Are you familiar with the prototype SPINS documents? I think they've been uploaded to the Pacific Northwest Rail Archive, although I haven't actually looked for them there yet. The FOBNR website may have them too. What I did was to find the diagrams (and shipper names) for the areas of the railroad that I model on my layout, and then re-draw them (in a PowerPoint document) so they used a similar layout and numbering system, but were correct track diagrams for my actual layout. I printed them all out into a booklet for operators, and then I took one of the booklets and cut the maps only out and pasted them on the front fascia. Whenever I make a track change, I'll edit the PowerPoint file, update the operator handbook, and paste up a new map on the fascia. Sometimes this also involves making some new waybills to reflect the new SPINS codes I've added.
Are you a member of the OPSIG? The April 2021 issue of their (excellent) magazine has an interesting article about using car tabs instead of waybills, and of particular interest is his suggestion to simplify ops by using just a two digit code for each unique spot - the first digit being the town and the second digit being the industry. In (perhaps foolish) contrast, by carefully copying the prototype SPINS setup, I am using a six digit code: two digits for the "zone", two digits for the "track" and two digits for the "spot" on that track. I believe the prototype may have had two more digits at the beginning of the code for the "region", for a total of eight digits, but since all of my railroad is in the Seattle Region I decided to leave those first two digits out of the system altogether (even though the prototype would have used all eight in their documents). I put these six digit SPINS codes on all my waybills, so an operator can simply sort the car cards by SPINS number and the train is automatically blocked. A cool idea, but only a couple of operators have actually figured out and used this method in the five years since I've been using it.
I think what I'm trying to say is that copying the prototype SPINS diagram on the fascial looks cool in a magazine, but may be overkill in practice on a real model railroad. The more I try to carefully copy the prototype, the more I run into situations where I need to back off and do what makes it the most fun for operators. Another example of this is weighing cars - I built track scales in Interbay and Stacy St. yards in Seattle, but yardmasters almost never use them because there is always too much more important work to do. They just park cars on the scale tracks like any other yard track, because there are never enough yard tracks!
That said, I'm very proud of my faux-SPINS diagrams and they do give a slightly more prototypical feel to the operation. The feedback I've gotten from operators is that they would like me to put building outlines and labels in the diagrams so it was easier to find something like "Scott Paper" without having to look it up in the handbook and find the number on the map. My plan is to do a major revision of the whole thing with shipper names on the maps instead of just the SPINS numbers. Then the SPINS diagrams won't look as realistic, but they'll be easier to use. Also, the switch numbers and the track numbers are redundant, so I might pick one or the other and eliminate 50% of the visual clutter in the maps.
Here's a picture of the SPINS diagram mounted on the front fascia of the layout, at Burlington. It really does seem like it would be better if the names of industries were shown on the diagrams, instead of just all those numbers!
I mentioned that I left off the first two digits representing the division, but the more I think about waybills and ops, it sort of bothers me that I don't have an easy way to code for, say Kansas City vs. say Minneapolis. I used to think that heading east over Stevens Pass was all I needed to know about a car or a train, because my layout only goes as far east as Skykomish, but now I'm realizing that they had Laurel blocks and Minot blocks, and these were combined at Hillyard in Spokane with similar blocks from Portland to make the through trains complete. So even though I have Zone 54 set up as Skykomish, I'm thinking about adding some additional Zones to represent the through blocks that would have been set up by the yardmasters in Interbay. That would work, but, again, would my yardmasters pay any attention to it whatsoever, when they're slammed already just trying to get the eastbound cars out of their yard? Probably not. So it's probably not worth it. I'm just thinking about it. The good news is that having a two digit code for zones gives me a lot of flexibility compared with a one digit code.
