I cant seem to find out how far trestles should be spaced apart. Is there a normal distance or is it something I should just set up so it looks good?
Do you mean side to side? Wooden trestle flare out from the top to the bottom, so the base is wider than the top. If the tracks are close enough together, then they will share the same trestle, like the recently burned one in Sacramento.
Not certain what you mean. Are you referencing the pile or timber bents? If so, that depends on a few things. Generally, those are in the area of 14 to 16 feet on center. Boxcab E50
Here is a link I googled up. It's for G scale but the info is all the same. http://www.btcomm.com/trains/primer/bridges/trestle/trestle.htm
If you email me, I can send you std rr trestle drawing. The zap file is big so the address you provide will have to be able to accept a 10Mb attachment.
Thanks for the replys and links. I am going to space the bents at 1.125" for a scale of 15 ft on center. Bob, my email will only handle 5 meg, but thanks for the offer.
BPACH, Simple answer. The trestle bent spacing is dictated by the length of the stringers. These are the big timbers that the ties sit on. The stringers are grouped in sets of three or four centred under each rail. The stringers are usually 32 feet long. The joints for the stringers are staggered to ensure that not all of the stringer ends line up. The stringer then has a trestle bent support at each end and one in the centre. This means that the trestle bents are at 16 foot centres or 1.2 inches in N scale. The one obvioius question is why are the stringers 32 feet long? Very simple, most saw mills had saw benches with 32 foot maximum travel. Made this discovery many years back when building my HOn3 Rio Grande southern layout. Hope this helps. Gary
It’s actually much more complicated than that. For details of trestle design theory, see "Railroad Construction, Theory and Practice" by W.L. Webb. For most trestles less than 30' tall, the bent spacing varies from 10' - 16'. Each railroad had it’s own specs that they chose based on many factors, such as weight load on the line, local lumber species available, and the cost of construction. The N&W for example specified 12'6" centers on their bents. The stringers were based on the weight load and span between bents. The PRR for example specified Yellow Pine stringers under each rail for locomotives less than 200,000 lbs. of: Two 10"x16" for a 10' span Three 8"x16" for a 12' span Three 10"x16" for a 14' span For locomotives of over 200,000 lbs. Two 10"x16" for a 10' span Three 10"x16" for a 12' span Steel stringers for 14' span
Mines are spaced 1" or 13.33' , at the time I figured I would never be able to put my fingers between if it was less than that !
http://www.blackbearcc.com/drawings/nASMp2.pdf says 12-18 scale feet. 3/4" to 1-3/8" Black Bear Construction Co. makes some good bridge kits.
Decades ago MR had an article that was very comprehensive including lots of scale drawings. I wish I still ahd mine. Maybe someone on TB still has the issue. Good luck
