Visiting the Tech Model Railroad Club at MIT

Last night I experienced the privilege of visiting the Tech Model Railroad Club on MIT’s campus.  As an avid model railroader, computer science major, and great admirer of books like Hackers and Accidental Empires, I’ve heard of the TMRC for most of my life.  As a kid, my parents bought the 1986 edition of World Book, which underneath the entry “Model Railroads” included a picture of the TMRC layout, something I’ve never forgotten.

tmrc station

The first chapter of the book Hackers tells how some of the earliest computer science pioneers were involved in the TMRC .  A few of the notable members were Alan Kotok from DEC, Richard Greenblatt the coinventor of the MIT LISP machine (which is housed next door in the MIT Museum), John McCarthy who coined the term Artificial Intelligence and helped developed the LISP language, and Jack Dennis who was one of the founders of the Multics Project (the precursor to Unix).  These members along with others helped coin the term “Hacker”, and inscribed within the “Dictionary of the TMRC language” was the (now immortal to all computer scientists) phrase “Information wants to be free.”  These guys were budding computer scientists, brilliant minds, mischievous hackers, and they were serious about controlling model railroads.

The first chapter of Hackers describes the interplay between trains, their control, and what the TMRC meant to different students:


“There were two factions of TMRC. Some members loved the idea of spending their time building and painting replicas of certain trains with historical and emotional value, or creating realistic scenery for the layout. This was the knife-and-paintbrush contingent, and it subscribed to railroad magazines and booked the club for trips on aging train lines. The other faction centered on the Signals and Power Subcommittee of the club, and it cared far more about what went on under the layout. This was The System, which worked something like a collaboration between Rube Goldberg and Wernher von Braun, and it was constantly being improved, revamped, perfected, and sometimes “gronked”—in club jargon, screwed up. S&P people were obsessed with the way The System worked, its increasing complexities, how any change you made would affect other parts, and how you could put those relationships between the parts to optimal use.”

tram system

For model railroaders, the TMRC is probably in the top 10 most famous layouts in the world along with names like John Allen’s Gorre & Daphetid, George Sellios’ Franklin & South Manchester, and famous club layouts like the San Diego Model Railroad Museum.  For techies, there is no other layout in the world of interest that’s anywhere in the TMRC’s league.

It shouldn’t surprise anyone that model railroading and computers have always been bedfellows – even today model railroading has led the way in developing standards around Digital Command Control, interfacing locomotives, signalling, and other controls to a computer, and the Java Model Railroad Interface has provided us the world’s first successful test case of the Gnu Public License (the GPL), the open source software license that Linux and much of open source code relies on!

card operating schemeWith all of this background, I probably undersold the importance of the whole thing to my college roommate and his wife who live in Boston.   When they asked me what I wanted to do during our afternoon together it struck them as a bit odd that I’d already emailed the club from Scotland, had the phone number, and was anxious to make sure we didn’t miss the window.

Walking into the layout room we were met by the wonderful MIT alumnus and club member John Purbrick. He proceeded to give us an hour long tour showing us the various control systems, buildings, car card operating scheme, points of interest on the layout, and description of future plans.

custom built throttleTMRC uses a home grown software system (written in Java with the fronted in Python, all running on Linux) to run the trains.  The layout is still using DC block control, and trains can be run via the main computer system, or engines can be assigned to one of the many hand-built walk around throttles.  All turnouts are computer controlled and electronically operated, none are hand thrown.  For each yard or town area, there’s a diagram of the track layout with numbers on the left and right hand sides.  By keying in the number 0 on the left, and the number 5 on the right for example, the turnouts are all automatically thrown to present a route between the two points.  It’s simple, elegant, and impressive for a home built system.  As Mr. Purbrick put it, “We use a home built system on this layout because here at MIT, we have some experience with software.” Trains are detected by the software using electrical resistance, so operators can see from the software whether a train is on a siding, train with engine, or no train at all.

The main level of the layout is mostly complete, but there are plans for additional levels, and the layout features several huge helixes.  All visible mainline track is Code 83, sidings are Code 70, and there is some Code 55, and all visible turnouts are hand built.  There’s also a tram system that runs on one part of the layout.  Rolling stock varies but includes locomotives from Atlas, Athearn, and Kato. The president of Kato has visited from Japan and brought with him a gift of a few locomotives and some passenger cars.

soda machine

The TMRC receives no financial support from MIT other than free use of the space.  Just like in the late 50s (and covered in the book Hackers), the TMRC is supported from the proceeds that are made by selling soda from a machine in the hallway, and they turn a tidy profit according to Purbrick. A hand scrawled note affixed to the machine explains where the profits go and encourages patrons to email soda suggestions to the club for inclusion on the menu.

These days there aren’t many members left, apparently.  Maybe a dozen or so, although anyone can join. There was only one other member there while we visited, and the club struggles to get enough people together for operating sessions. Apparently there are several other thriving clubs in the area, but I wondered if there wouldn’t be a population of students out there who might not know of the TMRC’s heritage, it’s incredibly complex computer control system, and its delightful layout?

playing tetris on a buildingAs we made our way out at the end of the tour, Mr. Purbrick told us that we couldn’t leave without seeing the Tetris building.  From the hallway looking through the windows onto the layout, there is a control box.  When activated, the iconic tetris music begins to play, and the windows of the skyscraper light up to represent tetris blocks, which descend.  You can play a game of tetris represented on the windows of a building modelled by the TMRC, all powered by custom software and hardware components.  The creator of Tetris himself has been by to see this particular implementation, and while it wasn’t quite finished, he is said to have given it his approval.

“It’s one of our better hacks,” said John Purbrick, and I couldn’t agree more.

It’s Christmas in September

This year, is going to be like none other.  While “the economy”, “healthcare reform”, [insert your favorite sports team here], could all be phrases or concepts you might think I’m describing, for The Wife that statement is most definitely applied to Christmas decorations.When I got married, I’d say the largest change I noticed culturally is how much time, effort, planning, and anticipation went into the annual decorating for Christmas.  The Sunday after Thanksgiving is of grave importance, and involves getting a Christmas tree (real NOT fake), and busting out crates of decorations, turning down the thermostat (we’re in South Florida after all), playing Christmas music, and drinking organic eggnog.This year I’m contributing a Christmas decoration in addition to the NC State themed ornaments I’ve contributed the past couple of years.  Knowing how The Wife misses snow and winter scenes, I’m going to attempt to build a 1×3 ft diorama Z Scale layout, which will be covered in snow and ice.A couple of weeks ago we picked up the engine, cars, and a test loop of track, and it was probably one of the more interesting sales experiences for the staff at Warrick’s Custom Hobbies as he would suggest logical models (cars and engines from the same railroad) only to be stuffed with an incredulous “But it’s NOT GREEN OR RED!”  He got the hang of it quickly and we managed to find contentment in a MicroTrains Line Canadian Pacific (red) GP35 locomotive, a Great Northern (green) box car, a Burlington Northern (green) box car, and a red tank car.We’ve got roughly 3 months to go.

Constructing an N Scale Crossing

In my latest Fast Tracks order, I also received my crossing fixture for a XX degree crossing, which will be one of the points of interest near the docks.  The crossing is conceptually fairly different from the switch, as it doesn’t involve filing rail for points or bending any rail into a curvature, but there are quite a few frogs to construct, and the guard rails are considerably more difficult to install, particularly the “diamond” configuration of rails in the center.In software, we sometimes build one to throw away, and it seems like that’s going to be the norm for me with any new type of Fast Tracks trackwork, as I often get the track very close on the first try, but make some mistakes along the way and learn from them, producing a much better second effort.One of my goals is to be able to photograph this layout (diorama to many) and get it published, and this is a pretty major challenge considering that while I’ve been armchair modeling for many years, I really have no experience other than the very basic items I did when I was in the eight and ninth grades.  This leads to an obsession with making sure the trackwork is bullet proof, one that the Fast Tracks tools supports really well with their adherence to standards and attention to detail.I started this entry quite a bit ago, and so have no completed both crossings (the throwaway and the permanent) and my only real challenge was cutting the isolation gaps and ensuring that the rails were perfectly aligned.  I had some issues with the fixture on making sure that things were perfectly aligned, but these were cleared up by using an NMRA gauge to double check everything.All in all, I’m very happy with the product and results.  I think that the crossing is going to add a lot of interest to the port setting, and seems to operate just fine with cars being pushed and pulled across the crossing by a variety of engines without issue.

N Scale: Hand built crossing using FastTracks fixtures with Code 55 Rail.
I’ll probably add another crossing in the maybe-never-coming third module which would involve an interchange.

Fast Tracks Tie Breaker

Yesterday I received and assembled my Fast Tracks tie breaker.  It is a very well thought out, well made tool that does what it claims: cuts down the time it takes to trim ties for the turnout fixtures from Fast Tracks.Here are some pictures.  I would highly recommend getting one of these with your Fast Tracks fixtures if you’re building more than 5 or so turnouts.

It includes a magnet on the upper right, so it clicks right into position and doesn’t need to be held in alignment.  Very well thought out, well designed tool.

Shelving is Up

I’m building the railroad in modules that are 1×4 feet, which is basically diorama size, and means I can fit them into a car, walk them up the stairs, move them, store them, etc., very easily.  I can also chain them together on the wall using commodity shelving that is lightweight and unobtrusive.Here’s some before and after shots of installing the shelves down in my garage.  Things I learned on this project:

  • Tap drills (hammer drills) are useful, no, required for cinderblock or concrete drilling.  Didn’t even know what these were.  Once the guys in the hardware store realized I was a complete idiot, they began to dumb everything way down.  “So you take the drill bit, and put it in the drill right HERE and make sure the sharp end is pointing OUT.”
  • ACE Hardware is the ultimate store for tools and any kind of service.  I hate Lowes/Home Depot.
  • I hate leveling things.

After installation:

Disaster Strikes

Well, I got the three switches installed, good lengths of mainline track put down, and decided it was time to run some trains.  I quickly soldered some feeder wires, hooked up the throttle, grabbed my favorite test engine (Atlas GP35 in CB&Q colors), and let her rip.  Immediately, I pop a short.  Check everything, try it again.  Shorts again.Turns out, when I was building my turnouts, I misread a schematic on the instructions (no fault on their part), and cut the isolation gaps in the wrong spots.  Majorly frustrating, as I also didn’t test the conductivity while I was building the turnouts.  Still, after I got over the initial frustration, I realized that this was a good chance to go back and revisit my choice for roadbed that I had made.I originally was going to stack up 4 layers of Homasote on my benchwork create the sea depression that I’ll need for my dock.  This made things heavy, and meant that drilling holes would be a major pain.  I’m going to go back and redo that so that it’s just one layer of Homasote, and cut through the benchwork for the water.  I’ve also decided to install Tortoise switch machines so that I can have power routed frogs and automatic controls, as I’ve already purchased 4 Digitrax stationary decoders, and might as well put them to use.  I also decided I didn’t like the look of the Floquil tie brown, and prefer the grimy black method.Stay tuned as I rebuild the turnouts, and fix the mistakes I’ve made.