Bridges

Any chance for a photo of one or more of these bridges? In HO scale 85' is very close to a foot long. So for a 900' bridge you have used up just about 10' of RR space and 15' for a 1400' bridge. You may not have any choice but to condense them.

A radical alternative is swap to N or maybe even Z. They are both easier to get massive structures without using up all the space you have.

Jack

Scale bridges with train length?

A prototype 1400 foot bridge is most likely considerably shorter than the trains that run over it.  If you model all 1400’ of the bridge, but your trains are only 1000 feet long, the visual impact may not be what you want.

Perhaps scaling the bridge by the same factor you’ll need to scale train length would work?

Bridges

I would suggest making one bigger bridge and one "medium" bridge.

You have several issues.  With the bridges between 900 and 1400 ft long and 60 ft tall, fitting multiple "prototype" bridges is pretty much out.

First issue is the bridges are 60 ft or over 8" tall.  Allow an inch or two for the riverbed, that gives a "thickness" of 9-10 inches.  If you put the bridge on the upper deck and have 18" between levels, that means the area under the bridge will only have 8-9" clearance.  If you pull the lower level to the front and put it in a 6-8" deep "shadow box" it might work.  But that severely restricts the scene below the bridge.  And they are long bridges.  You can increase the distance between decks but that means more time/distance in the helix or a worse grade in the helix and a greater variation in viewing angles between the top and bottom decks.

13x15 U that means a run of about 38 ft , less 5 ft of "blob"/helix on each end, that leaves 28 ft of open run on either level.  Two decks is 56 ft  of open run (not in/next to a helix or turn back blob).  900 ft is about 10 ft.  Four 900 ft bridges means that 40 of your 56 ft will be taken up with bridge.  Even making the 4 bridges half the size of the shortest bridge, that means that roughly 1/3 of your run will be bridges.   Not really feasible by the time you add industries and yards.

I would suggest putting one bridge maybe 4 ft (350 ft) long and 50 ft high on the lower level to give the mass of a big bridge and then maybe another 3 ft long only 25-30 ft tall bridge on the upper level.  That would give the feel of the large bridges without dominating the entire layout.

I don’t think you have enough space to fit all that in.

My space is a little smaller than yours on 1 level and I have about a 1/4 to 1/2 scale mile of track. You have to make a list of priority for each feature and then design the most important feature(s) into a plan. I am representing 2 prototype miles compressed into HO scale. I can only model half the industries the prototype had. I made several different versions of the layout on track planning software before coming up with a balance I believe will capture the feel of my prototype in much less space. 
 

  "In Monon there is a small

I'd try to design the layout based on these two areas. One level with staging representing Monon and Monticello and it's industries and bridge , the other level representing Delphi and it's industries and bridge with staging at the far end representing everything else. Each level would still need a lot of compression and the bridges sized as Dave H  suggested above but it might be do-able. The other option is switch to N scale and greatly increas your apparent space( but I'd give an HO design a chance first)..Two towns is still plenty of railroad for one person to build and operate.  If you could design the staging as a double ended yard representing Monon/N&W staging you could then have a continous run for train watching and engine and rolling stock break in runs and testing.....DaveB

What fits and what might not

Hi,

it seems you have quite a task of compression... There are several routes to take...

1. just draw up a schematic plan of what you want to fit in the correct order. Group the plan into "layout design elements" that you can distribute in your room. I'd guess you can fit two towns per level, leaving a bit of running between them. The "bit of running" would be part of the space to fit the bridges in. However I think you might not fit everything in.

2. consider a "double-level dogbone" - that is basically a return loop, then a track around the rear of the layout, to the helix, around the front of the layout to the other return loop, back around the rear, helix, front. The bridges would go on the "rear of the layout" parts and might even be part of the backdrop for your town scenes. Obviously the bridges would be somewhat elevated, however only their tops would be visible.

3. Build your layout in N-Scale, but use a near-HO scale track plan. Use the extra space to make your layout seem bigger, rather than putting in more tracks. It will not allow you to fit twice as many things, but allow you to make everything seem more spacious.

One more thing...

Pick just a single town. Make it fit along just the center of one wall. Build that. Add a bridge to it Once you've built that and you've run that, build another section, then another. Embrace the TOMA approach - I think it is particularly suitable for a situation such as yours. Pick your favorite scene and build it, then the next and you'll end up with a layout that has as many favorite scenes in it as you can fit into your room.

Have fun!