Great Progress

Hey, It's further than I ever got with bridges on my old layout.  Looks great though! Bridges are the best. Us model railroaders love seeing our trains suspended in the air I think.

Luv it!

I love bridges.  Well done (so far).  Russ

More shots of the secondary main

In the background is the secondary main. Through mergers, etc. the railroad obtained this route but it sees a much less dense traffic load. Needless to say, it was not upgraded and the wood trestle on the one end is still in good shape for 40mph and that is sufficient for this railroad.

The trestle is made from AHM bents found cheap at various trainshows, etc. I had discussed making these in the previous post. Not bad for a little bit of evergreen styrene and some cheap bents.

The Atlas bridge does perplex me a little. I am not sure but I think the "bridge shoes" were molded into the bridge. I am trying to find my extra sprue of Walthers shoes. There are some rather large ones on those that might look nice under this bridge.

Secondary Main is first !!

The thought is was to work on finishing the bridge for the Secondary Main first, so I don't have to worry about being so careful around the other main. The Primary Main (I'll have to come up with a name at some point) is of course higher and closer to the front, so it would really get in the way.

I'm not sure I like how the ends of this bridge turned out, but A LOT of the "kitbash" followed the lines established by Atlas with the original kit. It is much more convincing than the original kit, so I'll let any inaccuracies exist. Besides, being in the back, it is most always going to be a 4 foot model.

The one thing I wanted was to try putting some bridge shoes under the Atlas truss. I'm really not sure how prototypical these shoes are, but I think it looks pretty good. Of course, all of this will be painted before the permanent installation occurs.

This is the overall look. The small piece of styrene on the end girder is certainly not prototypical but it is necessary to help line up the trestle that will lead up to this end. It will also help keep the trestle structure the same height as the bridge girders and that will result in a smooth track profile from the trestle to the bridge.

Just like the prototypical picture, a short trestle bent sits on the bridge pier to hold the end of the trestle. The small white piece of styrene on the bridge will fit right in the middle of the trestle.

And... Here is how the trestle looks when mated to the bridge. Overall, it seems like a really satisfying project. As I mentioned, there is paint needed after a little more styrene is added.

I love bridges too

I did not see the Curved Cord bridge you spoke of??

I like bridges as well, as documented in this posting of mine. In it you will find a few curved cord bridges

arched versus curved chord?

I guess that Walther's bridge is really referred to as an Arched Pratt instead of a curved chord? I dunno.

More pictures of the bridge and trestle on the Secondary

Here are more pics of the in progress structures. The trestle is made from parts from both an AHM Ruby Basin kit and AHM cheap train set "over and under" pieces. The white styrene is either evergreen or plastruct .100 x .100 which I believe translates into a 9" x 9" timber. All of them are scraped with a razor saw and lightly sanded with 100 grit sand paper which gives the plastic a more realistic appearance. On one side of the trestle, I added some beams two 9"x9" "sistered" together to make a 9x18 that will hold a steel grate walkway (Tichy Train Group 8001) along side of the track.

Here is a look at the future river valley the secondary main is down lower than the primary. It is kinda like an available real estate thing. The old Big4 Route was more direct with fewer railroad crossings and a better grade overall, so it became the preferred line after the merger.

You might be able to see a platform off of the trestle. This is something that I guess used to hold a barrel for firefighting water during the steam days? I am not sure it would still be in place, but as long as it is structurally sound, I doubt the railroad would spend time or money to remove it. There are two sizes of these in the Ruby Basin kit and this is the smaller of the two. The Tichy steel walkways will run to this platform on either end for inspection and service access to the truss bridge.

The barrels included in the kit seem overly big and out of scale. They come molded in half on the sprue and while looking at them, thinking they were huge, I realized they will make nice flower planters along the main street buildings. So, they are getting repurposed. As I sit here and write this, it occurs to me that this platform is so big that it might do a good job holding a signal of some sort. That might be a really nice finishing look?

Here is another view of what will become an anchor scene.

I just wanted to include this picture looking through the truss of the secondary and then onto the AHM trestle.

Someplace, I found these short (30' maybe?) Micro Engineering deck bridges. They just about fit on the other end of the secondary truss. I haven't quite figured out if I want to use these here, or if I want to put a 50' span in here. I do like the look of the short span, but it might end up being too small to look like it "goes" with the through truss.

Luv Dem Bridges

They always seem to add so much character to a layout.  It must be the transparent look of a train running though a scene but never going out of view.  Well done.  Russ

I Want One!

Great looking bridges! I'm planning to have one very similar to yours on my layout some day. That's a long way off yet, but I'll be coming back to your post for ideas!

Thanks for the feedback

Hey guys,

Thanks for the feedback, everyone!

Russ, I am not sure why I like them too. It is probably the engineering involved, perhaps the history? Last week, I walked the Big4 bridge across the Ohio River in Louisville, Kentucky. As much as I hate to see tracks get replaced by trails, I am glad this structure was preserved. It is incredibly massive and provides modeler's license. There is a prototype for everything, right? It was something to be able to touch rivets that were hammered in place in 1931, It is amazing to stare into the distance and wonder what was going through some workers mind almost 90 years ago?

Paul, just do it ! I have owned my basement for over 4 years and this is my first piece of layout. I really have no explanation for not getting farther on my layout. Believe me, building that trestle was A LOT of work. So, was making that Atlas bridge look less toy like. It was hard to imagine I had worked on that bridge over 5 years ago. One day, I just decided that when the day comes, my widow will not be trying to sell kits I bought 30 years prior and never assembled. So, here we go !

Brian, I remember that old Plastruct kit being one of the very first decent models for a through truss! It looks like you did well with it. I was never a fan of the old Atlas/Roco bridge, too European for me. Atlas did the same thing with the floor on the new bridge that they did with that old Roco one. I think one of the things that I like is the "lacy" appearance of the floor girders and bracing. Once the track is in, I am not sure how much of it you can really see, but sometimes, it is very important. I like how you have made your bridge serve a mechanical purpose. I use mine like real bridges that actually carry the load. I know some people do not.

Eastern Approach Span

First, I started off with my beloved cheap trainset bents and Evergreen styrene. The bents for the bridge support are all of the same size, so this takes at least 2-3 sets of these things to get enough bents that are the same size. The bracing is not quite correct, but I am using a little pinch of modeler's license and a cup of, "it's my railroad and it looks fine to me..." As usual, the Evergreen parts are scraped with a razor saw and then lightly sanded.

Per common practice, the bridge bearings are short pieces of timber that support the bridge on the trestle end. The other end will stand on ME bridge shoes on the concrete pier that also supports the truss bridge.

So, I have decided to use the 30' Micro Engineering span. I just like the look of these short spans but it seemed too short for the space. Interestingly, the 50' span was big enough that it didn't look right. So, the compromise was about 15' of trestle and the 30' bridge. One thing I have wanted to capture is the look of a steel bridge resting on wooden piers as part of a trestle.

I think there will be a road that passes underneath the 30' span, but it is going to probably be for a private drive for the last manufacturer on the river. That would explain the use of a steel span on the eastern approach while the western approach is still completely a wood trestle.

As I sit here and think about this, the steel span may not have the railroad's name or herald on it. It might have something related to the plant entrance? The plant/manufacturer is off the layout and if modeled at all will simply be on the backdrop.

There is not much to say about the following pic. I just included it to provide an idea about how the trestle stringers line up with the girders.

Here is what it looks like installed. Obviously, most of the benchwork will get hidden by scenery. I am trying to decide what I will use on the bridge piers. It will either be covered by styrene or textured with a texture paint to make it look a little more like an older concrete structure.

I'm not terribly sure what to do with the backdrop. It is a fairly narrow area between the track and the wall. Any ideas?

Air draft of 30'

There is only a maximum air draft of 30' under this span, so most barges should be able to go under it, but it excludes many towboats, since they should have an air draft of less than 30'. I mean that is still a good size tug, but many are much bigger than that. There is only one other industry beyond this bridge and then the river becomes too shallow and narrow for navigation.

There is a slight bend in the river and I think the Western bridge abutment will have a clearance gauge on it. Of course, there will be lit navigation aids.

There are smaller towboats on various inland waterways. Saw one years ago called the M/V Neff and haven't ever forgotten it. I always thought it would make a great model someday. Obviously capable of one or two barges at a time and the smaller size adds visual interest.

Here is a view of another small towboat. It might actually be getting fairly close to the 30' air draft, but I can't really tell.

Since I am doing my normal planning, "ad hoc" I decided to see what the Walthers carfloat would look like trying to transit this bridge span. The barge is built to be approx. 280' long, so it is way bigger than I expected in the scene. I will probably scratchbuild a petrol barge or something that is about half the size of this one. The beam is just fine and the air draft looks pretty good too. It's not too bad for half-baked planning on my part.

Just another view of the air draft of a loaded barge upbound on the river.

Whoa !!! Finally using my pink foam (XPS)

I know it sounds crazy but I finally started working on the layout again !

What I wanted to do was get the Mountains in Minutes material (the black looking stuff in the picture) used. Parts of it will be used to form the canyon walls. The wood frame on the front edge of the layout dips much lower than I would like for it to, but when I cut it initially, I had not considered making a slow and deep navigable river.

My delay came from the difficulty getting the secondary mainline built. It is hard to reach and the design elements to hide it as it goes underneath the primary main is hard to visualize and produce. What ultimately made me tear it out and start over was the trouble I had trying to make the bridge level from one end to the other. The picture below is still similar to how the the bridge will appear. The support structures will look different, but those will all be hidden by scenery.

Pink foam will make the base of the river and will rise on steep cliffs on either bank.

I see many people asking how to bond the extruded polystyrene (XPS) which is the pink foam. One day, I was reading the glue bottle for gorilla glue. It is a water activated polyurethane. I have never wet my styrofoam, but did learn quickly that the urethane cures through a chemical reaction. What that means is that it bonds without needing access to air. So far, I have had unbelievable success with this stuff bonding the XPS to itself or dissimilar materials. As you can see, there are gaps in the foam pieces. Those gaps can either be filled in with smaller pieces of XPS, but I can also use Great Stuff Expanding foam and I prefer to use that for filling gaps. So, as soon as I have more work done on the river scene, I will post more pics.

Gorilla and XPS foam

Yep, it holds a ton! 

One caveat though; make your bonds well away from the edges you might want to hot-wire cut.  The foam will sear away as expected, but the Gorilla Glue won't give up so easily.  You'll end up with unexpected strata in your cliff face.

Learned that one the hard way.  

How is access to the tracks if something derails on the

secondary mainline?  It looks like you might have some problems there.

Gorilla glue lessons

Boomer,

Thanks for the tip. I had not yet encountered that one. Do you find it gives you trouble when using just the hot wire cutter or does it give you trouble when using a rasp to shape it as well?

The secondary mainline and many places throughout the layout are going to have some difficult to reach spots. I am aware of this and am doing the best I can to mitigate problems with reaching a derailment. The layout is typically no wider than two feet and so it is fairly accessible. One of the main reasons that I am no further along with this is because I decided to redo the sub roadbed that supported the bridge/trestle on the secondary main. It wasn't level and I knew that was just going to create problems.