Wednesday, November 25, 2009

Designing my train layout - 2

One more digression before I begin describing the design process for my current layout. Every layout that I have built so far (five in all) has incorporated lessons learned from previous layouts and the current one is no exception. A schematic diagram of my old layout is included below.

When thinking about layouts from an operational viewpoint, I find it useful to think in terms of schematic diagrams (which are similar to electronic circuit diagrams) rather than actual track diagrams.A video of this layout in operation under computer control is included below:

The focus of this layout was a station on a single line (somewhere in Germany near the Swiss border since all the rolling stock was either Swiss or German!). There were two storage yards and trains would proceed back and forth between the yards through the station. From an operational view point, this allowed me to model meets and overtakes.

Some of the problems (and lessons learned are describe below):

  • Since the layout featured only a single station, there was really only one viewing position. After a while, this became a bit boring since watching the storage loops was not much fun. This led to the requirement that the next layout would have at least two stations.
  • It became very tedious to sort out problems in the lower level storage yard since access was so limited. This in turn was due to the fact that I did not have the room for a helix to connect the levels. I therefore decided to avoid multiple levels in the next layout.
  • Unused freight yard: I created a freight yard for the station because I wanted to combine some switching action along with mainline train movement. The intention was that freight trains would pick up and drop off cars at the station. It was hard enough to get reliable automatic operations on the main line so this little freight yard was never utilized. Automating a layout is enough of a challenge and in any case, I did not really enjoy switching very much anyway.
  • Inadequate storage for unused trains: This is a perennial problem with railway modelers. There was simply no place to add any extra storage sidings on the old layout. I therefore decided to incorporate additional storage sidings in the next layout.
  • Automating a layout requires a large number of sensors since the computer needs a good understanding of the location of a train. There were not enough sensors on the old layout and the sensors were not well located. These problems arose since I had not really designed my layout with automation in mind. It became clear that sensor locations have to be considered before designing the layout.
All of these lessons have been incorporated in the current layout to various degrees.

Friday, November 20, 2009

Designing my train layout - 1

As a child I grew up with model trains. I was given my first train set when I was just two years old. Later, at the age of eight, my parents bought me a great Triang-Hornby train set when passing through England. Modeling activities stopped in school and college. While attending graduate school at Syracuse University, I bought a small loop of N-gauge track and used to run a train around my computer, much to the amusement of fellow students.
When I resumed active railway modeling in 1992, I started with Märklin, a well known German model train company. One of my best friends had Märklin train set and I always wanted those trains. Photos of my old Märklin layouts can be seen here and here. For a variety of reasons (chronicled in more detail in this article on my web site), I decided on a new direction.
I finally dismantled my Märklin layout towards the end of 2007 and cleared the train area in my basement for a new layout. As such, I had a clean sheet of paper to work with. My layout design was constrained by a few factors:
  1. Space: My old layout was just 4 feet by 10 feet. I felt that there was some scope for expansion. After careful measurement and negotiations with my wife, I determined that the actual space available for the layout was was 14 feet by 7 feet. However, there is a furnace close to the layout and I need to ensure that there is enough room around the furnace. Hence, I lost a triangular a nibble from this space.
    Now, 98 square feet is not much compared to the large spaces available to the typical American modeler. However, I felt that even this amount of space would be a bit of a challenge. Larger layouts are more costly both to build and to maintain. Its all too easy to bite off more than you can chew in this hobby! The shape of the available space is shown below. The available space is the area in white with thick borders. The diagonal section on the left side of the diagram is caused by the need to leave enough room around the furnace. Another issue is that this has to be a free-standing layout since I need access to things stored around the room.
  2. Operating style: This played a very important role in shaping the design of the layout. The one clear requirement in my mind for this layout is that it must support fully automatic computerized operation. Consequently two sub-requirements became clear:
    a. A continuous run is absolutely essential. A point-to-point layout is simply not suitable for automated operation given the need to switch locomotives around their trains.
    b. There need not be any provision for local switching in industries and freight yards as is common in most American layouts.
  3. Carpentry skills: I am not much of a carpenter - I just don't have a very steady hand and am a bit impatient. As a consequence, I wanted the benchwork to be as simple as possible. A major consequence of this constraint is that I decided to go in for a single level layout. Apart from being much easier to build, its much easier to debug computer control programs if the trains are visible at all times.
  4. Scale is HO (1:87.1): This is because I have a lot of European outline rolling stock in HO that I would like to run on this layout. Also, a large variety of HO scale equipment is available from manufacturers around the world.
  5. Minimum radius for the mainline must be at least 24 inches: This would allow the operation of most modern equipment although even this radius is too small for longer cars like the Amtrak Superliner car which is 85 feet long for example (nearly a foot in HO scale). There will be a fair bit of overhang for the longer cars on 24 inch curves but at least, they don't derail.
After spending a week or so considering these constraints, I updated my copy of 3rd PlanIt layout design software and got to work. In the next posting in this series, I'll describe the actual design process.