Do to a last minute change in plans I need a 5’ long bridge over a 40" deep gorge. I have already splined up to the edge but do to the look on the other side and an unplanned change in radius on said side, bridge requirements have changed. Any and all ideas greatly appreciated. Pictures would be great. I am thinking steel. Thanks.
Brent
At 5 feet long and 40 inches deep, it sounds like steel viaduct time to me. MicroEngineering makes two fine Tall Viaduct kits (180’ and 240’ high respectively) that sounds as if it might do the trick. I’m thinking that you’ll need two of the kits, as each kit is only about 3’ long. I used two of the 180’ tall kits to span a 6’ gap in my own MR, mine had to be built on a 34" radius (however the instructions cover ‘curving’ the spans very well). Also, with the taller 240’ high span, you get 50’ large girder spans to cover the distance from the towers, giving the bridge a much less ‘spidery’ look. Construction seems a little imposing at first, until you get the first tower built, then it’s pretty easy from then on. I think they’re terrific kits.
Here’s my Deer Creek Viaduct, made from two of the 180’ tall kits. Hope this helps.
As I said, this is made from the 180’ kit, the 240’ tall kit has larger 50’ long girders between the towers.
PS: Another thought: This months Railroad Model Craftsman has a very detailed article on how Dick Roberts adapted the ME kits to model the big Bear River Bridge in California, at one time the highest steel viaduct in the state. It’s got some terrific ideas.
Tom [:)]
Batman,
For the length of span you indicate (5 feet), you might consider continuing the center three splines through you bridge structure, using the girder pieces as outside overlays. Sure, you won’t be able to see through the bridge, but the resulting roadbed will be much stronger and more stable.
BeaverBill
Brent,
Are we talking about a deep V-style canyon, or more like a river valley? If it’s the latter, the bridge shown in the previous responses will work nicely. If it’s a deep V, you’d be better off with something like the Canyon Diablo bridge:
http://farm3.static.flickr.com/2032/2252840833_885b3ae817.jpg?v=0
I built a model of it in HO. Mine is actually scaled closer to N-scale, since the full-scale model would have been 6’ long! But that one only has supports at the ends and where the concrete footings are.
Thanks Tom. That may do the trick, and if I can include a curve in it I can expand my ravine from 5’ to 7’. That’s the distance I had in the plans to begin with.
When I ordered my Sunset models Selkirk I had to increase my radius on the other side to acommodate it’s requirements. (Best layed plans).
I noticed in your photo another line in behind the bridge and I will have something similar. Is it below the bridge and if so, how does it look seeing it through the bridge? I can’t decide to have my return line 6" above or 6" below the bridge which will be in the front. Below is definitely preferable because of other considerations but if you can barely see it then what’s the point. However if the view of the train is still relatively good through the girders that would be great. Thanks
Brent
A good consideration on the spline as unless you go to some effort you won’t be able to see down. As far as the ravine shape goes… I was planning on building a replica of the stoney creek bridge on the CPR’s mainline but that is years away (3 years to retirement). This is what the terrain will look like. And for now a kit bridge until I build the replica.http://www.rockymountaineer.com/images/media/image_library/rocky_mountaineer/exterior/stoneycreek.jpg
Brent
If the curved sections of the bridge are not at the deepest point of the canyon, a long truss-bridge span (say 120 to 200 feet long) could be placed at that point and a steel viaduct (composed of 30/50-foot girder sections) for the curved portion of the bridge. This would reduce the height of the tallest towers and make the bridge more interesting.
Mark
Mark
Tom, because of you I drove the 2.5 miles to “my” local hobby shop and bought the RMC mag you referenced. Having just skimmed the article and knowing you’re an NCNG – Bear Creek bridge fan, you better get started building NOW. It took the author six years to build his.
Mark
Brent–
That line in the background is below the bridge, but doesn’t dip under the bridge proper. The bridge ends at an embankment, and crosses the lower line about 6" further down the right of way on a through-girder overpass.
BTW, just saw the Sunset ad on that Selkirk (I’ve got the Z-6 Challenger on order from them) and that is one INCREDIBLY beautiful locomotive. Congratulations. I’ve got several Sunset brass locos, and they’re beautiful runners and good pullers. I think you’ll be very happy.
Mark–
Wow–you bought the magazine all because of ME? I’m honored, sir, belive me! I was kind of bowled over myself, reading about how long it took him to build it. Six years. Imagine. And the NCNG built the real one in a little under four months, LOL! But isn’t that one INCREDIBLE honey of a model? But it’ll have to be something I can only dream about, since I’m just simply out of ‘bridge’ area on the Yuba River Sub. Besides, that curved Deer Creek Viaduct too me almost six months to build–radius templates, cutting, filing, using language that I didn’t even know the meaning of the words–fitting and re-fitting–and that didn’t even include fitting the doggone TRACK! I found out through much trial and error that you don’t bend Sinohara bridge track like it was Atlas, unless you ENJOY stray guard-rails springing out and hitting you in the nose. One thing, though–after building that viaduct, I can put one of those darned ME towers together with my eyes closed. Funny thing about that–an N-scale friend of mine was listening to me hold forth on how complex the kit was and told me that the N-scale towers of the same kit come in four pre-formed pieces. You just cement them together and–VOILA! A tower. I almost killed him.
Tom [:)]
But isn’t that one INCREDIBLE honey of a model? But it’ll have to be something I can only dream about, since I’m just simply out of ‘bridge’ area on the Yuba River
Tom
You can always build it and mail it to meeeee!!! I have lots of bridge space left.
Brent
Brent–
Don’t get me going, LOL! On a certain thread of this Forum, I have been given the nickname “Bridge Tom” because of my propensity for throwing a bridge almost anywhere on the layout that I can find an excuse.
While I’m at it, and since someone mentioned the Santa Fe Canyon Diablo bridge and you yourself mentioned the Stoney Creek bridge, here’s another big bridge I have on the Yuba River Sub. Now I don’t know if it would work for you, but it’s an arched steel viaduct–this particular model is made by Faller of Germany, though I’ve “North-Americanized” it a little. It’s about 3 feet long, and is modeled after the Beichstahl bridge in Switzerland. If you wanted a central arch to help span the ravine, this might be adapted:
Another frequent contributor to this forum–ArtHill–has also built this model and “Americanized” it even more, and given it a much more spectacular setting. Hopefully if he sees this thread he’ll show you what he’s done with it. It’s another model very much worth thinking about. However, being a German import, it’s a little pricey, these days. But very much worth the outlay, IMO. And it goes together quite a bit easier than the ME viaducts.
Hope I’m not confusing you.
Tom [:)]
I would humbly suggest that you might consider revising your scenery a bit to accommodate a smaller bridge structure. Generally, prototype railroads prefered to avoid such acrobatics whenever possible, as they are costly to build, and more costly to maintain. They also generally require restrictions in terms of weight loads and speeds, which can also add expense to running trains. While such bridges certainly exist, and there have been a number fine models built along those lines, I tend to think like a typical railroader and try to figure a way to run the line less dramatically…
I’m such a stick in the mud!
Lee
Tom
That looks like a good choice and I have admired Arts work since I joined the forum. The foot print of my layout as it stands today is 15’ x 24’ but I have 1000 SQ.FT. total available to me for further expansion when I retire. Maybe as Lee suggested I should downgrade the size of this canyon and do the big one when I expand after I retire.
Brent
Lee:
You’re not a stick in the mud at all, LOL!
Unfortunately, out here in the West, in mountain ranges such as the Sierra, Cascades, Sawtooth, Montana Rockies, Canadian Rockies and Coast Ranges, there often 'just ain’t no way ‘round it’, because the mountains are geolgically young and spiky and still growing and the canyons are deep and often wide and to build around them would mean many additional miles of difficult cliff-hanging construction, which has it’s own problems (winter avalanches, summer landslides, expensive to maintain snowsheds, etc.) so often the only way to alleviate the problem is directly, with a big, expensive bridge or viaduct across a deep canyon.
So you end up with two choices of operational nightmares on the prototype. For myself, none of the 15 bridges on my Yuba River Sub are ‘for show’, they’re there because of the Sierra topography I planned in advance and the need to get the railroad OVER that particular topography. For instance, the number of bridges on the UP–formerly SP Cascade Division in Northern California would make you blink. And some of them are HUGE. But they’re not there because SP liked bridges–they’re there because they have to be there, otherwise the line could not have been built–or would have to have been built with line detours that would have made the whole route totally unprofitable.
It’s what railroads out here–and I believe Brent’s modeling the Pacific mountains–work. Bridges. Lots of 'em. And far more than the railroads would probably wish.
Just my thoughts.
Tom [:)]
Brent, Tom got me to try the berchstahl bridge and I love it. Building it was fun and time consuming. Amereicanizing it was a blast. You’ve seen the bridge so you know what I tried. It also showed up in MR this month. If you try it, share your pics.
BTW a ME bridge is next on my list.
Thanks Art I think I will indeed try the Berchstal as it’s quite impressive. Having spent so much time in the Rockies looking at some of those massive structures on the CPR mainline, well that’s what my layout needs for the right feel. One more question for you and Tom and any other bridge Guru’s who might be out there. What is a good way to fill the gap until the bridge is built? Should I use a 1x4 or continue to run the spline across and support it somehow??? Any suggestions greatly appreciated.
Brent
Howdy, Brent.
One question. Do you have to have curved track on any part of your proposed bridge? If so, you might consider the asymmetric loads on the structure, which will have to be allowed for.
If your track across the abyss doesn’t deviate too much from straight, you might consider a temporary through girder, AKA steel stud, with the track laid inside rain-gutter fashion. The raised lips of the stud provide a safety fence in case some piece of rolling stock decides to attempt suicide. The ones I use are all in hidden track, and are intended to be permanent.
Chuck (modeling Central Japan in September, 1964)
Chuck’s got a really good suggestion.
As to my own situation, while I was planning out the Deer Creek Viaduct, I simply laid wide-radius curved track on stacked and glued 4" WS risers. It wasn’t very ‘scenic’ but it did the job until I could fit the viaduct in. But spline would work very well–make sure you support it, though–as if I had to say that, LOL!–until you can work your bridge in.
Tom
Thanks guys. Chuck your timing is perfect. I was just going to take some old steel studs and stringers from a dismantled kennel building, to the metal recycler.
Brent
Now that you mention it, you’re right! In fact, my own beloved Western Maryland crossed the Potomac no fewer than 9 times between Hagerstown and Cumberland, 10 if you count the connection track to the B&O at Cherry Run. The B&O, built 50 years earlier, occupied the twists and turns of the river valley, so the WM had to shoot the straight line and dig and bridge as necessary.
Most of those bridges were in the 600-800’ long range, and the route was also punctuated by 5 tunnels, one of them almost a mile long! I guess the big difference is the bridge deckss were never more the 40 or 50’ above the river.
I stand corrected!
Lee
