Hi everyone
Has anyone built one of these in a curved configuration? If so, can it be done in a 46" radius? ME doesn't offer a lot of details on their web site.
http://www.walthers.com/exec/productinfo/255-75550
Thanks
Dave
I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!
Not exactly the same bridge, as it uses towers rather than individual bents, but this is, if I recall correctly, a 34" radius:
This partially-curved one is, I believe, on a 46" radius:
To build both of these, I cut out the 3/4" plywood roadbed which originally spanned the gaps, flipped them upside-down and used them as patterns on which to construct the bridges, also upside-down.For either single bents or towers, the girders on the outside of the curve are used full-length, with those on the inside shortened appropriately. Both of mine are also on grades.
Wayne
Great bridges! You have done exactly what I want to do. Thanks for your response.
Can you explain how the curved bridge track mounts onto the straight girder sections? Is there any cutting or kitbashing required or can you simply mount curved track sections on the girders? It would be so nice if ME would post their instructions on the net.
Adding the track is just like laying flex track on a curve. I just eyeballed mine, but you could use centre marks at the ends of each girder as a guide. On broad curves like you're planning, you should have no problems other than choosing how to attach the track to the bridge. ME ties are not styrene, so the solvent-type cement used to construct the bridge won't work - you can use ca, epoxy, or contact cement. I don't recall which I chose, but I hope it was contact cement, as I don't like either of the other two for plastic-to-plastic joints. After the track is secured, add the guard rails and timbers - same choices for adhesives.
All of my bridges were built to fit their particular scene and there was no site preparation for bridge construction before the landforms were added. When it came time to build the bridges, they were built, as noted, upside-down and starting at the top. This meant that the footings and piers had to be built to accommodate the terrain, which was already in place - not the best way to go about things. All bridges are built as one unit (made it easier to take them outside for airbrushing, as they wouldn't fit in the spray booth) and all are removeable as single units - only the concrete piers, footings, and abutments remain on the layout. This makes it easier to add water effects and scenery, especially in those areas behind the first bridge shown, as the layout there is over 4' deep.
Here's a different bridge (a combination of Atlas, Central Valley, and Micro Engineering spans, and, like all of my bridges, on a curve) with some scenery in place, but no water:
The bridge was removed, water added, and the bridge set back into place:
Yes I have just completed one for the club but unfortunately I don't have the pics but I will post them asap. One thing I think is worth mentioning p/u the Nov.2010 issue of MR and on page 42 and read Tony Koester's article on "How to build a viaduct" The article showcases his modified Micro Engineering/Central Valley tall steel viaduct bridge he constructed for his NKPR extension. In the article he shows how he used a piece of 3/4" aluminum channel as a "spine" for the bridge and glued the Walthers bridge track right to the top portion of the "C" channel and then glued the girder section directly to the bottom of the Walthers bridge track. He needed to extend the M/E Z bracing with small styrene tabs to reach the girder sections.the actual bulkhead or abutment section of the bench work were notched out to accept the "C" channel so all the weight of the span is supported by the aluminum channel and not the actual structure of the model. Not detracting form the quality of Micro Engineering's or anyone else's kits but form an engineering stand point we can't expect scale models to have the same structural integrity as the prototype.
On my club bridge I chose to use all M/E components and the same 3/4" but we almost doubled the length of the bridge and I am confident in saying that over time the stock design would not have held up as well as what I now call Koester's bridge building method will. I have plans to build exactly the same bridge you asking about with pretty close to the same radius and it should be an easy build. I plan on using the 3/4" C channel but at the length of every girder cut a "relief cut up to the top surface and then a small triangular cut on the inside of the curve.allowing the C channel to bend in an arc, similar to what you would do if you used Homasote strips for roadbed you need to cut "kerfs" so the piece can bend Obviously the bigger the arc and longer the span the less the section will need to be curved. I saw Rick Rideout of Rix products use a similar method in one of the Allen Keller video's.
Good luck it should be a pretty impressive focal point on your layout.
I have done exactly the same as Wayne. Instead of the origional 3/4 ply mentioned, I had the pine spline to use as a template. Since it was spline and roadbed, it was easier to cut a new template from 3/4" ply. This gave me the exact starting point as Wayne. Note, however, I found it better to cut the template the tie width, I will explain the advandage shortly (save the cutoff scrap from the ply). If the configureation of the 30 and 50' girder sections of the 210' ME kit won't quite work for your application. not that ME offers these separatly. You could also modify the spans as did Wayne. The towers/ girger sections can be marked on your template (if easier, cut out cardboard version for the layout of sections. After layout the girder sections are "mitered" to angle of the curve. Take consideration of tie inside and outside to remain clean tie appearance on the girders.
Follow the ME instructions to the letter in the construction. They are quite good and concise.
When bending/ curving the ME bridge flextrack, you should use the tie width ply template (excess scrap ply) as a guide. This is the exact for inside radius for the ties. This eliminates and kinking and gives a smooth even bend. If you want to continue any superelevation of the curve accross the brige, shim the girder tops w/ appropriate girder width styrene strips. Once painted becomes part of the top girder. I found that to secure the bridge track to the girders, that Pliobond worked fantastic. It is a very flexable and stong bond. Pliobond is fairly transparent w/ only an amber hue. This can be doctored up by paint or weathering.
This modified version starts straight and eases into a 46" radius curve w/ super elevation.
I found that allowing the rails to extend beyond the abutments helped to anchor the bridge and also attach track feeders.
Modeling B&O- Chessie Bob K. www.ssmrc.org
Nicely-done bridge, bogp40, and a good photo example of properly-done terrain preparation for the bridge piers and abutments.
The post above are excelent and will be a great help for you, these are a ffew pics (not great) one is a plywood span of the radius I needed. I went for the wood on account I wanted a removable bridge, all bents and truss are a compression fit, I used 3/4 stock for the tapered bridge bases and measured with a caliiper mic to get the various heights I needed for the height.
I used this product as its a two part mix, sort of like a gummy clay, that can be formed to fit any embackment,ect dry extreamy hard. I used some plastic siding and pressed it into the molding material, so it would resemble the wooden form of the original concreat pour. This product is easy to use and forms just like modeling clay.
OOOOpppp messed up, wanted it added to the above, srry about that...Take care...John
Thanks everyone. Great bridges! I now have a much better understanding of how to accomplish what I want to do. Now you have me thinking about making the river valley deeper and wider for better effect.
Dave, if you would like to see a list of ME products or contact them directly here's a link.
http://microengineering.com/products_br.htm
They didn't have a wesite for some time, I used to call them directly. Very helpful, knowledgable people, have ordered many parts, accessories and add on kits for the Steel viaduct etc.
MicroEngineering, 1120 Eagle Road, Fenton, MO 63026 (636) 349-1112
You can call for full catalogue to order or use website.
* they also now have an open 80ft girder section to increase span between towers.
The description says "The various kits allow you to design and build your own custom bridge of any length from one to five stories high, with full towers or bents, and straight or curved" so it appears that you can build it in a curved configuration.
Cho Cho Willie
CDN Dennis
Modeling the HO scale something or other RR in the shadow of the Canadian Rockies Alberta, Canada
Sorry, I should have stated my question differently. I did see the part stating that they can be built with curves. The two issues I was concerned with were if they could be built in the radius I needed, and how the track is attached to the girders. Both questions have been answered very nicely.