I am going to scratch build a curved trestle approx 17" across and 14" deep on the bents. I planned on using the following. 3/16" Dowel,4x8 Cross Bracing & Sash,8x8 Ties & 8x16 Stringers. My question is. Will the dowels be correct size for a structure this size? 3/16" dowels are scale 14" round. If you have any advise it would also be greatly appreciated.
Most ‘tall’ trestles do not use round, ‘pile’ type timbers. From my observation, the pile trestles(driven into the ground) are usually ‘low’ type of trestles(under 20’ tall). Really tall trestles are built up using ‘bents’ built out of square stock. They usually have ‘stringers’ running the length of the structure. Also, they usually have some kind of masonary footings that they rest on.
Here is a web link of interest:
http://www.blackbearcc.com/trestlebuilding_barrett.pdf
Jim
I second Jim’s observation, for square timbers. I used Kalmbach’s bridge and trestle book for mine. I drew a full size template of the final track and built the trestle upside down of the templater. That way it just fit into the canyon and attached right on the track stubs. It was time consuming but easy. I cut my own scale timbers out of walnut on a table saw and band saw. For a trestle, ther are no curved bridges, only many short straight bridges, each one canted just enough to accomplich the curve. I did cheat and used curved lamenant pieces between the track and the bents.
To add a little further information re: piles or framed bents, I have the book Bridge and Trestle Handbook by Paul Mallery. In the trestle section it states that “the maximum height of pile trestles is limited by the length of piles available. Thus, pile trestles are virtually always under 25’ high”. The book does show two example of pile bents, and the diameters used in the examples are 12 inch and 14 inch.
It really depends on weather the trestle is on a common carrier or logging line and era. A trestle can have both pile and framed bent construction also. Round piling on the ends with the square timber bents in the middle where the bents are taller. The square timbered framed bent constructed trestle will have a foundation usually pilings. other bents, blocks, rock or concrete. A logging line often built trestles with haste so framed bent didn’t always get built with squared timbers. It also depends on what your perception or definition of all is.
http://www.quietlywild.com/qwpages/iconpages/hiway1.html
The caption states that this is “A colossal log trestle from the old Soo Line Railroad crosses the Jumbo River.”
http://content.lib.washington.edu/cdm4/item_viewer.php?CISOROOT=/clarkkinsey&CISOPTR=530&CISOBOX=1&REC=6 http://www.steaminthewoods.com/OregonandWesternTCo1_onTrestlewLogTrain_MLee.jpg Is a pic of fairly tall round timbered bent trestle on a logging line.
http://www.berrycreekca.org/photo.htm
The Berry creek trestle is a com
You won’t find many really tall wooden pile trestles these days but there are a few left in branchline service. The tall ones will be where there is a decent supply of pile timber (Oregon and Washington come to mind).
Umm 3/16" = 14 (HO)"?
According to my math: 87 * 3 /16 = 16.3" which seems kind of large for a pile (to me anyway). I preferred the gangly look from using 1/8" dowels. But if you could find 5/32" dowels those would be ideal - 87 * 5 / 32 = 13.6"
Regards,
Charlie Comstock
Rough guesses based on the photos previously posted: It appears that in the 1913 photo, the round pile with the guy sitting above is no smaller than 20" diameter (possibly as large as 22-24"); in the other photo, approximately 18" diameter.
Since all of you have been so helpfull I am going to ask another question. Since the trestle is on a approx 23" radius. Would you spread the ties on the outside of the curve or make the width of the bridge wider to take care of the radius? Would they have built a little elevation rise on the outside? Thanks in advance for your answers.
I admit not having scanned the pictures that well. Upon looking at the one you mention it appears the guys behind is about the width of the top of the pile. I’m not the tiniest guy around and and I measured 17" from outside left to outside right. The guy in the picture looks not quite as large as me. So I don’t think 20+" but they might well be 16" or 17".
Curiously it looks like only the bents closest to the camera are piles. The others look like they’re framed (unless they’re using square piles).
Regards,
Charlie Comstock
Yes, track was sometimes superelevated on curved bridges. Does anyone know what kind of speed restrictions (if any) would have been present on a curved wooden trestle?
Regards,
charlie comstock
http://s220.photobucket.com/albums/dd51/Hwolf_photos/Best%20of%20Wolfcreek/
Thought you might like to see some pictures of the Wolfcreek. I am a fairly new modeler and would love to hear your comments both good and bad. The layout is a 10’x16’ around the wall. The trestle is going on the side a little to the right of the Mine.
For a fairly new modeler that’s a pretty impressive layout! I can hardly wait to see what you’re doing in another few years!
Cheers,
Charlie Comstock
To me~ … best example of round/pile trestle is from Wikipedia.org. Just type in Trestle and these two are in southern CA. I’d guess these look like treated poles … lol… treated telephone poles and can stand the constant battering of salt water.
Anyone care to guesstimate the height of the one over the water?
About 10 meters.
Try the site below, it is a copy taken from the RGS prototype
http://members.cox.net/sn3nut/trestles%20part%201.htm
Good Luck [;)]