screwed tight enough to prevent wobble but loose enough for it to rotate easily. The other truck should have a screw less tight to allow for up and down movement. The tighter-screwed truck should prevent/reduce wobble while the looser-screwed truck will allow tracking over any unevenness of the tracks.
Well, I’m gonna bite curve here and say that R.P. is reccommended practice. As needed, you may need to shave off a bit of weight. Not so much as to undo all your work, but if the engine is having issues, some of it may need to go. Though I agree that the problem is in the loco. My Bachmanns out of the box will haul at least 10 cars at NMRA.
The NMRA RP is generally to heavy for many prototypes. For tension it can be shown the NMRA formula is not as good as using a simple length to mass ratio. I use a nominal 0.57g/mm (1/2oz per inch) for goods wagons and 0.47g/mm for passenger cars and empty block trains. ( which is within the range of the NOROP NEM) Also you can check if your wagons are free rolling. I classify a wagon to be free rolling if it can roll down a 1 in 50 grade from a standing start.
Some manufacturers make wheel trucks that are a little wider than others. Why this is done I don’t know. Maybe to make it harder to put a foreign wheelset in their product. As for the pizza cutter wheels, those are wheels with oversized flanges such as those used on many older cars and locos. I used to see many of these in my younger days back in the 60’s and 70’s. Pizza cutters were shown the door with the advent of code 83 track. While they work well on code 100 track they hit the spikes on code 83 as well as riding high on crossovers and turnouts.
I don’t believe that anyone answered this question. Yes, the tracks are the same distance apart. The problem is in the overall length of the axle, not just the portion between and under the wheels. Not all of the trucks are manufactured the same. So you may have a mismatch where the axle is too long, and the wheelset will bind in the truck axle. You can also end up with the condition where the axle is too short. In this case there will be too much slop in the assembly, and the truck will ride sideways until it is supported on the tapered axle end. If this happens the car will have a noticeable lean to one side even though the truck is otherwise mounted squarely to the bottom of the car.
Speaking of metal wheels that is exactly one thing I have encountered when changing out from plastic to metal another which I just found was and now I may be doing something wrong here but how many different sized wheels are there? I was under the impression 33" for freight cars and 36" for passenger cars I put a micrometer to a set of plastic wheels that came off a Athearn box kit and the wheels were smaller then the 33" whats with that?
I stopped weighting cars to NMRA RP’s a while back. I use a standard that is about 80% of the NMRA RP now that all my equipment has very free rolling trucks. The more free rolling the trucks, the less need to “anchor” the cars down to keep them on track through turnouts, curves or when backing.
Very free rolling trucks and slighly lighter cars - the secret to greatly improved pulling ablity of my loco fleet.
This may be just coincidental, but the weight of a loaded 40-foot boxcar, say a total of 140,000 lb., when reduced by a factor of 87.1 three times (140,000 / 87.1 / 87.1 / 87.1) comes out to very close to the NMRA-recommended weight of 3.5 oz. for HO scale…
Terry,I agree RP20.1 is to heavy and is outdated…RP20.1 dates back to the light wooden car kits(no weight included),light weight plastic cars (like Varneys),poor wheels and poor track.
The best solution for trouble free operation is not RP20.1 but,accepting nothing less then derailment free operation which is attainable through smooth track work,correctly
I have 24 coal hoppers and 12 ore cars all weighted to the standard in a 36 car lashup plus caboose and my Bachman 2-8-0 handles it no problem on a 22"radius–wheels are metal
I normally run 7-12 cars plus caboose a I only have a 4X10 but I wanted to see what the 2-8-0 would do
Maybe I will add my 5 box and 5 gondolas all weighted to standard and see what happens (if they fit on the oval)
I just went and bought this scale from Harbour Freight. For only $13.00 you can’t beat it. It will weight up to 11lbs. The car I have on it measures 12.5" from end to end. So if I am doing this right it weights 7.30oz. Which should be correct. I am going to do this and adjust all my cars from now on. Is there a standard for Steam Engines, I have one that’s real heavy. Look below, and that’s OUNCES.
Mike I use something very similar except it cost a hell of a lot more or should I say at least it did when my old company purchased it. I used to work for a alternative energy compnay that went belly up so they had an employee only yard sale so to speak and I picked up four place digital balances for $25.00 ea that sold new for around $1200 I also bought a bunchof those magnifing lights. Not the cheapy one’s but thses sold for around $195.00 in McMaster.com I know becasue I purchased them for the company, along with a bunch of electronic equipment, a resistance soldering tool and some goodies SWEET DEAL. back to the subject at hand. I started weighing locomotives and adding up the weight of an entire consist, I gave up. I now think the NMRA standard is a good benchmark or reference point but feel it’s just a little too much on the heavy side. Your math seems right on the money as well. I had to scratch my head on a few cars and say no way thats way too heavey. I had another money wrench thrown in the works today when I weighed a few Atheran ready to run cars that came with equipment loads and not only had metal wheels but the flat cars themselves were made of metal. Each car was about 6.5 oz. over the standard now what do you do with that? I was about to take a dremel tool to the bottom side of the one load and started lightening it up but thought better of it.
