Weighting Locomotives Traction vs. Wear

[brokenrail]

A friend had a layout exactly like that and he ran a 30 car modern coal train the 100 ton type bathtub gondolas and he used metal Kadee couplers and a few some how bent their shanks in the middle.Strange forces at work even scaled down to 1/87.All of has cars were loaded and they all ran metal wheels.I could not see how it would do that, but he used a lot of head end power with no helpers to get through what he called the challenge.
Johnny

[electrical whiz kid]

The 'challenge' being...

Rich C.

[brokenrail]

What force makes the short metal coupling arm bend?Have you ever tried to bend one of these by hand in the middle of the coupler shaft?It can be done with 2 pair of needle nose pliers to a u-shape that we were seeing.Very strange. And the challenge is what force can do this in ho scale? Not just once .The metal was still firm wile bent the way it was where you could not bend it back by hand.
Johnny

[rogertra]

What force makes the short metal coupling arm bend?Have you ever tried to bend one of these by hand in the middle of the coupler shaft?It can be done with 2 pair of needle nose pliers to a u-shape that we were seeing.Very strange. And the challenge is what force can do this in ho scale? Not just once .The metal was still firm wile bent the way it was where you could not bend it back by hand.
Johnny

He used the Force Luke, he used the Force.


Cheers

Roger T.

[brokenrail]

 

[electrical whiz kid]

REF:  "Please Mr. Spaceman" by the Byrds...   As in Roger McGuinn

One area I have seen a lot is skewed track-work.  Once you lift one side of a truck, frame, etc, off of the rail, you are putting your consist in a potentially bad position.  Be totally fussy about this area.  put a level across the rails, make sure that the bubble is consistent with relation to the run.  Straight runs are usually the culprit, as your guard is down when laying straight track.  If you check the track this way, and find a lot of axial twisting, you are asking for trouble.  Make sure that, as well as good joints, that the track is consistently smooth and straight.  Curves are another area to watch in this manner.

Rich C.

[jward]

rich, this is one reason I am against superelevation on curves. if you spend a lot of time shimming and eliminating the twists in your trackwork, why would you want to purposely introduce more of them?

at least with ready made track you can use index cards to level things out. with handlaid track like I build, levelling means cutting out the ties on the high side to lower the offending rail.

[electrical whiz kid]

Jeffery;
Super-elevation is a matter of taste and preference.  If you are modelling 'Horse shoe bend', you will almost have to super-elevate for it to at least look good. On my layout, that kind of stuff needn't be.  Twisted, skewed, and kinked track-should be really gone after with a magnifying glass-and be fussy..  When I built my HOn3 layout, the track writhed and twirled like a python killing a jackass to eat it.  HOn3!!  Talk about begging for trouble...  I learned the hard way on that layout, and now, as I build this layout, I try to be as 'nit-picky/fussy' as I can with said track-work. This means a level, a straight-edge, and a laser light on the end of a torpedo level (newer ones).  This all works great; so if the guys and gals go the extra mile, it will pay off in big dividends.

RIch C. 

[rogertra]

rich, this is one reason I am against superelevation on curves. if you spend a lot of time shimming and eliminating the twists in your trackwork, why would you want to purposely introduce more of them?

at least with ready made track you can use index cards to level things out. with handlaid track like I build, levelling means cutting out the ties on the high side to lower the offending rail.

On my old GER, where all visible track was hand laid, I simply tilted the road bed inward a few degrees to give the illusion of superelevation.   On the new GER, using flex track, I glue a strip of suitable size balsa under where the outside edge of the ties will be, pin the track down using temporary push pins and then ballast and glue.  Bingo, superelevated curves.

Cheers


Roger T.

[brokenrail]

Tried the super elevating thing by the book and it caused more problems .Ended up removing it all.Seems to cause derailments more so then good level curves when doing a push and pull. In my opinion a push and pull in either direction is a good way to weed out track and or rolling stock issues. What does super elevation have to do with weighting locos and or rolling stock.Maybe I probably missed something?
Johnny

[jward]

superelevation can in some cases cause poor contact between the wheels and the electrical pickups on a locomotive, as the locomotive's center of gravity shifts as it leans into the curve.

[rogertra]

superelevation can in some cases cause poor contact between the wheels and the electrical pickups on a locomotive, as the locomotive's center of gravity shifts as it leans into the curve.

Max superelevation I use is about 1/16",  or the metric equivalent.  That's less than prototypes maximum superelevation of around 6" IIRC.  I only superelevate my visible mainline track, 36" radius minimum curves.  My passing sidings, yard and industrial trackage, like the prototype is not superelevated and thus speed limits apply.   If your locos are losing contact on your superelevated curves, that suggests your superelevation is too much and or the curves are too tight.  I'd suggest not superelevating curves under 30" radius.

Cheers.


Roger T.

[brokenrail]

What does super elevation have to do with weight and traction?
Anybody have a theory about center of gravity? .Obviously it is important in the kettles along with balance for and aft.Think about diesel models.Will they pull better with the center of gravity low to the rail ,like in the fuel tank and metal trucks like Bachmann uses in their Spectrum 6 axle diesels?
Opinions?
Johnny

[electrical whiz kid]

Johnny;
Wouldn't you say that, as a rule, the lower the weight sits (COG), the more stable things will generally be?  I believe that, if we could keep weight positioned as low as possible, that things would be better.  Once you start varying the motion with mass/centrifugal force,  so results start as well. 
Curves are a necessity in most cases, for model railroad operation; and as such, will need some form of consideration(s) to be observed.  Variables would be  speed(motion as centrifugal force), weight, balance, radii.
Without going into a lot of mathematical hocus-pocus, keeping more weight in the locomotive-and down low- than in the load; would make things generally run better through variations of track.
Now, you must also consider your radii with speed.  Otherwise, "string-lining" will occur, as the loco tries to overcome resistance via the "straight-line" theory.  Think of it this way: if you tie a weight on a string, and tack the other end to a hanging set up, the string will conform to the demands placed upon it by nature and hang straight.  This applies to your curve, train, COG, etc.  The more weight imposed upon the loco by the load (train), the greater the tendency to "straighten" the train out.  In our case, this might result in the need to "MU" locomotives; weight as well as power.

Rich C.

[brokenrail]

Well put man Thanks!