December 8, 2011

Decision Matrix - the 300th Post

A few years back I was having trouble deciding on what layout to build. I had a bunch of N Scale modules and was trying to build a double deck layout. I had all the bench work done, but in looking at it I knew something was wrong. So I took an idea from work and built a decision matrix to help me sort out my thinking. I published this in a article in Model Railroad Planning 2006. You can see a copy of it here. I have an archived copy of the former layout website here.

When I decided to stop building my DRGW Tennessee Pass layout, I redid the matrix and discovered that the C&O Mountain Sub layout actually fit my givens and druthers (G&D) better. That matrix wasn't published, but the C&O Mtn Sub scored a 103. I had become bored with the Tennessee Pass layout by then, so I welcomed the change and started building the C&O Mountain Sub layout using my existing modules as a start. That layout was in Great Model Railroads 2011.

I have already related how I decided to switch to the USMRR Aquia line earlier in the first posts to this blog. But I never did a design matrix for it. Yesterday, Marty McGuirk was cleaning out old emails and sent me a copy of the C&O Matrix with a jibe that I should tear out the USMRR and go back to the C&O since it had the highest rating. That got me thinking, how would the USMRR Aquia Line score on the matrix, using the same criteria.

So I redid the matrix comparing the USMRR to the three previous layouts I was building in this house. Turns out, the USMRR scored highly, but not as high as the C&O Mountain sub. But it soundly beat both of the DRGW layouts.

This doesn't mean I am going to tear out the USMRR layout. The matrix is a decision aid and not a hard and fast rule. One of the most useful things you can do with the matrix is a sensitivity study. That is where you vary your G&Ds and weightings to see what how things compare.

I scored the USMMR a 2 for manageable  instead of a three because the wiring and track are simple, but I have to scratch build it all. If I had scored it a 3 the USMRR would have come out on top. The USMRR has the best waterfront design of any layout I considered. The others don't have a waterfront, but there were other plans I considered that did, so it is not a goofy as it looks. 

 I gave the USMRR a high score on big steam, not because it has C&O 2-6-6-6 H-8s and K4s but because the SMR 4-4-0s are big, beautiful and sound great. If I threw in battery power (assuming it works) then I'd add points for manageable and big steam.  I gave the USMRR 3 points for prototype modeling because of the information available at the National Archive. I would never have such good data on the C&O, and I had even less on the DRGW.

I could also change the G&Ds. When I built the matrix I was mostly comparing N scale layouts to each other. I did not look at different scales. Thus, the opportunity for figure modeling that O scale provides was not even a consideration in N scale. If I were starting from scratch, I'd add a G&D for figure modeling and that would tip the USMRR to the top. I could also add a G&D for the military modeling tie in. But if I did that now people would say I was cooking the books like a good beltway bandit.

So, it was a fun exercise.

As to swapping prototypes again, given that I am 55 years old and this project will take another 5 years, I probably won't build another "lifetime" layout. My next layout projects will be smaller, similar to British exhibition layouts. Some subjects I want to pursue once the Aquia line is "done" include a 1920s era steel mill in HO or P48. I also am intrigued by the idea of a Russian Front WWII depot in P48 using US Lend Lease equipment as well as Russian motive power (see the movie "Ballad of a Soldier" for inspiration.) It would feature some of the cool Tamiya 1/48th scale armor models now coming out. It would include an urban scene, perhaps battle damaged.

I just noticed that this is the 300th post to the blog. Amazing. Congrats to those to you that have stuck it out with me this long.


  1. Berine,

    Congrats on the 300th post! Thanks for sharing your progress through this blog. :)

    Ted DiIorio

  2. I think you should 'cook' the books and add those items if they are truly important to you. If you are thinking about WWII take a long look at Hawaiian narrow gauge on Oahu. Huge traffic with lots of military cargo. In On3 or On30 it would be something.

    Congrats on the 300th post.
    Philip Taylor

  3. Hello Bernard, Do you have any pictures of your Tennessee Pass layout? There were only a couple in the 2006 Layout Planning mag, and I would love to see a few more! Do you have any place on then net where we can see the great work you did on that layout?


    1. Try this. It is an archived copy of my former Tennessee Pass layout blog.