Elevated Trestle Steelwork Continues

Joe:

Amazing detail!  Really true to the NYC prototype - those diagonal braces and the cross-bracing "X" girders look great, not to mention the outside angle bracing.

I had only dreamed at getting close to that level of accuracy, congrats!

How are the bents progressing? There's a lot to getting those exactly "right" but I expect you've got that well in hand.

-Mark

Bents?  You mean curves?  For Dual Contracts they would be straight girders cut to various sizes.  Right now I will build standard 50 foot track girders.

The bents are the pillars and girders that attach the track girders together:

At least that what they are referred to here:

http://www.nycsubway.org/wiki/...el_Elevated_Railways

Can't wait to see more!

-Mark

Joe

If you need supports built to go with your girders let me know  We can cut them out of the hardboard  I don't think Plastruct will give you the strength for O scale subways

Joe, those girders, trusses and gussets are superb. What material did you use?

My plan is to build the cross girders to 6 scale feet.  I will use Gorilla super glue to connect ABS channels in an "L" shape on each cross girder.  This is where the track girders will sit.  For columns to placed on a sidewalk I will use lattice bracing to support the track girders to the cross girders.  I will make the elevated columns out of ABS channels and I-beams.

Ben, I have those concerns also and will keep you informed as to how this design pans out.  That is the reason I chose ABS over styrene. It is surprising however to see the how rigid the structure gets simply by adding bracing at the right joints.  What you see here is just track girders.  A whole lot more is still needed to construct a viable structure.  I have the book that contains the design of the elevated structures of 1915 to use as a guide.  That being said, it is possible that the Plastruct design could still be inadequate.  Then I will need to follow up with you.  I appreciate your help.  Your el structure at the NJ highrailers is very impressive.  How thick is the hard board used for your girders?  Would you believe the thickness of the ABS for the webs is only .030 inch.

ClutchGuy, I use Plastruct.

a true bachelor's kitchen  

Joe the hardboard is 1/8

Joe -

I think your method looks great! And, I can definitely appreciate the amount of work that goes into making the girders.

I wouldn't worry about the abs being strong enough, once all is together, it really is amazing on how strong everything is. What track are you planning on using? That can also be considered a part of the overall integrity of the structure. It would take wayyyy more weight to break the structure than running trains would ever have.

My structure is made out of a mix of 1/4" and 1/8" MDF/hardboard. The joints of the girders to the bents are reinforced with styrene angle to provide more gluing surface. I leave my trains on the structure and so far have had no failures. I did drop a section once onto the floor, and yes, that broke off some pieces, but it was a concrete floor.

I would recommend building the structure in sections then connecting these sections together (in a removable manner) to make the overall structure. That way, you can remove it to work on the scenery underneath if you have to. Also, if you can prepaint and weather before assembly that does make things a little easier (it can be difficult to reach into all the spaces between the girders).

Curves are definitely more challenging. I like to lay out the actual track and build the structure on top of the rails. That cuts down on the measuring. I did that with a new curve I recently added (a 90 degree corner where the two curves diverged to allow for an island platform). It looked like too much of a hassle to measure, just build on top of the track.

Some views can be seen on my blog: http://ctalayout.blogspot.com/

Keep us posted!

CTA Fan

Hi CTA Fan.  I will be building it in sections.  I will airbrush the structure.  I will use Atlas track and will design a track module to sit on top of the girders to allow for the catwalk and railings.  As far as curves go I am using RR-Track to design the structure.  If you master the z-axis capabilities of the software you can do a lot of 3D design.  Here is how I am designing the structure.

Joe

Very ambitious and a very impressive plan! I like the 3D view.

One suggestion, when you attach the bents to the girders, build it upside down, with the bents sticking up in the air. That'll keep the surface of the girders level which is essential for the track to lay smooth. Any differences in the height of the bents can be shimmed.

Also, to attach the track to the structure ... I use black zip ties around one of the railroad ties and around one of the cross members in the zig zag cross bracing. I attach it pretty tight and cut off the excess. It will hold the track securely in place, but if you ever need to move the track, you just cut the zip tie. Being black, put them right next to the center rail and they virtually disappear.

I'm lucky with getting to use center catwalks as the CTA does. Mine just sits on the structure, held down by gravity.

CTA Fan

Joe, this doesn't look like a modular structure.

Hi Brian..

From the perspective of looking at the diagram you make a valid point.  The way it becomes modular is as follows.  On a particular bench for instance that is 100 inches long you can have two 50 inch modules of elevated structure.  At the module joints the structure is not glues together, but each of the cross girders will have channels to connect to the track girders.  Those channels will be in an "L", on vertical glued to the cross girder, the other horizontal also glued to the cross girder at its end and maybe supported by a diagonal brace.  Both channels will be 1 1/4 inch.  The track girder will rest on the horizontal channel.  This will be the case for all cross girders and they will be glued, except at the module joints.