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The absolute power in kilowatts x 10^-n delivered to the drawbar seems to be an elusive answer, given the many variables: Voltage, track and wheel cleanliness, humidity, temperature, phase of the moon, mother's blood type, etc.

It’s not elusive at all.  If you truly want “power” in the engineering textbook sense, just measure the pulling force over some distance and time.  That’s all a horsepower is.  I think it’s defined by lifting 33,600 lbs 1 foot in 1 minute or something.

You guys are mixing up force and power engineering units of measure. It’s a little upsetting to me as a professional calibrator.

You will also need to measure distance and time to complete the power calculation.  P=(FD)/T

Be sure to take a few runs at the measurement, discard the data, reset the load measuring device to zero force, then record last run. This will remove hysteresis from the load train and the sensor/scale.

Seriously, thank you for the knowledge-based feedback with a formula-- great!

And, if you're the same Norm that is able to take a drive bisecting Detroit's 'burbs in order to walk-into P&D Hobby rather than pay shipping charges-- I'm feeling, "Wish I could do that!" This is especially true due to having been raised in Detroit and having been able to combine a trip to P&D with my commute to Metro Beach where I Life Guarded "100 years ago."

@Mannyrock posted:


I have read alot of posts on this board over the past year, and many of them discuss problems with, or no problems with, the pulling power of locomotives.

Is there a standard way measure the actual "pulling power" of a locomotive?  Seems like there should be.

A simple spring loaded gauge, measuring "pull" in fractions of ounces,  would seem to be in order.   Hook the gauge to the back of your locomotive, hold the gauge in one place, turn the locomotive on full power, and see how far it moves the gauge until it spins or stalls.

(A simple device like this is available for measuring the weight of "trigger pull" for firearms, but it is generally gauged in quarter of a pound marks, from 1 pound up to 8 or 9 pounds.  It tell how much weight must be applied to a trigger before the gun fires, i.e. lets the firing pin go.)


At what point will the coupler fail?

We need to get you on the show with it. The PE Berk put up a pretty big number. 😂

If you remember the previous testing with Richard's track pulling power rig, my VL-BB chalked up right at 7 pounds of pulling power and was the pulling champ for any single engine.  I think I can whip the 40oz pull of the PE Berk!

@richs09 posted:

John - nice video - looks like your layout is up and running.  Nice display of power - of course, those are all empties, right ...

Empties?  Not a chance, this was a revenue freight!

@richs09 posted:

Now about that smoking tanker in the middle of your consist - aren't you worried that some 1:48 scale FRA inspector is gonna come banging on your door worried about the emissions and/or whether its gonna blow??

That's a LOX car, it has to have venting or it would blow.   The "venting" is pure oxygen, at least in the real world.

Now, if I had turned on the smoke on the MegaSteam car, that would be different...

John you got me by 14 cars but I was using two Diesels. Your train looked fantastic. I am a sucker for long trains. Have you ever tried DPU in the middle that is powered? I did once and it was great till the middle unit lost poser on a bridge and the train straight lined! Interesting topic this pulling power!

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