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thickness of railroad ties

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thickness of railroad ties
Posted by HOnewcomerJ on Sunday, December 9, 2018 6:13 PM

I am new to this model railroading.  Hoping to start building a small, and experimental rr soon.  My concern is the thickness, and lack there of, of H O railroad ties.  (And i have a reason for asking). Real rr ties are square, about 8"x8".  The ties on manufacured track are not as thick as they are wide. I pressume the reason is that originally track was just installed on cork roadbed, which was meant to look like real roadbed.  I guess the cork was supposed to look like a ballasted roadbed.  Since in real railroads, the stone is piled up, not just under the ties, but also partly inbetween the ties, that makes part of the thickness, or the height of the ties invisible.  Hence, model rr track that has thin ties, (not square), is ready to look good on cork roadbed.  But now, years later, modelers are adding ballasting material to their railroads, AFTER installing the track, building it up inbetween the ties. This makes the top of the ties about level with the balasting "stones".  So my first questions is, why haven't modellers insisted that manufactures make the ties square, so the end result would be realistic? About 1/2 the thickness of the ties would be buried in their ballasting and 1/2 would still be visible above the ballasting.  (I suppose the ony way to get that effect would be to ballast first and then install track on top of the ballasting.  That's never going to work!  The track will never lay level so trains can run smoothly on it).  The second question; my reason for asking is this.  When track is to be installed ON steel beams of some kind, in bridges, and on over-passes on black steel girders, there is no ballasting.  The ends of the ties is totally vissible.  Thin ties will look inadequate to hold the weight of a train.  Real ties are fully 8"X8", and that is clearly visible.  Does anyone model that?  How is it done?  I hope that laying my own track with rail and square ties and spikes is not the answer.  I have some patience, but not enough for that chore.  And then i wouldn't know how to attatch the track to the steel bridge parts anyway.

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Posted by 7j43k on Sunday, December 9, 2018 6:28 PM

Real railroad track is ideally supposed to have the sides and ends of the ties buried in ballast.  That is how the ties and the track are kept from sliding around.  It proves tolerable to have the ballast a bit lower.  But, after too much "ballast lowering", there will be problems.

You CAN model track with full ties:  You use wood ones, and spike your own.

 

 

Ed

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Posted by selector on Sunday, December 9, 2018 6:52 PM

HOnewcomerJ

...  The ties on manufacured track are not as thick as they are wide. I pressume the reason is that originally track was just installed on cork roadbed, which was meant to look like real roadbed.  I guess the cork was supposed to look like a ballasted roadbed. 

Not so.  The cork is meant to be the roadbed, not the ballast.  If people want their tracks to look realistic, they do ballast with suitable grains of something, grooming them to come up to about the tops of the ties, just like in the real thing.  So, there's no need to have thicker, and more costly, ties since we'd also have to pour more (costly) ballast to cover them to the 'correct' scale depth.  Wth even more glue.

HOnewcomerJ

.. The second question; my reason for asking is this.  When track is to be installed ON steel beams of some kind, in bridges, and on over-passes on black steel girders, there is no ballasting.  The ends of the ties is totally vissible.  Thin ties will look inadequate to hold the weight of a train.  Real ties are fully 8"X8", and that is clearly visible.  Does anyone model that?  How is it done?  I hope that laying my own track with rail and square ties and spikes is not the answer.  I have some patience, but not enough for that chore.  And then i wouldn't know how to attatch the track to the steel bridge parts anyway.

 

Not so.  Some bridge decks are ballasted.  The beams you mention, on which the ties rest, are properly called 'stringers'. On some decks the ties are merely bolted into place with, as you have observed, the tie ends flapping out in the breeze.

Micro Engineering, I believe, makes 'bridge' tracks with close-set ties.

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Posted by HOnewcomerJ on Sunday, December 9, 2018 8:06 PM
Thank you for your help. This "new-comer" appreciates it.
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Posted by HOnewcomerJ on Sunday, December 9, 2018 8:07 PM
Thankyou for your help. This "new-comer" appreciates it.
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Posted by cx500 on Sunday, December 9, 2018 9:32 PM

Actually, real ties are not square, but rectangular.  I think (memory is starting to fade a little in retirement) main line ties are 7"x9".  Head blocks (the long ties at a switch stand) were 8"x10".  That was for CPR but I imagine it is fairly typical of North American practice.  Slightly smaller ties might be used for spur tracks.

John

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Posted by 7j43k on Sunday, December 9, 2018 10:51 PM

selector

 

Not so.  The cork is meant to be the roadbed, not the ballast.  

 

Well.......

Not exactly.

 

Consider the drawings below:

 

 

The roadbed is below the ballast.  The ties are embedded in the ballast.  There is a significant distance between the bottom of the ties and the roadbed.

Thus, the cork cannot represent the roadbed, because the cork is directly underneath the ties.  Even "worse", the cork is ABOVE where the bottom of the real ties would be.

So, the cork "roadbed" actually does simulate the ballast, not the roadbed.  It does, of course, do a pretty bad job of it, which is why we shower the assembly with (HO) ballast.

Roadbed is compacted dirt (ballast is crushed rock).  Roadbed, itself, is pretty rarely modeled.  There's an excuse, because the ballast tends to migrate over the top of the roadbed.  But it's still there.  As are the drainage channels paralleling the track.  Those, also, are rarely modeled.  And they are VERY significant. 

Ed

 

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Posted by SouthPenn on Monday, December 10, 2018 9:09 AM

Mabe the cork should be considered as the subgrade material.

I would think that concrete ties would have different requirements.

South Penn
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Posted by carl425 on Monday, December 10, 2018 9:37 AM

SouthPenn
Mabe the cork should be considered as the subgrade material.

There is no prototype analog for the cork.  It is a model thing only.  Real ties sit on and in ballast.  The cork is to elevate the track so it looks like it's resting on ballast.  Imagine trying to lay model track on a pile of scale ballast.

If you really need an analog, the cork represents the ballast the ties sit ON, and the scale gravel represents the ballast the ties sit IN.

SouthPenn
I would think that concrete ties would have different requirements.

There're done the same way.

I have the right to remain silent.  By posting here I have given up that right and accept that anything I say can and will be used as evidence to critique me.

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Posted by 7j43k on Monday, December 10, 2018 9:43 AM

SouthPenn

Mabe the cork should be considered as the subgrade material.

I don't think so.

Looking at the drawings, above, there is a height given for UP ballast.  In HO, it's roughly 3/16".  Taking that same measurement (bottom of cork to top of ties) of my Code 83 Walthers on top of cork gives 1/4".

So the cork takes the place of the ballast, or at least the bulk of it.  It is a "ballast former", not a roadbed.  But try using those words to sell the stuff.

When you smear your scenery dirt up onto the edges of the cork, and apply ballast to the height of the tops of the ties, you will have a very similar cross-section of the UP's ballast.  Which is sitting on roadbed.

YOUR roadbed will actually be plywood.  Or foam.  Or, as some clever lad did, a piece of O scale cork "roadbed".

 

I would think that concrete ties would have different requirements.

 

 

It does seem so at first.  But I can't see what they would be.  The ballast, once properly tamped, forms a shell around the tie to keep it from moving.  It would do that for just about anything buried in it:  wood, concrete, steel, plastic,.......

 

 

Ed

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Posted by selector on Monday, December 10, 2018 11:21 AM

Ed, in our hobby the cork is the roadbed, but it also forms a filler to elevate the tracks in order to minimize the use of ballast materials and to which we can adhere the track elements so they'll stay put, a problem not faced by the prototype (who don't have to use track nails and glues but only ties, ballast, and spikes).  The sub-roadbed is the cookie-cutter or splines that we make to support both the cork and the tracks.

As stated earlier, really the cork has no equivalent, but it should be treated as roadbed/filler and then ballast can be added, either cosmetically or to keep the tracks in place once it is glued.  At least, that's how I use my ballast and glues, and my cork. I never use track nails except to temporarily mock up geometry for the tracks, or to keep gapped ends aligned while the glue sets.

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Posted by 7j43k on Monday, December 10, 2018 11:56 AM

Tom,

Railroad roadbed is the defining surface of the ground for the trackage.  It is a graded and tamped surface.  

For model railroaders, the defining surface is the "plywood".  It's graded (with little blocks of wood or foam) but has no need for tamping.

 

Overlaid on the prototype roadbed is ballast, ties and rails.  Overlaid on the model roadbed is a cork outline of most of the ballast, with ties and rails and a smattering of teeny rocks.

 

Cork is called "roadbed".  It is not.  But because it is a continuous strip, it would be weird to call it "ballast", because we all know ballast is rocks.  It is really a ballast former, as I noted.

But it will be erroneously called "roadbed" for the far distant future.  'Cause it's always been that way. 

 

Ed

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Posted by MisterBeasley on Monday, December 10, 2018 2:10 PM

In HO, I think the ties are thicker for Code 100 track than for Code 83 track.  Having worked with both, I found it much easier to get good results with the thinner Code 83 ties.

It takes an iron man to play with a toy iron horse. 

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Posted by SeeYou190 on Monday, December 10, 2018 2:29 PM

I have also been upset with the thin ties, I don't even want proper scale 7 by 9 ties. I would prefer the ties be closer to 3/16" of an inch thick. Way too thick to be prototypical, but once the ties are buried in ballast, who would know?

.

It is easier to ballast on thicker ties, bury them to the surface in ballast, and everything looks great.

.

-Kevin

.

Living the dream.

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Posted by Anonymous on Thursday, December 13, 2018 8:12 PM

HOnewcomerJ
ence, model rr track that has thin ties, (not square), is ready to look good on cork roadbed.  But now, years later, modelers are adding ballasting material to their railroads, AFTER installing the track, building it up inbetween the ties. This makes the top of the ties about level with the balasting "stones".  So my first questions is, why haven't modellers insisted that manufactures make the ties square, so the end result would be realistic? About 1/2 the thickness of the ties would be buried in their ballasting and 1/2 would still be visible above the ballasting.  (I suppose the ony way to get that effect would be to ballast first and then install track on top of the ballasting.  That's never going to work!  The track will never lay level so trains can run smoothly on it).

Code 83 ties are square.  

For bridges, check out Micro-Engineering and Central Valley.

Bridge ties are actually slightly larger.  I believe they are 10"x10".

 

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