the two most effective things to "make trains long(er)" are 1. reducing weight per car and 2. improving their rolling ability.
Regarding 1. This of course has directly to do with the used curve radii. I am assuming a person being a member of a group interested to create freight cars as accurate as possible won't use ridiculous radii to run these cars.
Many - including me - think that the NMRA recommendations for car weighting are outdated. Many think it isn't necessary to make cars as heavy as per those recommendations dating back to trucks with awful rolling quality and track systems and laying procedures remembering more to toys than to 'serious modeling'. Much more important than high total weight is an as low as possible center of gravity - which you will automatically get by using all-metal wheels and metal couplers. Within my "non-brass-days" I used to run trains of much more than 100 cars with only one engine - the cars all being plastic kits built without their steel weights. Admittedly on curves no less than 80" - but it worked PERFECTLY! - not one single derailment. I am very sure (and several of my friends already tested it and confirmed to me) that it will work as fine on much tighter curves as long as you have fine and smooth track everywhere. During the coming years(s) I will test it with a 100 car C&O coal train (Atlas, Accurail, etc.).
Regarding 2. Todays plastic trucks usually have fantastic free-rolling quality - and I recommend to use those and convert every car to current trucks as long as the accurate type is available. By doing that I also use a spring under the scew head - tight enough to prevent wobbling/ jiggling and soft enough to allow free movement of the truck.
The following link does show my current freight train, engine seen is a brass Challenger Imports DM&IR 2-10-4:
Engine (without tender) weighs about 21-22 ounces.
Fact 1: -all cars are BRASS! I didn't check total weight, but it's really heavy...
Fact 2: -most cars have been converted to Tahoe (and a few other) plastic trucks, but about 10 cars still have their original brass trucks, and 4 or 5 of them are rolling really bad.
So I don't have any doubts that this engine is able to pull maybe 70 brass freight cars when equipped with good trucks and 100+ car plastic trains with current (great) rolling ability.
As another member already pointed out, the earlier Japanese models usually are much more rugged, heavier and long-lasting than later Korean models (but are less detailed in most cases).
Regarding your engines: -make sure the mechanism is running well without any bind at any place at your layout. Check this by removing the gear box and shove engine by hand. Make sure it tracks well, has a good gear box and a strong motor of course. Make sure the center of gravity is above center driver, add some weight when there is room. (But don't overdo this - the motor should be strong enough to turn drivers by about half-throttle or even a little less - if it stalls it won't live long...). Pilot and/ or trailing trucks should have A LITTLE spring pressure to hold the truck down on the rails - but very often it's way too much - robbing a lot of pulling power.
I hope this is of some use for you. Good luck and happy modeling!
Samstag, 21. Mai 2022 um 11:17 Uhr
"nyc3001 ." <nyc3001@...
Re: [RealSTMFC] Brass Steam Locomotives that Pull Freight Cars.
The only one I'm aware of is the Brass Collectors and Operators group.
Personally, I'd be interested in a group discussing methods to make brass steam locomotives pull prototypical-length freight trains. It would be cool to see a single HO 4-8-2 (for example) pulling 70 or more cars on the level at track speed.