# Spacing of Trestle Bents



## RCE (Sep 14, 2009)

I am reworking part of my layout and need to move some trestles.
Right now I have a spacing of 8" on center. I will be spanning about 9',@ 4" above the ground. Would it look ok to have 18" to 20" on center spacing, or will there be sagging between the bents? I am using cedar fence pickets ripped to 1/2" x 1/2" for the bents and for the stringers. 

Thanks for your advice.
Richard


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## Dan Pierce (Jan 2, 2008)

Spacing can depend on what you run, A USA Hudson would not like 20 inches, but a LGB 2 axle engine might be OK. I would not go over 12 inches.

A bridge well made (metal) could go the whole 9 feet!!


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## Ironton (Jan 2, 2008)

Standard practice on the Rio Grande Southern was to space the bents 16 feet apart. If this was impossible and they had to space them farther apart, they increased the size of the stringers. You could possibly do this, increase the size of the wood you are using to allow for a longer span.

I know that physics does not scale, but here is the distance in some of the more common scales.

1:32 6 inches

1:29 6 17/32 inches (approximately)

1:24 8 inches

1:22.5 8 1/2 inches (approximately)

1:20.3 9 1/2 inches (approximately)

1:13.7 14 inches (approximately)

Hope it helps.


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## Totalwrecker (Feb 26, 2009)

I have seen folks add long diagonals to support the center, kinda like the pic, but pulled farther apart.








John


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## placitassteam (Jan 2, 2008)

1/2 x1/2 seems awfully small for stringers. If you want to go that size with long spans I would suggest using 1/2 square steel tubing. On my lift bridge I used steel tube inside a wooden stringer.


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