MisterBeasley I have an old Atlas model that had the official name of Chord Bridge. It's a totally straight bridge for straight track. In this case, I suspect "chord" refers to the curved shape of the top of the bridge superstructure.
I have an old Atlas model that had the official name of Chord Bridge. It's a totally straight bridge for straight track. In this case, I suspect "chord" refers to the curved shape of the top of the bridge superstructure.
MisterBeasley
A bridge built on a curve is not called a chord bridge. It is still called a curved bridge. EAch of the sections are chords in engineering terms. .
The Atlas bridge is called a chord bridge for the reason you said. the top support superstructure is curved.
A pessimist sees a dark tunnel
An optimist sees the light at the end of the tunnel
A realist sees a frieght train
An engineer sees three idiots standing on the tracks stairing blankly in space
pacbmanI am interested in the HO Creamery Junction layout in the October 2011 issue also listed as the Boston and Maine and Boston and Albany. One thing I noticed was the track curving across the straight bridges. Is that prototypical? And if not how could that be remedied? Also the upper level on the left end protrudes almost 4' from the wall. Any ideas on ways to support it?
Welcome to the forum. Your first few posts are moderated and will take a while to appear, but that passes quickly.
That track plan is actually from the December 2011 issue and subscribers may find it here:https://www.trains.com/mrr/how-to/track-plan-database/creamery-junction/
As with many speculative (never built) track plans, this one might not be buildable as-drawn. It would pose access problems unless one could walk all the way around it (without adding more pop-up access hatches). If placed against a wall, as the drawing suggests, large sections would be out of easy reach from the front and it would be hard to view the back of the lower deck because of the upper deck (especially in the river area).
And as you correctly note, it would difficult or impossible to support the deepest portions of the upper deck without obscuring parts of the lower deck.
A better fit for your room and needs might be achieved by starting a design from scratch, especially if you don't have a lot of layout-building experience.
Good luck with your layout.
Byron
Layout Design GalleryLayout Design Special Interest Group
It takes an iron man to play with a toy iron horse.
I looked up the layout. A wide truss bridge with curved track. I'm sure it exists somewhere. Obviusly curved plate girder bridges or concrete causeways are commonplace...though they are segmented. I've seen bridges with curved tracks demolished and replaced with long span truss bridges in recent years and the curve became flattened and the approaches had to be totally redone. If that's what's being done today, I'm leaning towards "not prototypical" for curved track on wide truss bridges. So engineers must think it's a bad idea, not for structural reasons but likely safety.
short answer yes. That is a normal configuration of track on bridge. Long technical answer: There is no such thing as a curved railroad bridge due to the physics involved. What that are is a series of short straight bridge segments that are straight with the outside section slightly longer than the inside to give an angled meeting point at each end. Each section is also wider than the section would be if only straight track ran over it. This is called a chord. Or chord bridge. The track laid on that section is curved. So those bridges in the article should be wider and will require a little kitbashing to get it wider. Don't remember if that is mentioned in the artle or not.
shane
I am interested in the HO Creamery Junction layout in the October 2011 issue also listed as the Boston and Maine and Boston and Albany. One thing I noticed was the track curving across the straight bridges. Is that prototypical? And if not how could that be remedied? Also the upper level on the left end protrudes almost 4' from the wall. Any ideas on ways to support it?