Oh, okay. I guess I could just go with two AC6000CWs. It's only money, right?
Unfortunately I don't have $300 at the moment. The other thing I am finding is that my RR is really susceptible to start and stop operation. It seems that the tracks and wheels get dirty really quickly. I didn't realize there would be this much maintenance. Sometimes my train stutters even with things being clean. I was hoping that with two locos that if one hit a dirty patch the other loco would pull or push it a bit so it wouldn't be an issue. I'm finding however that one loco can't pull the train by itself so this doesn't work like I was hoping. That's the other reason I was thinking of going with two stronger locos so that maybe I could leave my training going slow in the background without it stopping while also not having to clean the tracks as often as I am. I'm curious how often other people clean their tracks.
The number of wheels on the model is somewhat irrelevant , draw bar pull is determined by locomotive weight and the coefficient of friction between the wheel and the rails (around .2) , the one thing you do get with 6 axle is more consistent traction , and 6 axle locomotives tend to be heavier . I have known people who were somewhat disappointed when their Blu Box SD40s didn't pull significantly than their Blu Box GP38s , and the 38s tracked better because of the shorter wheelbase. The SDs had a little more pull but their dummys were heavier so the net effect was a wash.
On the prototype ,things are a little different .Things like sand , active traction control , traction motor heat build up, weight distibution and other factors , come into play , that make 6 axle more desirable ( 4 axle are for the most part gone ).
From a modeling perspective , 4 axle is more forgiving of track issues.
Bottom line is if you want to pull more cars , you either
(a)lighten the cars
(b) use a heavier locomotive ( either purchase or add weight)
(c) reduce the grade 2% is usually about the max (2" for every 100")
or (d) all of the above.
If your having trouble with stalling you might want to start another thread , we need to know things like type of track , locomotive type ,pics help. Several issues can cause stalling.