Show me your Abutments & Retaining Walls

[Noah Lane]

Wow, I appreciate all of the submissions!  These will definitely help with my idea bank.


Bruce- since you seem to have knowledge of structural engineering, can you advise as to what would be more prototypical for a Northern California truss bridge (~230'): should I run a center pier, and no connecting upper cross member (between the two bridge spans)?  Or, should I use the connecting piece, and no pier -as if it were a single span?   

And model functionality is a factor too, of course, but in testing it seems to work fine either way.
 

[Noah Lane]

Also, what do you guys think about printable cement textures?   -kinda like what was used on Kaustav & Mouli's Wrightsville Port in N-Scale magazine a few months back.

If so, what is a good source for these printable textures?

[Philip H]

I've seen some at ScaleScenes (http://www.scalescenes.com/) that look good if you print them in a matte finish on quality cardstock.  My initial attempts with a laser printer had a slight green tint, but switching paper (of all things) did the trick.

I think these look best for flat surfaces laid horizontally, though I suspect if you work slowly and carefully you can get good results on vertical surfaces too.

[diezmon]

Here are a couple of mine.. Both are just foam.  The bricks are a light coat of spackle, then lines carved in it.

[TrainCat2]

[robert3985]

Wow!    Sure glad you're back Bob...

[mark dance]

Do you guys think I should have a bridge pier in the middle of the two inline truss bridges?  Until today, I assumed I would have one, but I was just considering if not having a pier would look believable.

Bruce- since you seem to have knowledge of structural engineering, can you advise as to what would be more prototypical for a Northern California truss bridge (~230'): should I run a center pier, and no connecting upper cross member (between the two bridge spans)?  Or, should I use the connecting piece, and no pier -as if it were a single span?   

Hi Noah...while I am not a structural engineer and so defer to those who are, looking at the pair of double tracked through truss bridges in your photo, the trusses do not look deep (tall) enough to support their weight + possibly two train weights over the full distance.  Two separate bridges would seem to be required and therefore you need something to support the adjacent bridge ends in the middle...a pier.

Unless the additional "connecting upper cross member" you refer to increases the height of both trusses by perhaps 70-100% of what they are  now, making the depth of the trusses enough to support the weight over that distance, I think you need the two separate bridges + the center pier.

Just my opinion from what I can make out in the photo.  A side-on photo would be clearer.

btw: Bob that abutment is beautiful.

thx

md

[Noah Lane]

Mark- yeah. i think i've come to the conclusion to keep the pier, and lose the upper cross member.

I did build similar abutments using "classroom" flooring tile. It looks okay in this picture, but I feel like I made the bricks way too big to be realistic.

[mark dance]

Mark- yeah. i think i've come to the conclusion to keep the pier, and lose the upper cross member.

I did build similar abutments using "classroom" flooring tile. It looks okay in this picture, but I feel like I made the bricks way too big to be realistic.

That looks pretty good to me although the ledge the bridge end is sitting on seems pretty deep.  I would think the ledge might be just a couple of scale feet deep...just enough to accommodate the bridge bearings ("shoes" ).  And don't' forget to add those!

nice work

md

[wcfn100]

Thank you for the correction.  It appears "bridge shoe" is in common use only in the model railroading community, I guess similar to the mistakenly used "turnout" to describe a prototype switch.

md

Not at all.

http://www.in.gov/indot/files/bridge_chapter_05.pdf
http://on.dot.wi.gov/dtid_bos/extranet/structures/bridge-manual/chapter-27/tc27.pdf
http://www.ngdc.noaa.gov/hazardimages/picture/show/280
http://www.iowadot.gov/bridge/policy/57BearlrfdJu13.pdf
http://www.ksdot.org/burdesign/bridge/lrfd/LRFD_3_14_JointsandBearings.pdf

That's just the first page of a google search.
 
Not sure why 'switch' vs. turnout is still an issue.  Lot's of prototype documentation on that. 

Here's UP documentation on their track work.

http://www.uprr.com/aboutup/operations/specs/track/index.shtml

The nomenclature is pretty clear.

Jason

[Noah Lane]

That looks pretty good to me although the ledge the bridge end is sitting on seems pretty deep.  I would think the ledge might be just a couple of scale feet deep...just enough to accommodate the bridge bearings ("shoes" ).  And don't' forget to add those!

nice work

md

That's what I thought when it was done.  I did make this pretty early on in my return to the hobby, and just kinda winged it.  I suppose I could take another whack at it.  One $0.79 tile will provide enough blocks for probably 3-4 abutments.

[Ian MacMillan]

I do it a few different ways

Anchor Cement:







And industrial flooring tile:

[Noah Lane]

Ian- the anchor cement one is exactly what I had in mind for my layout. Can you elaborate a bit more on how you created that abutment?

And thank you all for your contributions!  They've all been very helpful.

-Noah

[Roger Holmes]

Here's a large retaining wall that I've done with Evergreen styrene.



After painting and weathering.



Both sides of the Chicago River.  The ugly wall brackets are gone now.

[Ian MacMillan]

Ian- the anchor cement one is exactly what I had in mind for my layout. Can you elaborate a bit more on how you created that abutment?

And thank you all for your contributions!  They've all been very helpful.

-Noah

Noah,

Its pretty simple, I used some .040 styrene sheet and Tenax 7R to make a form, much like you would in the real world. The form had an empty space of about 1/4" that anchor bolt cement was poured into. I used metal window screen material in that void to help give the concrete some strength, much like real rebar.  I then made a mix of anchor cement that was about the consistency of cream and poured it in. I then placed a cap on the top of the form and held it on a Black & Decker Mouse sander to vibrate the form to eliminate any voids or bubbles. The form then sat on a desk at room temperature for a few hours to set. Peal away the form (its a one use thing) and then let the casting set overnight. It will be a dark color at first and then will move towards concrete gray. The styrene causes it to become shiny because of the smoothness, so I toned it down with several coats of Dulcoat.