my question is is there a formula to adding weight to frieght cars? I have an ho
lay out and am having problems with derailments.I also use body mount kay dee couplers. the formula I am using is 1ounce and 1/4 once per every inch. this seems to work o.k but i also have an elevation lift of 1 inch per 3 feet of track and i have a problem climbing this with my engine. my engine is a 2 year old athurn gp40 and is an allwheel drive with no rubber bands on the wheels I also added 2ounces to my engine. Im thinking the only way i can solve my problem is to take out my elevation lift and go with the same level. especially were this seems to be my only problem area and is a hard section to reach. if I put 10 cars on not weighted I can make the grade,If I ad weight including my dummy engine weighing 3 ounces i can only haul3 cars. I can haul probably 10 weighted on a level track with no problems.[:(!][:(!][:)]
Mike,
Here’s a link to the NMRA’s Recommended Practice on weighting cars:
http://www.nmra.org/standards/rp-20_1.html
You have a 3% grade and unless you are modeling a short line using Shays and other geared locos, that is a fairly stiff grade. Another recent post notes that prototype railroads try to avoid anything stiffer than a 1.5% ruling grade. If your cars are properly weighted, have easy to roll trucks with metal wheels and your track is clean, you may have reached the limit for your GP40.
Bob
NMRA Life 0543
Sorry, but you have just learned the limits of your engine. One or more of the variables will have to be adjusted if you would like to pull more cars. As previously suggested, check your cars for free-running wheels, and convert plastic to metal (get good wheel-sets). If that doesn’t work, you will have to reduce the grade, preferrably to less than 2% if you don’t want to buy another loco, or to consist.
To address the other end of the equation, which is the tractive effort of your locomotive. Adding weight is the answer. I’ve added up to 8 ounces of lead to a GP-60. As long as you can spin the wheels, you should be O.K. You may still run into heating problems with the motor, but so far I’ve been O.K.
I’ve added 12 ounces to each of my AC4400’s and now they pull like gangbusters!
Mark in Utah
On a real railroad, with loaded freight cars, a single GP40 could probably only handle 5-10 cars up a 3% grade - less if there are any curves on the grade. Only a few real mainline railroads had any grades like that - and each of those super-steep grades was treated as a special case. I remember reading in Trains about one super-steep grade, something like 5%, on the Southern that lasted into the SD60 era. Trains that had to go over that grade were tripled - i.e., broken up into three sections at the bottom of the grade, then each section taken up the hill separately, and the whole train reassembled at the top. A pair of engines that could comfortably handle a 45 car train on the “normal” grades (1% to 1.5%) were “down on their knees” at full throttle to pull just 15 cars - that’s only 7.5 cars per SD60 - up that grade.
We often have to have steeper grades than the prototype on our layouts. Frankly, since few of us have the space for 40-60 car trains, accepting the physical limits imposed on our models by steep grades can enhance realism, as a pair of GP40s hauling a 12 car train looks silly on flat land, but quite realistic in mountainous terrain.
Jim
Mike, the first thing I’d suggest, is lose the dummy engine. That’s taking the pulling power of 2 or 3 cars from the powered engine. I personally don’t own any dummies, if it doesn’t have a motor, it’s not a locomotive. Second, as was stated above, check the cars for free rolling trucks. Easiest way to do that is place the cars at the top of a grade (preferably not one as steep as 3%) and let go of them, one by one. They should accelerate to the bottom and coast a ways on the flat area. Finally before trying the grade again, wipe down the rail heads with a paper towel with rubbing alcohol on it to remove any oily residue. If there’s much oil on the rails, you may be over lubricating the locomotives. This, of course, will drastically reduce the traction of the locomotive on the grade.
Now the derailment question. Since you didn’t say where on the layout and what conditions, I’ll have to ask a few questions. What is the minimum radius of the track causing problems? How long of a car are we talking about here? Too sharp of a turn with body mounted couplers can cause this problem. It’s worse with long cars. Do you own an NMRA standards gauge? This is probably the best troubleshooting tool for finding these type problems. Never assume that the wheelsets or the track (especially switches and crossings) are in gauge. It comes with instructions on it’s use, or you can go to the NMRA webpage and find Recommended Practice 2 http://www.nmra.org/standards/rp2.html Most other problems will relate to trackwork quality, ie. smooth rail joints, smooth transition to vertical curves, etc.
You can write me directly if you have other questions. tadiehl@enter.net
Mike,
I have the NMRA RP-20.1 pasted on my layout room wall
‘N’ scale 1/2 oz + 0.15oz per 1" of car body length
‘Ho’ scale 1oz + 1/2oz per 1" of car body length
Bill
i would add more weight to the loco OR get 2 loco’s
N-scaler with no opportunity to add wait to the locos, that would be nice. I have a fair size fleet and all the cars have truck mounted couplers. I originaly put too much wieght in my cars but could not pull squat up a 2.5% grade, so I re-wieghted to nmra specs and was impressed. The extra wieght will help hide some derailment problem but the locos will find these issues eventally. So I would go back and check the trackwork and be critical of your work., it will yield many hours of more enjoyable running.
Exactly right. That’s the same formula I’ve been using for years.
[:0]Mark, I haven’t heard anyone use that term in a long time. I used it often with my kids, who are now in their 40’s. My dad used it often. You either had a dad using it or you are as old as I am! (70).[|)]
If I had a grade and problems getting up it, I would probably use a pusher. [:p]
Also metal wheelsets will add wait where its best, as low as possible. In ‘N’ I dont think it would add too much to a car.