Hi folks
I'm building 2 rather large curved trestles like I did on previous layout , the jvmodels instructions never really gave an indication of where to place supports and or the size of lumber to use. I seem to have misplaced my two bridge making books. I used 12x12 last time and went from bent to adjacent bent with two lengths on each side of a leg. Is 12x12 overkill? Is there any set technic for placement of the supports ? Obviously the busier it looks the better.
Lynn
Present Layout progress
http://cs.trains.com/mrr/f/11/p/290127/3372174.aspx#3372174
I did a search for "wood railroad trestle plan" and came up with some. Plans.
Those should answer your questions.
Ed
It depends on the intended/anticipated load and on the thickness and type of timbers available. Generally, fir would be preferred, or relatively knot-free cedar as it withstands weathering a lot longer than other woods do. Spans between bent frames would typically be in the 14-16 foot range for 12X12 timbers, but the stringers lying atop the caps would be more like 12X16 if they could be had in numbers or brought by relatively easily. Generally, the stringers would be arranged in four spaced pairs.
If you want your finished trestle to look 'busy' with a lot of gee-whiz about it, don't forget to include girts that run between the upright posts, lying atop the intermediate caps on tall trestles, acting as sabilizers for the intermediate joints in much the same way as the stringers do atop the top caps.
Then, sway braces on the outside of the bents, but also across their faces on all levels between caps. Should keep you busy for a month or so?
selector It depends on the intended/anticipated load and on the thickness and type of timbers available. Generally, fir would be preferred, or relatively knot-free cedar as it withstands weathering a lot longer than other woods do. Spans between bent frames would typically be in the 14-16 foot range for 12X12 timbers, but the stringers lying atop the caps would be more like 12X16 if they could be had in numbers or brought by relatively easily. Generally, the stringers would be arranged in four spaced pairs. If you want your finished trestle to look 'busy' with a lot of gee-whiz about it, don't forget to include girts that run between the upright posts, lying atop the intermediate caps on tall trestles, acting as sabilizers for the intermediate joints in much the same way as the stringers do atop the top caps. Then, sway braces on the outside of the bents, but also across their faces on all levels between caps. Should keep you busy for a month or so?
Thanks yes I did decide on 8x8's for Girts. Its how to lay them from upright post to upright post. Would they butt up to each other end to end or each end laying next to each other overlapping. Really struggling with this step. I did it on the last trestle but gave that trestle away and don't remember how I did it and can't find a clear picture as Ed suggested.
Some of these PRR "Standard Plans" may help to get you started...
http://prr.railfan.net/standards/standards.cgi?plan=79301-B&frame=YES
http://prr.railfan.net/standards/standards.cgi?plan=52396-B
http://prr.railfan.net/standards/standards.cgi?plan=59249--
http://prr.railfan.net/standards/standards.cgi?plan=59250--&frame=YES
Lots of great stuff here and since they're .pdf files you can scale and print them as needed. Browse the collection. There's Coal Tipple Trestles here, too.
Hope that helps,
Good Luck, Ed
wickman Thanks yes I did decide on 12x12's for Girts. Its how to lay them from upright post to upright post. Would they butt up to each other end to end or each end laying next to each other overlapping. Really struggling with this step. I did it on the last trestle but gave that trestle away and don't remember how I did it and can't find a clear picture as Ed suggested.
Thanks yes I did decide on 12x12's for Girts. Its how to lay them from upright post to upright post. Would they butt up to each other end to end or each end laying next to each other overlapping. Really struggling with this step. I did it on the last trestle but gave that trestle away and don't remember how I did it and can't find a clear picture as Ed suggested.
Below is one of the drawings I turned up:
Notice that the girts are 6" x 8". And also notice the drawing "DETAIL of GIRT JOINT".
Thanks Ed's this is great information and not anything like what I came across. I had my mind made up for 8x8 girts but I may have to rethink this now.
THis is a photo I took of the base of the very tall Kinsol Trestle on southern Vancouver Island, British Columbia. You can see all sorts of intricacies, enough to keep a veteran modeller busy for a long time. Note, though, the girts. They appear to be 9 X 4 inches in cross-section, and mounted with the same orientation as the stringers atop the top-caps, with the thin face down
There are indented butt joints and blocks everywhere, and lots of threaded bolts.
You coudn't climb up in there and get some detailed photos of girts?
I'm starting to feel there are many different ways of adding supports.
Here ya go. Notice the notching, both in the blocks in the foreground and in cap on which the girt rests.
Selector when I was looking at the scema I figured that's what it was was notched.
In the background,the girt is notched, not the beam. Well, it SHOULD be, because that's proper practice.
Notice what the notch in the girt does: the notch allows the girt to keep the two pieces it rests on from moving. It could also do that with a bolt or two. Which likely cost more at the time of construction. However. That piece of wood nearer us that forms the notch on the girt could pretty easily get sheared off, making the girt useless. A bolt would prevent that.
Ed I see that and it's the similar way as the tecnical drawino only the drawing shows it bolted. I don't think I'm going to get this anal about it.
Sorry. Being in construction, I'm around wood framing a lot, and find it more interesting than many others, I suppose.
7j43kSorry. Being in construction, I'm around wood framing a lot, and find it more interesting than many others, I suppose.
No need to be sorry Ed! I find these sorts of details to be fascinating.
I missed my calling to be an engineer or the like. That is probably a good thing because nothing that I touched in my various careers could have lead to disaster if I had mucked it up. I think the worst I did was to severly overcook a load of cheese sticks when I had a bakery. That was a lot of cheese sticks - 80 dozen! The cheese alone would have been worth $40.00. Big catastrophe!
Dave
I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!
hon30critter That is probably a good thing because nothing that I touched in my various careers could have lead to disaster if I had mucked it up. Dave
Being aware that one makes mistakes is the beginning of not making any. Well, much fewer, anyway.
Yes, construction can have bigger oops's than baking. Except for fire, I suppose. Which also happens in construction, as can be seen by viewing the news.
Anyway, I went over to a job awhile back, and noticed that the house next door had fallen off its temporary supports while being lifted. Oh my, a problem.
Another time was when a crew stripped off all the exterior siding on a second floor and forgot to put up any diagonal bracing on the remaining framing. Yup, another problem.