A new guy to the forums and a new guy back to model railroading after 35 years.
I started my fourth and final layout about two years ago. Being a carpenter and working with wood all my life I wanted to try something different. It was my thought to try something out of the ordinary. A 4x8 N scale layout could be constructed with the cookie cutter method using all foam.
The hardest part was planning the layout. I spent an entire winter doing a a full size 4x8 design on taped together poster board. That design carried over to the following winter until I got it right and then started the build.
I used 1 inch pink extruded foam and put all my risers 6 inches on center making sure in my design that a riser would never exceed 1/8 of an inch of rise in 6 inches of run. Therefore a 2% grade, close enough for government work.
When I had all the risers in place, before I put the cookie cutter on top, it didn't even make sense, it looked like Stonehenge. I wish I had a picture of that to show but it got lost in my phone, my phone ate it. From reading the forums I guess you're all familiar with that sort of thing.
When I put my cookie cutter on top of the risers it all made sense to the eye. It all flowed with natural gradual easements. I was very pleased.
Here is the original picture from about a year ago when my layout was just foam cookie cutter on risers before I put the filler pieces of the jigsaw puzzle back in at the appropriate levels.
Please tell me what you guys think. I would really appreciate some interaction and replies. Thanks make it a good weekend.
Looks like a good start, I still see a bit of Stonehenge in the upper left quarter of the photo. We would like to see how things have progressed in the past year, as well as some information on what you are modeling
George In Midcoast Maine, 'bout halfway up the Rockland branch
G Paine. Thanks for the good start compliment. Compliments always appreciated. Here is pictures of the upper left corner of the photo from both directions. This is a progression photo after the jigsaw puzzle pieces were put back in at the appropriate levels. No more Stonehenge going on here. The bridge I need to build in this area is a combination of kitbashed and scratch built. The blueprints for all my bridges are written on my poster board cookie cutter paper cut-out. I can refer to and place over the foam when I'm ready to build another bridge.
G Paine Looks like a good start, I still see a bit of Stonehenge in the upper left quarter of the photo. We would like to see how things have progressed in the past year, as well as some information on what you are modeling
I guess I didn't answer the second part of your question.
I am modeling Great Northern Cascade Mountains. That is why I wanted to create a lot of contrast. You can only fit so much in on a 4x8 layout. But it might as well look mountainous. The inspiration of Great Northern was from Burlington Northern that I grew up with and watched when I was a kid.
I had to go back a little further in time because I want to model steam. I like steam, it's got to be there.
Here is the original picture from about a year ago.
Here's a better bridge picture.
And another.
Here's some portals with the old ballpoint pen trick and then color washed with diluted paint. This is how I will finish my viaduct when I get to it.
Here's a better view of the double Warren truss Bridge. I think this view will make a nice scene someday when it's finished. Don't you guys just love S curves.
Trees, I've made plenty of these when I get bored doing something else. The thread is about grades of pink so I guess I better stay on subject. I want to stick to 100% foam creating my layout with exception of the light weight frame underneath it that it will be inserted into. So I have to build up to the different foam levels using foam and creating rocks. I did a sample experiment out of two pieces of 2" foam. This foam practice piece base under the trees took about 20 minutes including putting on tile thinset and diluted paint washes. The midsection, I nailed it that's what I want. The left side looks like some kind of hooty owl Cookie Monster thing with eyes. I must somehow delete that from my consistency of carving foam rocks and carving them fast.
I have to move in a year or two and although I will be hiring a moving crew I will be moving my layout. That's why I'm making it so lightweight.
Come on someone break the ice. I got to work on a Sunday tomorrow, too busy.
You all take care.
God bless. Maybe give me a shout.
We all weigh out the pros and cons for everything.
The nice thing about a foam grade layout is you can stick a sharpened coat hanger through anywhere you want for wiring.
I did iron out a little Stonehenge issue in back of the layout, lol with preparation for a number 10 turnout. It will be accessible but I don't want to access it if I don't have to.
From another way.
Capping off Stonehenge
An optical illusion. The mind plays tricks on the eye. The bottom right portion of the picture there is a turn out. After the split of the turnout one grade goes 2% up and one grade goes 2% down. Yes it's an optical illusion it looks steeper than it really is.
Edit. It's crazy how tall and roller coaster like everything looks before you put the pieces of the jigsaw puzzle back in at their appropriate levels then everything starts looking normal again.
This is the same corner after the pieces are put in
I like it.
Working on a around the walls shelf type layout in my older boys room. Engineering challenge to make it all work along with two liftouts. I just put up the first section a couple weeks ago.
I've been debating doing a slight grade once I get the other 2 long sections up. Foam is defnitiely sturdy enough to do it with.
Jeremy. Thanks for the reply. Your around the room shelf layout sounds like a lot of fun. Honestly if I had the choice that's what I would do. A 24 to 30 inch reach is really comfortable.
We are going to be moving in a year or two and downsizing as a stepping stone planning for our retirement. When we look at houses my wife looks at the kitchen I look at the basement, lol.
Foam works great for grades. The one inch thickness I used with my risers 6 inch on Center was very solid on its own but even more solid after I installed the cork roadbed.
I did a lot of experiments on adhesives. I found the best one for gluing foam to foam was 2 in 1 polyseamseal from Menards. It even way out performed blue foam adhesive. It stays flexible and hard to get apart unlike other glues I tested that get dry and brittle and just snap apart.
I'd like to see some pictures of your shelf layout you're working on sometime. Let me know if you have any questions about what I've been working on. I would be happy to help.
Looks like good progress is being made. Wish I could say the same for mine. Like Jeremy, I am planning an around the room shelf, but it will be a dedicated train room, only one doorway to contend with, probably a tip up. My problem is getting around to moving the current 4'x6' HO layout out of the 7'x14' room so that I can put up two walls against the foundation and a drop ceiling. I like to be able to run trains once in awhile, not much other place to set it up.
I am contemplating a grade on pink or blue, whichever is handy at the moment. I have 1", 2" and even some 3" from construction sites, though I do have some full 2'x8' sheets for the base. What I lack is a long enough space, so that I can have a reasonable grade. May just go with passing over a highway.
My small layout was to be a portable to go to local area craft shows, etc, to look for interested folks. Unfortunately the vehicle it was designed to be carried in died, new one, too small. Do have some N scale that I have thought of putting on a two piece, hollow core layout for a transportable one. Saw the design for an easy to build and use rack for the back of a small station wagon. However, the room layout will come first.
Do have a question for you. When you transitioned from flat to grade with the foam, did you have any problem with the foam "bridging" and not staying down on the base?
Good luck with your move.
Richard
Richard. Thanks for sharing. Sounds like a great project you got ahead of you. Feel free to post a picture of your 4x6 HO layout if you wish.
To answer your question I did not have any problems with the foam Transformations from flat to grade. In fact the foam made its own easement doing so. When I started the grade I put one of these 2 1/2" engineering screws in on the flat then put my first 1/8" riser 8 inches away for the beginning easement. Then my risers are 6" on center 1/8" higher every 6" to achieve my 2% grade. I put one of these engineering screws on every other riser by hand with a screwdriver. They have backwards threads on the top so they push the foam tight into the glue. The process worked really well I suppose I could have took the screws out after the glue dried but I just left them in.
The bridge I need to build in this area is a combination of kitbashed and scratch built. The blueprints for all my bridges are written on my poster board cookie cutter paper cut-out. I can refer to and place over the foam when I'm ready to build another bridge.
The card stock mock-up for my next bridge was incorrect. I referenced my 4'x8' cookie cutter poster board cut out. The correct one looks like this.
This is the rough draft of the next bridge I wish to build.
This is the stencil drawing I made with a few changes. I went with diagram A. I put it on quarter inch foam with a layer of wax paper over it. I then T-pin styrene (sandwich style) to the stencil drawing during the build.
My last bridge had 90 gusset plates. This new bridge would demand 190.
This isn't happening. I cannot get myself to do that again. Two times as many, ... I don't think so!
I had to come up with a design for a bridge that requires no gusset plates and still remains somewhat prototypical.
A design good enough to satisfy my thinking. I'll have to flip the (My bridge my rules card).
That design looks like this. It's a deep well C channel on top that has 20 inches, plenty of room for rivets. It has two shallow well C channels on the bottom with plenty of room for rivets. The center is an H Channel.
The plan is to start building this bridge next Sunday.
Take care.
Track fiddler
Edit Please excuse me as I post from my phone. Its kind of tough to do and I always have to go back and make corrections.
Hello Track Fiddler--
I would like to comment about the bridge sketch shown just above. First of all, I totally understand the need to make compromises on a model railroad, and that sometimes visual "tricks" need to be employed. As a professional civil engineer, I would like to respectfully offer a couple comments regarding prototype truss bridge design:
1. Although you can conceivably build a "model" bridge that represents a chorded structure as you have shown, in real life a truss bridge is inherently a very rigid structure. During the days when these bridges were commonly built we did not have access to the computer programs of today that can analyze quickly all the (moving=live) load scenarios. They were designed often by graphical methods, where from a chart, for a given axle loading, certain "rules of thumb" were applied to arrive at the most economical members and configuration. In classical structural analysis, as employed for at least much of the 20th century, a truss can be analyzed by hand for a given, static (not moving) loading condition, but the analysis would have to be repeated a large number of times to find the worst condition for each member of the bridge, because the worst condition for each member would occur at different times, as the simulated load moved across the bridge.
In the prototype condition, steel truss bridges, especially a more complex one such as the one illustrated in your sketch are almost always built in a straight line, tangent condition. To put kinks, or chords, or horizontal curvature into a truss bridge itself (track positions on bridges were allowed to vary) is almost unheard of in real life. Your sketch implies varying member dimensions that may result in a "normal" appearance when viewed from the side, but these dimensions would produce torsional (twisting) stresses in real life in what is otherwise a very rigid, "fracture critical" steel structure, which would not be recommended at all.
It would have been strongly avoided.
The Lehigh Valley and Reading Railroads did share one common truss bridge that had an unusual end configuration due to track curvature at one end. In that case a special truss arrangement of the end span may have been employed. That is the only case I am aware of. I saw photos, but it was years ago...
2. On a larger, more modern truss bridge composed of built-up steel shapes, where diagonals could take more than just tension forces, they would have been designed with thicker members to also take compression forces, as stresses may reverse as a moving load traverses the bridge. Due to the stress reversals, and to build some redundancy into the design, either the middle panel or the two adjacent middle panels of a main span would have had an "X" configuration rather than just a single diagonal in each panel. This guarantees that if one member failed (due to section loss from rusting), another diagonal can take the load, at least for awhile.
3. I understand that what I am saying would practically force you to change the horizontal curvature to get the bridge on a tangent. You can build the bridge as you have it sketched up, and I'm sure it will hold model trains and function adequately well. It just would look "odd" to anyone who practices civil engineering.
It's your railroad. Have fun with the choices made.
Respectfully submitted,
John
One solution that is actually employed by current day engineers would be to construct a tangent span truss bridge extra wide and just allow the track to curve across the bridge. Then you can maintain the aesthetic look you are going for without having to shift your track alignment nearly as much.
This is commonly done on highway bridges today where the road is in a long horizontal curve but we do not want to build the bridge itself with a curve. Often the roadway shoulder will be constructed extra width on the bridge so that a relatively smooth curved path along the highway is maintained. Most motorists never even notice the slight adjustment to a wider bridge shoulder width.
Some design professionals argue that we are "big boys (or girls)" now and should just sharpen our pencils to design more curved bridges. However, in actual practice today, horizontally curved bridges are still avoided wherever possible. Sure--with special training and really cool software engineers can design beautiful curved girder structures--but those more complex mathematical solution bridges all come at a price, that is not cheap, and they take considerably more effort to design and get approved (ie loss of time and money). So they only get used when there is no other "reasonable and prudent" alternative.
What's really amazing is how well built early bridges are, despite all calculations having to be done by hand, before computerized finite element analysis came into commonplace. But today - there are at least TWO computer 'games' I know about that present yoou with an obstacle to cross and a limited set of material from which to build a bridge, and then it 'tests' your design with live load analysis! And they are FREE!
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
rrinker What's really amazing is how well built early bridges are, despite all calculations having to be done by hand, before computerized finite element analysis came into commonplace. But today - there are at least TWO computer 'games' I know about that present yoou with an obstacle to cross and a limited set of material from which to build a bridge, and then it 'tests' your design with live load analysis! And they are FREE! --Randy
I am not disputing what you are saying at all.
However, there is a difference between "free" and "acceptable to your local state DOT".
By federal law, all public use bridges in the U.S. must be inspected every two years, and significant bridges, commonly interpreted as any river bridges, every single year, at least in the eastern U.S. The inspectors are looking for any cracks at all, difficult to see in steel bridges, which must then be photographed, measured, tested with dye penetrant to see how far they actually go, radiographed, etc. etc. Additionally, areas of section loss due to rust are measured after the loose rust is removed. Back in the office, the engineering staff is required to perform an updated structural analysis that takes into account any section loss of members due to rust. Then periodic "In Depth" bridge inspection and analysis reports are prepared and submitted to the local DOT or other governing/owning body. These reports detail all deficiencies and proposed corrective measures, along with cost to repair.
All this is done to prevent catastrophic bridge failures under traffic--and yet we cannot completely eliminate catastrophic failures--often they are a result of human error like a barge hitting a bridge pier.
Many of the existing truss bridges were conservatively designed, and are actually capable of handling 3 and 4 times the legal truck loads of today for the weakest members (ssshh, don't tell the log companies)--except that there is a finite, calculated fatigue life of the structures, as well. We have to estimate remaining fatigue life. Some bridges still have theoretical load carrying capacity remaining, but are at the end of the metal fatigue life, and should be replaced.
If the bridge is substandard width for today's vehicular traffic safety, either vertical wall parapets are installed to widen the deck, or it is tagged for replacement due to being "functionally obsolete"...
Historically significant bridges go through extensive documentation for the Library of Congress before they can be removed and replaced. The process can easily take 2 years. Sometimes, becoming rarer now, they can be rehabilitated and retained. Sometimes the new bridge is designed to retain the same silhouette and overall appearance.
I have to say I'm impressed with your work. I've done some building with foam, and we just glue, carve, file/cut.
I like your bridges, but it is interesting to read the bridge discussion, too.
Gary
John. I would like to thank you for your reply. I appreciate you taking time out of your schedule dealing with real Bridges and sharing your knowledge relating to my model Bridge. Nice!
I am not at all offended or discouraged as I found your information very informative and interesting.
I'm kind of learning maybe having a carpenter design a steel truss bridge is kind of like giving a monkey a hand grenade. Lol. In my design I mixed a bowstring truss Bridge with a pratt truss Bridge. I'm sure you can see that. I guess cosmetically pleasing to the eye is not always practical in the real world is what I learned from you.
From what I gathered from your information my bridge design probably would work for a pedestrian or bike bridge over a highway, but certainly not at bridge for a locomotive coal drag.
What's even funnier is if you look at my radius going over the sections of my bridge design in my stencil drawing. It's way out of Center. I was completely dumbfounded and kept running back and forth from my workbench to the layout wondering why the mock-up was perfectly centered on my layout but not on my drawing.
I found the answer later it was a mistake of overlooking common sense. I separated my bridge sections by 5/8 in my stencil drawing. A total of an inch and a quarter which scales out to 30 feet in N scale. A Far Cry from a 1/8 inch mistake.
I think I will go back to the drawing board which is just fine, I enjoy drawing. I think I'm just going to put together three Pratt truss bridges.
Thanks John
Thanks Gary for the compliment. It put a smile on my face after A hard day's work.
I do agree this bridge discussion is interesting, especially having an engineer involved in the discussion.