All my locos are 3 pole motors. They all run at the same speed, not that I have ever noticed any difference.

Can't speak about steam, as I avoided buying them due to traction issues in Z, only have two of them.

4 axle diesel & electric, bigger/heavier ones are the best to start will, or you will get frustrated. Then 6 axle (the centre axle of each bogie is about 0.5mm raised, so traction & electrical they are in effect only 4 axles), often they don't run just quite as well as 4 axle. Last the smaller locos. Then steam after that!

Multiples of the same loco definitely run at the same speed. Something I have noticed when I haven't purposely linked the couplings.

Wheel spin.

From my experience wheel spin is not an issue other than wearing off the chrome plating, abate very slowly, & I have flogged my ICE locos to death.

A few of my locos I have modified (machining in grooves) adding traction tyres. Even those locos still spin the wheels if the train set is too long.

Z locos just don't have anywhere near enough mass to stall the engine. Even adding lead to an ICE to over 50 grams & traction tyres on the third axle (best downward force) on the leading loco only (rear loco was not necessary) doesn't cause any issues.

I have put a set for traction tyres on the rear ICE loco, swapped an axle with another loco. But thought it wasn't necessary for the second loco to have traction tyres on a long ICE.

Rear loco did have extra weight, but not quite as much as the leading loco.





ICE.mov (2,462kb) downloaded 149 time(s).





Bypassing diodes on the ICE is the first most worthwhile modification so each loco picks up its own power, rather than the leading loco to then power the rear loco.

Tyres are heatshrink tube, not heated, simply stretched over the rim. The tyres have lasted brilliantly.

The key is, make sure the engines came from at least a same batch of production. Like what I experimented with mine here, ?si=rZ4VLrri9z_1UzOE
note: full analog on my layout.

For the steam, AFAIK, it's also the same.
As in my case, I have two big steam engines, the S3/6 and the BR41. I replaced the S3/6 motor with 5-pole, less torque but slightly smoother than the BR41 (original 3-pole motor, better torque). I found it not ideal to use them in tandem due to difference in speed and torque.

Hi
I was surprised that those two engines had the "grunt" to pull that long train.
With that kind of torque, it seems to me that maybe the 2 percent rule on grades might not be quite accurate using similar engines.
Regards,