Lashup engine speeds

I have over 13 MUs and double and triple headers and I have only had an issue with one (Alco S2 and V1000 both Rdg). While the MTH engines do not run at the same speed only that combination had too great a difference in smph.  I run the fastest in the lead and follow each with a succession of slower engines. Most of my MTH engines (PS2/3) are within a smph of each other.  I even use this with trains having my fastest train first on a loop followed by a succession of trains that are a little slower than the one in front and started with the "all" command for each loop. I have not had any issues with the Legacy engines and they seem to all run within 3 speed steps at 10 smph (37-39). Note on Legacy the same speed (smph), the speed step will be different for a road engine, switcher engine and subway.

It's an interesting exercise, and we did this for our 115 car consist that I posted.  We were originally trying to run four Legacy engines pulling around 100 cars, but they kept pulling the consist apart.  I tried my U-Boats and ran them around a few laps separated by a foot, they were very consistent pacing each other.  As it turned out, they worked well for the consist as well.

For Legacy or DCS, it's easy to test speeds.  You can space the engines you want to test out and use the ALL command to run them all at the same speed around and see if the speeds are matched.

If I set something up and it acts funny, I usually check to make sure no engine "runs away" from the rest. The tach reader has a tolerance, its not super tight, so if you get one on the high end of the range and another on the low end of the range, the speed differential can be somewhat substantial. The bigger problem seems to be between generations of the electronics. In my experience, 5V PS2 runs faster than 3V at a given speed, and PS3 runs a little bit slower than PS2 does. It could be calibrations, it could just be the electronics getting better at reading. If the train is really heavy, and you have a speed differential, you end up with one engine doing all the pulling work, as well as trying to shove the engines in front of it, and that combination can lead to some hot boards. So its best to put the fastest runner in the front of the MU. You will find the occasional engine that just wont play nicely with others, but I would say 90%+ of the 20 or so MTH engines will play along fairly well with one another.

Okay, now I have to put this out and ask.  I have 3 K-Line TMCC equipped locomotives, a GG1, A Big Boy, and an Allegheny, and my son has one Lionel, the HHP-8.  So I decided to go ahead and take the plunge and I got a used TMCC command set with extra Cab-1.  Once I got the base tuned back to frequency, we had fun running our locomotives with the Cab-1s, but the CW-80 just wasn't cutting it power wise, so I got a ZW-C.  Of course with all the power, we wanted to see how long a train we could pull.  We put all our freight and passenger cars on the track and tried pulling it.  Of course with mostly O36 curves we were clotheslining. So I decide to add a helper.  Of the 4, the GG1 and the HHP-8 ran great together.

But here is the thing, If I put the BB and Allegheny on the track with a space between them and addressed them individually, they ran at the same speed.  If I put them in a lashup, whichever locomotive was the lead now ran slower when going forward.  When the Allegheny was the lead and I put the train in reverse, it would run faster than the BB.  But when the BB was the lead, it always ran slower, no matter the direction.  Neither has cruse, so that wasn't a problem

So why do they run fine when addressed separate, but in a lashup they run at different speeds?

I can't really answer why they don't run the same speed in the MU configuration.  I don't try to run TMCC stuff in an MU configuration as there are too many speed issues between different models.  Legacy and PS2/3 stuff runs great in an MU for the most part.

I do know with two Lionel Legacy U28C locomotives you can run 115 cars on O72 curves.

The TMCC stuff gives me the most trouble. I have an ABBA set of TMCC Lionel F3s and F7s. Each consist has a powered A and a powered B unit.

The F3's will not play nice together.

The F7's run perfectly together, forward, but not so well in reverse.

On another note, my new Sunset FP7's are an exact match forward or reverse. ERR boards I believe. They run perfectly together whether I make them "TR" or call both engines "ENG 1".

The ERR stuff has a "nudge" feature to match speeds, so it's a lot easier to get those to run in pairs.

I have a permanent doubleheader of two 4-4-2 starter set steam locomotives on my layout. An NKP in the lead, and an NYC that I modified by cutting the pilot off a spare shell and bolting a coupler to the lead truck.  Conventional control.

Separately, they either knock each other off the track or run away from each other.

Coupled together they run perfectly forward and reverse. The hard part is keeping the E-units synchronized especially when I'm not operating the controls.

Someday maybe MTH will have PS4 with TIU release 5 wherein you fine tune each loco speed and other parameters much like DCC with their CV modifications.

So how do the real RR engines compensate for variations especially where you have mixed loco consist say road engines and switchers together with different gearing, primemover horsepower, generator/alternator voltages etc. 

I recall a thread long ago where the poster likened the consists to  tug of war team each member contributing their strength regarless of musclel, size, age etc.  I would assume this analogy would hold when the engineer shoves the lever to run 8, each engine does the "I think I can, I think I can" (sorry couldn't resist the silly here, late in day) mantra on their drawbars.

Well, in theory, MTH locomotives all run at the same scale MPH, at least the factory equipped ones are supposed to.  So, you should be able to line up a number of MTH locomotives and run them all around spaced out with the ALL Engines command and have them maintain the spacing.  Obviously, it won't be perfect, but it should be fairly close.

Good afternoon

I run two to four separate MTH trains on one loop, some lash ups some single, some heavy loads, some light. It all works good, If I find one slower than the others it is usually because it has a harder pull in which case that gets a lash up also. I really like the all button.

Clem

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