More Musings

[Mookie]

See-Sawed a lot this weekend! Both days!

Will maybe break this into bits - kind of like - train too long - blocking forum!

Saw one of our SW15's moving a little furniture. If you ever get a chance to listen to one of these - either the 10 or the 15 - it is so mellow. The horn sounds like "a French Horn" according to the driver. It just lopes up and down the track - almost no effort expended.

But brings up question! He pulls a long string of cars out w/o breaking a sweat. But then he has to pu***hem back and you can hear him clear out at our house - sounding really strained. Is it harder to pu***han to pull? Or is it possibly up and down hill?

There's one...

Mook

[Noah Hofrichter]

Mookie, the up and down hill thing makes sense. And the other one does too. I noticed on my models it's much harder to push cars then pull, but I'm not sure about the prototype.

Noah

[Anonymous]

If he is pulling then stops and the slack bunches up, then goes to push it would be much harder to get going again because instead of slowly pulling on car at a time and adding them on, he's pushing all of them, or at least most of them....

Just a thought.

[eolafan]

Mookie, some engineers will switch from forward to reverse just before the energy of the forward motion is completely expended and so they are pushing against that momentum and must "get things back to zero" before they move in the other direction, thus resulting in the "straining" you speak of, all of which I have seen many times while "foaming". Does this make any sense at all to all of you folks?

[Anonymous]

QUOTE: Originally posted by eolafan

Mookie, some engineers will switch from forward to reverse just before the energy of the forward motion is completely expended and so they are pushing against that momentum and must "get things back to zero" before they move in the other direction, thus resulting in the "straining" you speak of, all of which I have seen many times while "foaming". Does this make any sense at all to all of you folks?

Yes it does.

Sounds like doing that would also be pretty hard on the motor itself.

[JoeKoh]

Mookie
csx had a switch in the old neighborhood. could here the engine glide but coming back out would realy strain with the loads.just gravity doing its job.
stay safe
Joe

[kenneo]

It is a little harder to push because there is no slack available to ease the strain, but this should not be a problem unless the cut is at tonnage. Pulling up a grade steep enough to keep the slack streached would do the same.

The engineer can tell when all of the slack has run in when stopping a pull, but the longer the cut, the less he can feel. So he can wait, if he wishes, for all of the slack to run in, but probably won't. The reason is two fold - first, the YM (yardmaster) probably will get on the foremans case about slow switching (and the RFE's (Road Forman of Engines) as well, so the engineer will get a double dose of complaints) and second, there is no real advantage in waiting. By pushing against the cut, the slack runs in quicker and the cut actually will start to move faster sooner with the end result, generally, being easier on the locomotive, and definately making things easier for the YM and the foreman.

And, yes, if the engine is operating at maximum loading, he probably is shoving into a slight grade if he was pulling them out at about half throttle (runs 4,5 or 6) and doesn't ease off the power after he gets the cut moving.

[edblysard]

And, if he does jumps to quick on the reverser, while the whole cut isstill pushing him, he can burn the brushes in the traction motor, big time no no with the RFE...so it takes a little practice.
Timed just right, he can use the que ball effect to his advantage, the slack runs in when he brakes, and then bounces back out, which is when he moves the reverser into the other side, and gets on the throttle.

An experienced yard engineer can play the slack any way you want, and if he's real good, you can get a double tap of of him when your kicking cars.

About the only thing that will make it harder to shove than pull is hand brakes on the rear end, or, as you suggested, shoving up a grade.
The reason its easier to pull the brakes, is because you already have all the weight and mass ahead of the brakes moving, their weight drags the cars following and it works for you, when shoving back against brakes, your pushing all the same mass and weight against the brakes, its harder.


Ed

[tree68]

Could it be that he's just too far away for you to hear him working when he's coming your way, but since he's right there when he heads back towards whence he came, you get the full effect? When he gets to you, he's just coasting, for the most part..

[kenneo]

QUOTE: Originally posted by edblysard

And, if he does jumps to quick on the reverser, while the whole cut isstill pushing him, he can burn the brushes in the traction motor, big time no no with the RFE...so it takes a little practice.
Timed just right, he can use the que ball effect to his advantage,

You are quite correct about jumping on the reverser. Flash overs, flat wheels and gound down tread. All very good reasons for the granting of long unpaid vacations. This manouver must be done correctly and the ping pong usually is used. I have seen yard engineers use this method to send several "sets" back through the cut by using repeated sets and releases so he can use the train to stop itself to the maximum he can. The same can be used when starting as you described.

In referance to my first paragraph, unless the cut is streached tight (or shoved tight), the loads and empties will pig pong off each other a bit and make it easier on the locomotive. Pulling through switches also causes the load to increase on the locomotive.

Neglected the handbrake issue. One simple brake can wreck havock on the engineers best efforts.

[Anonymous]

QUOTE: Originally posted by Mookie



Saw one of our SW15's moving a little furniture. If you ever get a chance to listen to one of these - either the 10 or the 15 - it is so mellow. The horn sounds like "a French Horn" according to the driver. It just lopes up and down the track - almost no effort expended.


Mook

We had some old NW2's and SW1's way back with a single trumpet horn. I used to quill them just right...they'd sound like a love-sick moose! Not pretty-but FUNNY. It sounds like your yard pups are doing some piddlin'; not funny but FUN.