Pier Types for Double Track Cantilever Steel Truss Bridges

[NWP SWP]

Hello everyone, I am trying to plan and build a large HO scale double track cantilever steel truss bridge, what sort of piers should I use and how tall can they be at maximum? Also what sort of approaches should I use? Any tips on how to go about building it?

["JaBear"]

Gidday Steven, While I applaud enthusiasm and also don’t want to come over as a “Forum Policeman”, I do however note that this is your fifth thread on bridges in the last seven days. It is my personal preference but I like a degree of compactness.

 

To assist any prospective advisors, what I suggest you do now is.

 

 1) Post a photo of the prototype bridge you would like to build, or at least put up a workable link to the photograph.

 

2) Supply the either a drawing or, at a pinch, just the dimensions, horizontal and vertical of the area the bridge is to occupy.

 

3) Give some idea of where the bridge is located on your layout.

 

Also, do you have any preference as to what materials you wish to use, and to what degree of detail you wish to achieve?

 

Cheers, the Bear. 

[NWP SWP]

Hi, thanks Bear! I actually do not have a track plan or anything yet I am waiting for Robert Sprague to get to my plan (this is because I tried for months to plan it myself but no luck) anyway right now I am trying to collect the proper information so that when the time comes I am prepared! I am using two prototypes as the basis for my bridge and I have included a rough sketch. Also I have guestimated the length of my bridge in real life would be almost a mile long! but I have decided to compress it down to about 20 real feet and 2000 scale feet! Selective compression indeed! But I expect it to be still very impressive! I would like to use CVMW laced girders to construct it.

[NWP SWP]

Howdy, I was surfing the technological wonder that is the world wide web and I found a bridge called the "Fort Dodge Railroad Bridge" and I saw the support piers for it (picture below) and I would like to know could something similar to that work for a large cantilever bridge? Of course have taller stone piers then a tall steel tower!

[zstripe]

Steven,

Do the same thing I suggested in Your other thread I answered.....when You decide on a particular bridge, find a photo and post it and others can see what You would like to build and what You can do to accomplish that.

Look at the piers on some of these:

https://www.google.com/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=Cantilever+Bridge+examples+Images

Take Care! 

Frank

["JaBear"]

Gidday Steven, I would assume, looking at your other bridge threads, that you’ve been looking at quite a few different examples, and would suggest that because the piers vary from four individual piers per truss, for example, the Forth Rail Bridge…

http://www.myhighlands.de/wp-content/uploads/2016/01/Forth-Bridge-Zug.jpg

to one tall pier per truss, the Auburn-Foresthill Bridge…

http://www.highestbridges.com/wiki/index.php?title=Auburn-Foresthill_Bridge

that you choose what is most pleasing to your eye.

cascadenorthernrr

But I expect it to be still very impressive!

 

I’m into impressive, (and I see Frank has linked you to the Plastruct site in one of your other threads,(Edit: I see Frank has joined us here while I was writing this) see what I mean about compactness) but I should point out that 2000 HO scale feet is almost 23 feet, not 20, which admittedly is a mere detail in the greater scheme of things, except when it comes to purchasing materials.

 

And while not wishing to appear crass or indeed negative, I would suggest you do a rough costing exercise soon unless money is, of course, no object.

 

To be fair though, I should point out that my only scratch built bridge was built out of 3mm MDF and cut down 4x2 pine, cheap materials.

 

 

Most importantly though, Have Fun!!

Cheers, the Bear.

[NWP SWP]

I was thinking something similar to these.

[NWP SWP]

What I meant above is that the piers components are: (from top to bottom) similar structure to the piers of the Poughkeepsie Bridge that comes down to a joint where it changes to a sideways trestle style tower like those of the Fort Dodge High Bridge which comes down to another joint where it becomes a basic trestle finally a two side by side carved concrete piers like the ones on the Thebes Bridge at the base! Thank you.

[NWP SWP]

Here are some basic sketches I have made. From top to bottom: full view, tower (perpendicular to bridge), tower (inline with bridge), pier three view.

[Anonymous]

Pg 48 of the August 2016 issue of MR. 

Also check out Mark Dance's clinic from the NMRA convention in 2015.  It talks all about how to compress bridge designs.  Its called "8 Bridges for the Columbia & Western"

[NWP SWP]

I have the August 2016 issue of MRR I also have MRP 2016 where might the NMRA clinic be found in print?

[Anonymous]

cascadenorthernrr

I have the August 2016 issue of MRR I also have MRP 2016 where might the NMRA clinic be found in print?

 

Its online.  Unfortunately all you have is pictures and few words.  Second clinic:

http://www.nmra2015portland.org/clinic-list

I went to a lot of bridge clincs in Portland.  Most of them were excellent.

[NWP SWP]

Thanks!