Jim Bernier’s posting has it pretty solid. I follow the NMRA recommendations (1 oz plus 0.5 oz per inch of length) for car weighting. Too light cars will derail too often. To keep the entire train on the tracks you want all the cars to weigh about the same, a light car sandwiched inbetween two heavy cars can get pulled off the track on curves, “stringlining” some call it.
Weight is weight. House cars where the inside is concealed, I will weight with anything lying around the shop, old nuts and bolts, bits of this or that. I use silicone bathtub caulk to stick the weight in place. Where space is limited lead gets you the most weight in the least space. Building supply houses and lumber yards sell sheet lead for roof flashing. It is soft, cuts easily with tin snips or even scissors (your shop scissors, NOT your wife’s good sewing scissors) and fits in a lot of places.
For locomotives, more is better. Pulling power is limited by wheel spin, once the wheels start spinning, the locomotive won’t pull any harder, no matter what. Put more weight in the locomotive and the wheels will pull harder before they spin. In fact, knowing the weight of a locomotive you can figure its max tractive effort (pull power) to be 0.25 * the weight. Want more pull? Give it more weight (or rubber traction tires).
Jim’s point about allowing the wheels to spin is correct. However it isn’t usually a problem in HO. In my experience there just isn’t enough room inside HO locomotives to pack in so much weight as to prevent the wheels for spinning when the locomotive is caught and cannot move.
Back in the ‘old’ days with Athearn BB engines with the ‘sintered’ iron wheels, this could be an issue. The normal ‘out of the box’ weight of these engines would cause the engine ‘hop’ when the sintered iron wheels lost their grip on the rails. Adding weight got rid of that hop, but they would then ‘stall’ and you could burn up that ‘Jet’ motor! The advent of n/s wheels meant we had engines that were ‘slippery’. When the train ‘stalled’, the engines wheels kept turning. Some guys complained that they could not pull as much with the new wheels(can’t satisfy everyone!).
I was an early convert to n/s wheels. I had all of my Athearn engine equipped with either Jay Bee or NWSL n/s wheels. After I saw how well the new Atlas SD24’s performed(both electrical pick-up, and smooth running) - I was a convert.
While it’s possible to load a locomotive with weight, sometimes that leads to some unrealistic results.
To handle most traffic on my coal-originating mountain goat trail with rails on it I have a bunch of teakettle tank locos (0-6-0T mostly, with an 0-8-0T and a 2-6-2T also present - the larger, heavier, higher-drivered JNR 2-6-2T and 2-6-4T are embargoed from the route) which have about as much weight as BIG vertical-shaft motors, lighting diodes and such will allow. My strongest puller is - An 0-4-0T, model of an 1873 prototype!
Why? Because that little Hohenzollern is a solid block of lead, cored out just enough to clear the motor.
So, should I park the pair of 0-6-0’s that usually pull the mixed and substitute Superloco? I don’t think so. I’ve designated it the colliery shifter, where it runs on level track and can’t demonstrate its superior grade-climbing ability. Sort of like making Home Run Harry the bullpen catcher, but that’s my decision.
While a majority of my cars are to NMRA specs, there are many cars that are below. The reason being is that the prototypes have to deal with light(er) cars throughtout the trains, so why not us as well.
This forces the operator to be real careful with starting and stopping the train. I use DCC, and all locos do start at 1 on the throttle setting. I do not have any momentum or deacceleration programmed into any of my locos as I believe that those are “cheats” that give “bad” operators a crutch, instead of making them be real careful with their trains.
I do have realistic speed curves and speed limits programmed in that will give a very realistic start, and top speed appropriate to the engine, when the operator is careful. If the prototype was pretty much limited to around 40mph, I program it as close as possible to that speed. If it ran at 60, thats where its top is sat. I believe that most problems with light cars are do more to how they are handled by the operator, than to their light weight.
To date, there have been zero derailments on the layout caused by stringling due to light cars. The very few derailments that do occur, are generally due to operator error, and not the equipment, and definitely not the weight of said equipment.
I am a fan of Bull Frog Snot. That stuff is wonderful. It has a learning curve to apply it properly, but there are videos on youtube. Once you get one axle on a steamer with that stuff, one you can forego for the sake of pickup, you can almost double your tractive effort. It lasts a fairly long time, too.
For standard gauge cars, I weight to NMRA specs. There’s never a shortage of tractive effort, so a little more than what’s strictly necessary – which is my own evaluation of NMRA weighting – is not a problem.
For HOn3, I usually make them underweight per the NMRA. This is not uncommon for us narrowgaugers. In fact, you’ll find most Blackstone cars are lighter than NMRA. This was a result of discussions with modelers while still in the design process. Narrowgaugers are usually short of tractive effort. My C-19s are good for 3, possibly 4 cars max on my 4%. That’s about prototypical performance, not complaining, but it’s just that the physical mass of the NG locos is substantially less than in SG
What’s critical is relatively even weighting. You won’t miss the extra weight and your trains can be prototypical length. I do have a few cars I built before moving to lower weights. They’re always good for a surprise to the unwary crew[;)]
Then there’s OZ, which is really heavy, like the prototype.
