3 engines up the hill and the wheels are spinning

I ran the first official train up the mainline and back. Up front: 93 Lionel 4-4-2 and 05 Lionel 4-4-2 both of which running off of front engines reverse unit. Both engines with little operating time. 3rd engine Lionel GP9 DM&IR 8158 that has the old big motor under cab and just one driven truck. 9 scale cars behind them and the wheels on the GP9 were spinning easily and one traction tire was loose. I have new traction tires to put on it or else I’d like to glue some on, but with what kind of glue I’m unsure. The 4-4-2 were not spinning. I wired them last winter and forget whether I wired them in series or paralell. I know the GP9 pulls better uphill when faced backwards, maybe I’ll try that. The 14g copper wire along the entire layout seems to be working well as my old MRC 027 transformer didn’t have to be cranked up high to run the train. My calculations could be off and its possible some parts of the main line could be 2.5% or slightly more. I was hoping I could pull 20 car trains up this hill but I’m not sure how I will do that. I also have 2 late 80s or maybe 90s GP20s that are both dual can motors, just gotta install a rebuilt truck. I have an old flatcar that I attached some big motorhome levels to. Now I just have to mark them for degrees of grade. I put white masking tape over the numbers that are on them. Sharpest curves in the climbing section are 048 Fastrack. Here are the fixes I’m thinking of:

  1. Replace traction tire GP9 and turn it around and run long hood foreward.

  2. Rewire both 4-4–2s so they go faster?

  3. Add weight to all 3 engines. In 4-4-2s I’g guess to the cabs and maybe under the cowcatcher or maybe in the pockets where the rods go in and out of? GP9 add in the nose of the cab.

  4. Get the 2 GP20s running and wire them together. Could one reverse unit power 4 can motors?

  5. I don’t have the $$$ to buy a big pulling big $$$ engine and I love to run steam engines. I could even find 1 or 2 more modern Lionel 4-4

I think you are expecting too much from small engines made for sets with three or four cars. Also the grade may be to steep. With what you listed the two GP20s with dual motors would be your best chance, but I would guess you would be overloading the e-units with four motors.

If the individual engines do not run very close to the same speed at a given voltage they are probably hindering rather than helping. In a lash-up all the engines should be geared so that they are operating at similar speeds at a given voltage.

Well the spot where the train stalled is about a 3% grade in the middle of an 048 Fastrack “S” curve. No wonder the wheels were spinning on the GP9. I ran another train with just the 2 Lionel 4-4-2s. Had the old MRC 027 cranked all the way up, they were moving slow and the wheels were not spinning. So whichever way I have them wired, series or paralell, I will be wiring them the other way.

P.S. don’t tell mom I’m changing the route and am going to run a loop into and out of the closet so I can get the climbing grade down to something I can live with and that won’t burn out all the motors.