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:



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.

High Speed Passenger Rail for America: Thanks But No Thanks


  • Relatively short distances (less than 4 hours).
  • High population density.
  • Good local public transport one you’ve reached your destination.




Jungfraujoch, the Top of Europe

We were tipped off by a colleague that visiting Jungfraujoch would be an incredible destination while in Switzerland.  Words like “glacier” seemed sort of cool, but when other words like “cog railway”, “narrow gauge railway” and “UNESCO World Heritage Site” were used, I was hooked.Sara was skeptical at best, her last brush with a mountain being a bait-and-switch experience involving a promise of “no hiking” and Grandfather Mountain in North Carolina.  As we got closer to making plans and buying tickets, her confirmations became more frequent, until we were down to a “There’s going to be no hiking, right?” every 10 minutes, along with a complete thesaurus readout of alternate phrases: long walking, walking up a hill, trudging, stomping through snow, climbing, etc.As we bought our tickets, we didn’t really understand what we were in for on the trip over.  Swiss railways are nothing short of spectacular, the Zurich Hauptbahnhof being a prime exhibit with its 26+ tracks, two levels, 2,900 daily trains, and over 340,000 passenger per day.  For a point of comparison, Beijing’s new West Railway station serves roughly 150,000 passengers per day on average, and while this is one of three Beijing stations, you’re talking a comparison of a city of 22 million vs. a city of 365,000.  OK, enough stats.  The point is, I’m not sure there’s very many systems in the world, even in small countries, that can get you to where you want to go and back on a 10+ connection, 10 hour journey.  We missed one of our connections in Bern due to a misreading of the schedule, but there was another option 20 minutes after that one, and I’m not even sure it mattered towards the end result.The trip involved five different trains out and back, and our route was:

  • Zurich -> Bern (Intercity Express or ICE, double decker coaches)
  • Bern -> Interlaken Ost (Intercity Express single deck coaches)
  • Interlaken Ost -> Lauterbrunnen (Narrow Gauge on the Bernese Oberland Railways)
  • Lauterbrunnen -> Kleine Scheidegg (Narrow Gauge Cog on the Wengernalp Railway )
  • Kleine Scheidegg -> Jungfraujoch (Narrow Gauge Cog on the Jungfrau Railway)

From Interlaken Ost to Jungfraujoch, each of these segments included multiple stops (see the route maps I’ve linked to) as we wound our way up the mountain from Interlaken to an altitude of 11,388 feet which makes it the highest railway station in Europe.  In case your curious, the Qingzang railway to Tibet holds the record for the world.Riding up from Interlaken was a neat experience as the cogs permit a level of ascent that’s almost roller-coasterish in some places.  You pass by hundreds of small cottages, several small skiing and resort towns, and the train is carrying mostly skiers through the lower stations, complete with additional carts for baggage on the front of the train.  The railway is completely electrified, and though the equipment looks interchangeable, these are all separately operated railways with different uniforms, liveries, cars, and locomotives.  Typical of Swiss efficiency, the trains generate electricity for the line on the way down and can recover something like 40% of the power expended on the ascent.  As we progressed, we became a little worried that the top would be obscured by heavy fog that was blanketing the mountains, even though a train information official assured us it was clear on the top.The last two plus kilometers of the trips is at a very steep ascent rate and is completely within a tunnel with one stop for an observation point.  This last point is incredible, considering that this line was built in 1894 and 1912.We got a late start from Zurich as we caught the 10:32 AM train out of Zurich and the entire trip we witnessed frowns and mumbles about there not being enough time, and sure enough, when we got there we had 40 minutes until the last train, but for us it was enough.  We hustled through the station, rode a very fast elevator up, and emerged at the Sphinx Observatory whose very name leaves you unsurprised it has been used in a James Bond movie and as a setting for several novels.What a view!  We were high above the clouds, and in every direction there was snow, mountain peaks, and nothing else.  The lack of a visible rail line or road to the station due to the railway’s tunnel progression make it seem like you’re at some sort of Antarctic outpost having parachuted in, and the 12 degrees Fahrenheit temperature reinforce that impression.  We snapped off a ton of pictures, about froze to death, ran back down to the train, and were off!No hiking.Was it worth it?  I would say definitely yes.  If you’re a train buff, this is a can’t-miss experience despite the rather expensive cost.  For extreme environment junkies, I’d say yes as well.  There are hiking excusions you can take but those may only be available for the summer.  Our advice would be to go for a weekend or couple of days of skiing at one of the lower stations and head up for an hour as part of your larger experience.  An hour is all you need if you just want to see things, if you want to experience the restaurant or ice palace, maybe more time is warranted.