Question for engineers

This is a hypothetical.

Say I blindfold you, and make you wear earplugs that are 100% effective in blocking all sound. Then I lead you aboard a relatively modern freight engine. Let’s say I’m the RFE. I get you seated and make sure you are well-acquainted with the controls (which in reality, you probably already could use blindfolded!). Then, promising, and swearing to God, and recording a statement that you will be held harmless for anything and everything, I agree to be your eyes and ears.

We head off down the section of CSX in WV where Amtrak’s Cardinal runs. We run for at least an hour, we go as fast as the rules permit; and observe all restrictions, as relayed by me.

Can you tell whether you are running a 4-axle or a 6-axle unit?

Not a engineer!

Presuming the engine being operated is among those that the engineer has routinely operated through the course of their career and the engineer knows the consist of the train being handled.

I suspect the engineer could not only tell whether it is a 4 or 6 axle, but in all likelyhood give you the number of the engine being operated.

Okay, a Rule Amendment: the engineer has never been on this engine, or even one of that model. And he’s never run that stretch of track.

Carry on.

You may have to make further Rule Amendments: there may be ride-quality issues associated with particular six-wheel vs. four-wheel trucks, or noises on curves associated with lateral accommodation.

What aspect of 4-wheel vs 6-wheel operation are you concerned with?

And while I grant you it’s like an extreme case of piloting an unqualified engineer … would someone really trust running only via relayed instructions from a RFE? Pinball might be easier (at least if you were a disciple…)

Then he is not qualified to be behind the controls, as we know you are not a qualified engineer to be acting as a ‘pilot’.

I was mainly wondering about the ride qualities, and whether it would be distinguishable. Like around curves, does one feel smoother than the other. Does one maybe lurch or “hunt” more than the other. Remember he’s blind and deaf too; I could certainly believe that on curves they might sound different. But feel is what I’m curious about.

As a non-railroader I might offer a couple of suggestions (guesses?): I’m wondering if the ride might be noticeably smoother on six axles since any irregularities would be equalized across three axles instead of two? Also, the jolts felt when hitting a joint or a frog would come in evenly spaced groups of two or three. This I’d normally think of as sounds, but it could also be felt.

Would starting a train with a 4 axel loco might cause a more likely hood of wheel slip.?

Hey, it just occurred to me-- if he’s got 100% effective earplugs, how are you going relay instructions to him? Yeah, I know, this all a purely hypothetical case. Let’s put him in perfect noise-excluding headphones, and you use a microphone. But then, if you’re riding in the cab, the sounds in the cab will be picked up. Now let’s have you use the radio to dictate instructions to someone at a remote location who then relays the instructions to our engineer.

Sorry about all this. I need sleep.

I guess I won’t be designing experiments in my next life …

Anyway, I’ll go with with Paul’s super headphones plus the relay.

You still haven’t told us the hypothesis, without which much of this discussion can be little better than speculative dithering.

What about the difference between 4 and 6 axle units is this experiment intended to demonstrate?

I believe that when the OP asked for “engineers”, he meant locomotive, and all that have answered are the other type.

Is the engineer named Tommy?

Yes, I meant locomotive engineers. I was just curious about whether the “feel” of operating a 4-axle engine was significantly different enough from that of a 6-axle engine that an engineer would be able to tell the difference on feel alone.

Since it’s a hypothetical situation, it doesn’t have to meet the operating rules, and I don’t have to be an actual RFE or whatever. It’s not about rules, it’s about the feel of operating different engines.

There is no science or engineering involved.

He/she very well could be.

Do you mind if I get back to you later about the probability?

I see what you did there…

I must be getting old, though, because it took me awhile and they’re my favorite band.

Not me! He made it clear in the initial post that the person doing the ‘Link trainer’ hooding and subsequently giving the vocal pilot instructions was the “RFE” and this made it clear that trainmen, not designers, were the object of the exercise.

There have been designers over the years who were also enginemen – Robin Riddles being the first that comes to mind – but a design engineer would be much more likely to indicate a way he or she wanted the train to be operated, and then concentrate on observations or instrument readings without foreground attention being occupied by running the train safely, etc.

Dave Goding will be a positive authority on riding quality and ‘handling’ here, as he’s done it successfully as a career. I would point out, just to start the discussion ball rolling, that there was a perceived difference in lateral compliance between EMDs with Flexicoil C trucks and those equipped with swing-hanger B trucks.

You evidently didn’t read my post Saturday at 6:39 all the way through. I’m not gonna take it! The RFE figure is the one that would be Tommy; we’re near the end of the opera, figuratively…

Have you given up on getting an answer yet, L.O.?

Is there a noticeable difference in the ride of a four-axle locomotive and that of a six-axle locomotive?

Yes it must have entered my sub-conscious. That did set my playlist for Sunday’s yardwork.
Would be interesting to see a similar test with a “new” similar 4 axle unit (GP/SD40). Maybe this could be done at TTCI in Pueblo.