At lower speeds, the GP40 and GP38-2 should pull about the same, figuring they weigh about the same. There is only so much tractive effort available with 4 powered axles. If you try to pull too much, the wheels should slip. At lower speeds, the GP40 should limit itself to 2200 hp or so, to avoid traction motor burnout.
Above 15-20 mph the GP40 will pull the train faster. That is when you go from the tractive effort limited part of the curve to the horsepower limited part.
A SD40 would be roughly 1.5 GP38s in pulling power, 2 more powered axles. But at higher speeds, the GP40 and SD40 should move the train at the same speed.
Mike WSOR engineer | HO scale since 1988 | Visit our club www.WCGandyDancers.com
NittanyLion Yes, just go to sleep. The only thing that scales is the physical volume that the object takes up. An HO scale GP38-2 doesn't weight a ton and a half, does it? That's 1/87th of the weight of a real one.
Yes, just go to sleep.
The only thing that scales is the physical volume that the object takes up. An HO scale GP38-2 doesn't weight a ton and a half, does it? That's 1/87th of the weight of a real one.
tomikawaTT Au contraire, I took 3 years of high school physics, plus biology, chemistry and a hatful of math - not unusual for the Bronx High School of Science. Then, two years later, I aced my one semester naval architecture course. My major was Marine Engineering, which is almost entirely physics and math. (My actual major was named Lynn, which is why I'm a retired sergeant, not a retired admiral.)
Au contraire, I took 3 years of high school physics, plus biology, chemistry and a hatful of math - not unusual for the Bronx High School of Science. Then, two years later, I aced my one semester naval architecture course. My major was Marine Engineering, which is almost entirely physics and math.
(My actual major was named Lynn, which is why I'm a retired sergeant, not a retired admiral.)
Sorry to interrupt, but that's just funny!
Chris Ballinger
Modeling the Clementon Branch of the Pennsylvania-Reading Seashore Lines in HO scale
It is possible to get our locomotives to pull prototype length trains. Several things can be done to increase the performance of each locomotive that generally are easy and cheap if one bought good quality locomotives in the first place and they have no major defects like cracked gears for example.
First thing I do is open up the locomotives and clean and lube the mechanism. Many have lumps of dried grease in them. If the engine has contact wipers I clean those with Atlas conducta lube, generally a drop and a q-tip will do, make sure you leave no fibers on the wiper or mechanism. I use a tiny amount of labelle grease with pft on the gears. Then I reassemble the locomotive.
I do the same for steam locomotives. I have a video on this web site of a 105 car coal train runing up a curving grade that is close to 3%. It is being moved by a pair of 2-6-6-6 locomotives one pushing one pulling. The locomotives are consisted and I ran them for over 4 hours that way with the train orbiting our club layout.
I have also run longer trains if you go to my Youtube site you can watch a 160 car train roll by that transversed the same layout and went up and down the same grades. I have run longer trains.
My goal was to run prototype length trains. C&O ran 160 car coal trains with a single 2-6-6-6 or 2-10-4 over the lines in OHIO. My clubs grades are steeper so I will have to do so with more power. Three diesels were able to pull the 160 car train and have pulled more although I do not have video of any greater than 160 cars. All my cars are heavier than the nmra standard, have metal wheels, and have had the trucks tuned with a truck tuner when needed so they run very freely.
A very small amount of work produces really great results, you can see for yourself.