02-18-2009, 02:14 PM
Having never seen a truss bridge, curved (in the horizontal plane), and giving some thought to how a truss distributes weight and force, I would feel safe stating that the bridge cannot be "curved".
A curve can be carried by several short truss bridges, but I believe deck bridges are more often used, because of side clearance issues.
A steel, or iron truss bridge, supported by stone or concrete abutments, or iron or steel bents or towers, can have wood trestle approaches. I can't remember seeing an iron or steel truss bridge on wood bents. Deck girder? yes, truss no. I believe it has a lot to do with the way trusses distribute weight and force.
The "it aint prototype" reason, does have exceptions, so I can't completely rule out the "no truss bridges on timber bents" though, logic would tend to support it.
Then again, I'm not a structural engineer.
(Edit): In reality, bridges are designed to fit the environment. In model railroading, our environments are designed to fit the bridges. :mrgreen: :mrgreen:
A curve can be carried by several short truss bridges, but I believe deck bridges are more often used, because of side clearance issues.
A steel, or iron truss bridge, supported by stone or concrete abutments, or iron or steel bents or towers, can have wood trestle approaches. I can't remember seeing an iron or steel truss bridge on wood bents. Deck girder? yes, truss no. I believe it has a lot to do with the way trusses distribute weight and force.
The "it aint prototype" reason, does have exceptions, so I can't completely rule out the "no truss bridges on timber bents" though, logic would tend to support it.
Then again, I'm not a structural engineer.
(Edit): In reality, bridges are designed to fit the environment. In model railroading, our environments are designed to fit the bridges. :mrgreen: :mrgreen:
We always learn far more from our own mistakes, than we will ever learn from another's advice.
The greatest place to live life, is on the sharp leading edge of a learning curve.
Lead me not into temptation.....I can find it myself!
The greatest place to live life, is on the sharp leading edge of a learning curve.
Lead me not into temptation.....I can find it myself!