The Curve

“Compromise is like the middle of the road; always safer to walk on than the edges.”
-Dwight D. Eisenhower-


The north end of the modeled portion of The Hills Line features what I believe is the signature scene of both the prototype as well as the entire Iowa Interstate Railroad: The IAIS’s deck-girder bridge in Iowa City.


The view from Google Earth shows how the bridge towers over both the industrial spur and the Iowa River. The Hills Line has just enough space along the bank for before curving west behind the City Carton warehouse.

Despite the appearance of a rather simple prototypical setup, I had problems emulating it accurately on my layout. Compounding that issue is the fact that this scene is so iconic for the area that I had to replicate this portion of The Hills Line to help establish the proper locale. This led me to two significant, but hopefully not confusing compromises in layout design and construction.

Compromise #1: Concave, not convex


I tried to make it work. I really did. And I know once this post is published someone will come along and show me a plan of how I could have made it work in our space. But despite my best efforts, the overall operational goals for The Hills Line turned the prototype’s convex curve into a concave model.

The scene, while iconic, is purely cosmetic. Modeling the deck-girder adds no “play” value to the layout. The limited space in our basement required me to give priority to those things that directly affect the operating scheme, which didn’t include the bridge area.

So placing it in an inside corner of the room led to an inside-corner design that’s reversed from the prototype. While I wanted to accurately replicate the scene, this compromise allows me to focus more on the operating aspects of the prototype Hills Line. It’s not ideal, but no layout plan ever is.

Compromise #2: The toy-track piece

Curved commercial turnouts are expensive, bulky, and of limited availability. So of course I used one on the layout.

Repeated plan revisions and physical mockups of the City Carton spur showed that, based on the aforementioned inside curve placement, the turnout to the warehouse would have to be in the middle of the curve itself. On the prototype the spur also sits in the middle of the curved track, but the convex shape allowed the prototype to have the diverging route of the turnout be the main track. I had no such luck.


Originally I hoped to modify a Micro Engineering no. 6 turnout to curve it to fit the space. I even sacrificed one of my code 70 turnouts to see if it could be done. Result: less than reliable. City Carton may not have the traffic levels of Stutsman, but it still needs service. Reliable service.

So I went out and bought a Peco Code 100 Settrack curved turnout. Turns out it fit without issue into my 24-inch radius curves and, thanks to some ME Transition Rail Joiners, blends into my code 70 flextrack.


It’s ugly, I admit. But the necessary reliability outweighs visual appearance. Besides, situations like this are why weathering products are made.

There are only a few model railroads that are true railroad models. Layouts where the owner/builder has taken significant efforts to replicate in exact detail the correct locations, arrangements, and spatial relationships as present on a prototype. The majority have some level of compromise, either in track layout, train length, or some other selective compression or omission of what was actually there.

The Hills Line is no different.






7 thoughts on “The Curve

  1. Perhaps a stupid question James, but have you flipped the arrangement around in the sense it’s the mirror of the prototype? On the google image, the carton plant is on the right, whereas in the trackplan it shows it on the left.

    I am in a similar position with a spur to a rice processing plant and wonder whether I am straying too far from the prototype. In my case it would mean not modelling it and having to find something else that could fill the space in a meaningful way whilst still be close to the real world.



  2. Jim, I think 99% of model railroaders probably have to compromise on modeling a prototype exactly due to space limitations and for operational reasons. I had to scale down one particular industry on my layout due to size and space considerations, if I had modeled this industry accurately, it would have been ten feet long.
    I also had to use Peco code 100 curved switches in two places on my layout with transition joiners to get the track to fit and work, and they’ve worked great!
    Btw, that bridge with its weathering looks great. Anxious to see all your upcoming updates….👍

    Liked by 1 person

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.