I weigh my equipment with the following simple formula.
Cars: 1 OZ. per runing 10 scale foot From end beam to end beam. E.G. a 53’ foot baox car would be 5 ounces. I use an old weight watchers spring scale. And to measure the tractive effort by just have the engines push against the scale. A 40 Box car would be 4 Oz. I buy the fishing weights from Wal Mart. Use a 21 ounce hammer to pound them into shape tha’ll fit and a flat head ball pean hammer to get the exact shape and small projects glue to cement them into into place.
locomotives up to 2 ounces per running 10 scale feet. Or as much as you put in to it. Locos like an RS 3 would of course be weigh less due to it’s limited space. Switchers would be as much as one can. I have an SD45 that weighs 18 ounces. And a GP 7 that weighs 10 ounces. And an AC 4400 weighs 21 ounces.
Cabooses and MW equipment is 1/2 ounce per running scale 10 feet. A 40 box car would weight 2 to 3 ounces.
I’ve been to friends layouts where they have taken out the weights and thier cars derail all over the place. Can’t keep them on the track at all. Put one of my cars, not one speck of trouble. It takes more power to pull my cars but they run and DO NOT DERAIL! The point is don’t over weigh but do so to keep them from derailing. They’ll run smoother and won’t derail. Check your wheels gauge and coupeler height gauge and of course the track work. Model railroading suppose to be fun but keep up the maintance and you’ll have fun. Practice Murphology and he’ll go away!
Your engine scheme does put maximum weight over the drivers, but the other important thing to remember is you do not want to overload the motor. A basic rule is that the wheels should still spin at maximum voltage if you keep the engine from moving forward(block it with your hand). If it cannot still spin it’s wheels, you take a chance on burning out the motor. If you have specs on the the motor, do not exceed the maximum amps…
Your car weighting should work, but it is a little ‘heavy’ compared to the NMRA 'RP-20.1":
On the MDC RS-3 that I have the body is a singel peice with no breaks in it. The cab fits over this. I’m eventually going to take the body off with the cab on it an dfill the cab with Temp-Low. That should provide a good bit of weight.
I weight my cars about the same as the original poster. I use one ounce per 10 scale feet of car length. There is a 3.5 ounce minimum for cars under 35 scale feet and a 7 ounce maximum for cars over 70 scale feet.
Additional weight is added to the locomotives but as was mentioned don’t go too far with weight as that can burn up motors and cause drive problems. I usually only add a couple of ounces or so to locomotives.
Free rolling trucks are also needed. Trucks that don’t roll freely cause drag that limits the length of trains the locomotives can pull. I use Kadee trucks only the exception being where Kadee dosen’t make the correct truck. In that case Kadee wheels are used in the correct truck.
The NMRA and I have been happy with their weight standard for years. As for locomotives…
Something over a half-century ago, the then-Editor of MR (John Page?) wrote an editorial about scale-weighting locomotives, to match model pulling power to prototype peformance. He ended up REMOVING weight from a B&O Dockside 0-4-0T so it wouldn’t pull the same length train as his 2-8-0.
If a single six-axle unit is physically capable of taking your shorter-than-scale unit train the full length of your main track, do you really need a second unit? Or helpers on the one long grade?
My own most guilty performer is an 0-4-0T, model of a 1880s Hanomag loco that lasted into the mid-1960s at a Hokkaido coal mine. The superstructure is a lead casting (!) and it can out-pull my 0-8-0T, which has added weight. The prototype couldn’t do that in its wildest dreams.
Most of the high points have already been covered, only one thing to add.
Lead shot has its place, but Elmer’s, especially a thin mix, may not withstand that kind of mass energy combination, and then you have loose shot all over your layout room, not the ideal solution.
Lead machining generally doesn’t make for much dust, but its a little hard to whittle from big pieces.
Commercial weights are useful, but may not fit the space available. Good trick for steamers are lead toolboxes, disguised as wood.
A very handy solution is the thin lead sheets. You can fit a significant amount of weight into a tight space using a large planar area. Cab floors and ceilings, under and atop pilot beams, a thin sheet will fit into many places easier than alternatives. You could hassle out a method for a cast weight inside your sand domes without melting them, but you’d achieve similar effect just raising the cab floor and dropping the ceiling a thirty second of an inch each.
Remember symmetry in weighting. Steamers popping wheelies are not prototypical, and you can actually lower tractive ability with unbalanced weighting.
Any HO scale locomotive with a decent-quality motor can handle more ballast than is possible to hide inside of it. While trying to determine ways to improve the pulling power of the Athearn Mikado, I tested one with a 21 ounce lead “saddle” draped over its boiler, and it was still able to slip its drivers easily. On the other hand, an old Tyco C-630, with a cheap motor mounted-on and powering only one truck, was unable to spin its wheels with less than 10 oz. of extra weight.