I don’t know if this is the right place to ask this question, but I saw no other area specific to locos.
I have 2 locos, a PA-PB and a GP38-2. My grade is no more than 3% in some places, and 0 in others. I have 8-12’ curves. I will be powering with battery. My question is; what is the limitation of the # of cars I can pull behind each loco.
Traction tires will help a lot, make sure they are in good shape.
(no more than 3%? wow)
Have you decided how fast you want to go? (voltage on batteries)
8’ curves on a grade will be very different than 12’ curves on a grade.
I’d expect maybe 8 cars max on the GP38, and maybe 12 on the PA-PB combination.
With that type of grade, the type of rail also comes into play, Aluminum will give you the most traction, brass a little less, and SS can be very slippery.
Remember that the weakness in USAT locos is the “cracked axle” syndrome, and keeping the traction tires on and steep grades is a sure way to experience this… they can be repaired and made bulletproof, but you better do this up front.
I’ve got a section on this on my site… in the search box, enter “usat split axle” and hit enter, it will be about the 6th hit… (it’s mentioned in several places on my site)
Regards, Greg
Greg,
Thanks for the quick reply.
How fast - well looking for the PA-PBs to be the faster of the 2. I am having battery installed professionally, so don’t know what they will set it at.
I have brass rail.
I will be heading over to your site to read about teh “crfacked axle” syndrome tonight when I get home.
I was thinking that a 3% grade is not all that much, correct? OI figured that the GP 38 will run on the inside 8’ curves and the Pa-PBs will be on the outside curves which are about 10-12’ radius’.
8 cars on the Penn GP38 is all that I’m looking for, eventually I will run the passenger cars on the Pa-Pb, but not until I can expand and make a long run down both sides of my yard, with 12-15’ curves. Right now the New Haven Pa-Pb’s will be pulling about 6 cars.
You say you are having the locos “Converted proffessionaly” to Battery…then you state: as far as speed is concerned; "…don’t know what (Speed) they will be set at…
I do hope you realilize that grades cause the locos to increase and decrease in speed, and should have some sort of control system; not just batteries…
Battery power is the ideal way to go, for the least maintenance (Some will disagree for various reasons), but it requires some sort of control system. If the “Proffessional installer” hasn’t suggested this to you; you might be wise to look for a more knowledgeable person to do the installation.
Shelly, Here is a pic of 2 Geep 38’s on a 1% grade pulling a 50+ foot long train…the garden posts are spaced 8’ o/c …it’s about 17 cars I believe…no issues what so ever but I have broken couplers in the past.
(http://i45.photobucket.com/albums/f72/Shortybear/ECLSTS/RydersShots087.jpg)
Grades are tricky, I have 3 locos that pull a 3.5% grade, and they are just on the verge of wheelslip with 50 40’ freight cars, these are Aristo E8’s with 6 additional pounds of lead each.
I have 5 USAT PA’s, and a couple of GP’s too… they are not weighted as much as Aristo’s and don’t pull as much.
Grades are weird… what you can pull diminishes rapidly as you increase the grade… 1% is pretty much not much trouble, 2% is stiff, 3% is just plain steep.
On one place in my layout, I have a 5% downgrade, and a friend brought an Aristo SD45 that would pull tons of cars on the flat… It managed 6 or 7 cars up the 5% grade.
One thing you want to avoid is running them so hard you are close to the limit, because you will get rapid gear wear if nothing else.
It’s really hard to estimate.
My question about speed was more along the lines of what voltage batteries you were going to use, like if you really wanted to be able to achieve passenger train speeds. More curiosity than anything else, but the volume of batteries depends on both the amp hours and the voltage.
Let your brass rail oxidize, that will increase traction… only “clean” it of twigs, and sap, etc…
Regards, Greg
Fred,
I am having battery installed and the control system being installed is an Aristocraft TE with Phoenix sound. I don’t have them yet; I can’t wait to start running them, but the GP won’t be in my hands until Monday of next week and the PA/PB hopefully by the end of the week!!!
Boy you guys run long trains!!! How fun. I am just hoping to be able to pull 5 or 6 cars behind the locos. I guess with regards to the grades, curves and rolling stock, I will just have to experiment, without hopefully doing any harm to my engines. 
5 or 6 will be fine. When you asked for the limitation, I was afraid you wanted 20-30 cars…
If you did not have the traction tires, I would recommend adding cars until you got wheelslip, and then back off 3-4 cars for your max.
With the traction tires, my opinion is that kind of test puts undue strain on the drivetrain.
Regards, Greg
Greg
No I don’t have traction tires, but I like the idea of testing the limits by adding cars, Awesome, thanks for the suggestion.
Shelley, I made the assumption that your PA-PB are usa trains… if so, they should come stock with traction tires… although the new ones might not…
Every one I have did, but I swapped them for non-traction tired ones and removed the sliders too (I’m track power).
I’m not sure on the GP38-2, I thought it came with traction tires, but recent locos from USAT do not.
Have you looked? (no offense meant, just it’s not always obvious)
Regards, Greg
shelley sherbondy said:Just ignore me Shelly I'm in my own world and also running track power that I'm quite happy with. Only sharing ;)
Boy you guys run long trains!!! How fun. I am just hoping to be able to pull 5 or 6 cars behind the locos. I guess with regards to the grades, curves and rolling stock, I will just have to experiment, without hopefully doing any harm to my engines. :)