Lehigh Valley bridge project

[amato1969]

N scalers:

Today begins my journey of modeling the two-track Lehigh Valley bridge over the Delaware River.  My plan is to relpicate four of the prototype's six deck trusses, plus the through girder over the PRR Bel-Del line on the Jersey side.

In addition to photos in the Morning Sun books, my main reference is the Library of Congress HABER web site.  I only wish those guys took some more measurements!  Thankfully, they did document the overall truss dimensions, and based on these, I am estimating the structural steel sizes -- I guess this will be validated by building the first truss.

Each of the 174-foot deck trusses scales to 13" in N -- four of these plus the small girder bridge amounts to a total span of about 58" on the layout.

I will state right up-front: I have zero experience scratching a bridge this large, but I have spent a fair amount of time planning -- and stocking up on Evergreen structural plastic!  I also have a bag of Central Valley "build-your-own" beams - these may work for the major parts of the trusses.

So, who else out here on Railwire has some bridge-building wisdom to share?

   Frank

[John]

Make masters, and then cast ..

The best series on bridge building was in RMC years ago .. Bridging Galts Gap ...

[Chris333]

Is there a link to a photo of this bridge?

[John]

here is an interesting link

http://www.deepsoft.com/~heller/cgi-bin/index.cgi/Workshop/Bridge/

[amato1969]

Here are some photos I pulled from the Library of Congress site http://memory.loc.gov/ammem/index.html.  You can see the Central of New Jersey bridge right next to (upstream) of the LV bridge.






  Frank

[Wlal13again]

Just an FYI, the 3rd bridge in the photo brought the Lehigh and Hudson River across the river on to CNJ trackage to get to Allentown. Easton PA/Phillipsburg NJ was a cool place for trains back in the day

[amato1969]

Here's a quick update.  I have the major beams connected to the top channel, using my template and a square as guides.  I beefed up the main (diagonal) beams using .040x.060 strip:



Here's a profile of an assembled Central Valley beam:



Next up - attaching the bottom "pin connected" steel and small vertical members...

  Frank

[amato1969]

Holy cow do I need to update this thread.  I have cleared the workbench and am ready to get this project back on track.  One change based on my available space is to include only 3 of the deck trusses; I will keep the two smaller spans on the east end of the bridge.

Here are two of the truss sides in process, with some of the diagonal pieces in place:



And a poorly-focused shot showing the bottom structure:

[71jeep]

Hi Frank...

If you need any additional pictures  I am only fifteen minutes from the bridge it would be no problem.

I have allot of good memorys of this brodge spent allot time fishing under it fishing and waiting patiently to see a train then excitedly waiting for the caboose.

[wm3798]

That's going to be quite a project!  Did you consider cheating the spans to be a little shorter so you could fit in all 6 of them?  Or did the idea of building the other two spans drive you to the brink of madness? ;D

Lee

[amato1969]

Yep, I considered more shorter spans, but doing just three is killing me!  Anyway, I wanted to keep the "wow" factor of the long trusses, so hopefully the hardest part (building the sides) is mostly behind me.

[chuck geiger]

Check out the 2007 Great Model Railroads from Model Railroader. N scale Penn Central
Lehigh and Delaware Division. Also the Lehigh and Keystone Valley Model
Railroad Club scratch built it in HO. http://www.webspawner.com/users/Lvlou04/index.html

[amato1969]

Chuck, cool layout pics, thanks for sharing.  I made some progress over the weekend, and am now starting to connect the truss sides.  Using liberal amounts of the TLAR method (That Looks About Right), I sized and cut some .020 sheet into pieces that will support the floor beams.  My super-fancy jig helps keep everything square:



And just to keep the motivation level up, here's a glamour shot of the prototype -- from bottom to top, LV (less track), CNJ, and L&HR:

http://www.bing.com/maps/default.aspx?v=2&FORM=LMLTCP&cp=qsf4y38qzt3b&style=b&lvl=1&tilt=-90&dir=0&alt=-1000&phx=0&phy=0&phscl=1&scene=18204601&encType=1

[TrainCat2]

Looks good so far Frank. I have the builders plans for this bridge and you are capturing the look really well. It's a very interesting bridge, looking forward to seeing more.

What are you going to do for all of the tension eyebars that make the bottom chord?

[amato1969]

Bob, you busted me on the eyebars!  I am using some small Grandt bolt castings for the pin connections, but I haven't figured out how to replicate the "bulged" part of the eyebars.  Maybe some round craft items from Michaels???

Anyway, this week I killed off some brain cells with the laquer thinner (my favorite liquid cement) and have the three basic trusses together:





Closeup shot of the corner (bad lighting):



Lots of diagonal bracing coming up!

  Frank