finally building layout

[LynnB]

Yep looks to be same layout as mine. Let me know if you need any reference pics , I have all kinds of them, my instructions were sometimes not the clearest to follow and I did quite a bit of research.

[Bigsteel]

the reference pics will help quite a bit on some of the unknown stuff.i have a cad drawing of a 20ft tall bandsaw at work but stuff like the log carriage,gang trimmer and pulley system (i hope to have a full overhead pulley system).but that wont be for a while.but thanks!--josh

[Bigsteel]

so i am about finished with the second bridge/trestle for my small canyon.its not big or fancy but it gets the job done .i still have to add the steel strap to hold the 2 logs on top together and some NBW castings.but otherwise its done.--josh

[LynnB]

Looks great Josh, only one suggestion would be to take a bit of time to rough up the wood with a rasp or razor size then give the entire bridge a wash with A\I, this will really make it pop.

[doctorwayne]

Josh, your bridge looks good, but I doubt that it's real-world counterpart could support such a load. The logs forming the span are supported only at the ends, and even if they could support the weight (not likely), they should be situated below the area where the rails would be, not at the ends of the ties.
Instead of a pair of poles at both ends, a number of driven pole piles, capped with 12"x12" (or larger) cut timbers would have provided good support while still maintaining the rustic charm of wood construction. For the actual span, either a pair of steel girders (Micro Engineering has them in 30' and 50' lengths) or a wooden truss would provide the support needed.
I'd suggest re-engineering this bridge for use as one for vehicles, and perhaps, while you're strengthening it, narrow it so that it's only a single lane wide.
Plausible engineering, combined with your obvious modelling skills, will lift this from "nice work" to "wow, that really looks believable!".

Wayne

[Russ Bellinis]

In addition to what Dr Wayne said, I think they would have supported the ties and thus the rails and trains with all four of those logs under the ties, probably two at or near each end of the ties and two more directly underneath the rails. I also think the those bents at each end would have required a lot more bracing in all directions, and if they were at the end of the bridge, the railroad would have used concrete or stone abutments. I agree with Dr Wayne that it would make a very nice vehicle bridge. It might be a bit narrow for a highway, but we have quite a few houses out here in California that have a driveway spanning a wash or creek that would use a bridge like that one between the road and the garage. I suspect that there are similar bridges used in driveways or on back roads in Appalachia, but I don't know for sure.

[Bigsteel]

i wouldnt want to abandon this yet,could i add 2 more pile inside the ones there and add more bracing then add some more logs lengthwise? i was thinking about making the inboard logs into wooden trusses.im not sure but would that beef this up enough.but remember the F-unit was just for size comparison.it will only be holding shays and small diesels.--josh

[Russ Bellinis]

I think you could salvage it. Think in terms of the bridge not only being strong enough to support the train that is going to use it, but it also has to withstand swaying ans twisting motion. You will need cross braces both ways to triangulate loads. In addition you should tie the pilings at both ends of the bridge together with triangles rather than bracing them to the bridge with just a few logs spanning the canyon, river, or what ever it is designed to span. If you have space on the scene (not sure what it is going to span) add two more pilings to each end making the trestle bents 4 pilings in a square with x-bracing in every direction. Then tie in some lower logs parallel to the bridge to give the bridge more depth, and tie them together with x bracing, kind of a wooden deck truss. It would not only support the train, but give you a more impressive looking trestle as well.

[Bigsteel]

i added extra support yesterday and will try to post pics today,in my bridge thread i needed someone to post the pics for me as this computer is a pos and wont do it.so if anyone wants to help out im chessie1992 on photobucket .if not,ill just post the pics on monday.--josh

[LynnB]

I'll see if I can help I found your pics ok on photobucket but not sure how to post them for you other than posting the links , definately looks stronger.

[doctorwayne]

That definitely does look stronger, although adding stringers under the ties, beneath where the rails will go, will make it even more plausible. Nice work on the retrofit.

Wayne

[Ralph]

I like the look of both bridge versions but understand that your revision is probably more "credible" in supporting a train. Nice, neat looking work!
Ralph

[Bigsteel]

thanks guys,i have to go so ill keep this short,the first pic is of my current bridges larger more complicated bother.and the bridge im building now WILL have stringers under the ties,i just havent gotten around to it yet,and of course staining.--josh

[e-paw]

looks great.

[Bigsteel]

ok,here is the newly reinforced bridge.i added 2 more piles inside the original 2,added stringers under the rails and finally a butt-load of diagonals on the sides to make wooden trusses.ill have to re stain it because the first staining came out kinda blotchy.--josh



hey wayne,does the reefer look familiar



and here is a better pic of the second bridge that spans the same canyon in fron of this one.it was alot more complicated as it had alot of internal bracing and it had tension rods on the sides.