What’s a Gadgetbahn?

December 3rd, 2017 by ant6n

For some time, I’ve been meaning to write about German transportation systems like what’s an S-Bahn or what’s a Stadtbahn.

With the recent news out of Quebec, I figured I’d instead talk about a transportation concept that doesn’t actually transport anybody at all: the Gadgetbahn.

The word is a portemanteau of the English “Gadget” and the German word “bahn”, which means rail or train. A gadgetbahn is a speculative transportation concept that proposes to solve planning and financial issues via some sort of magical techno-fix, likely some technology that doesn’t even exist yet.

Classic examples of gadgetbahns are: monorails, “personal rapid transit”, maglevs, or the newest addition to the family, the “hyperloop”.

Proponents of these technologies may be referred to as gadgetbahn enthusiasts, or more derogatorily, “pod-people”. They often promise the sky in terms of reduced cost and increased speed and comfort, often with little consideration for capacity, risk, safety or realism.

Back to  Quebec: the prime minister decided he wants a fast transit link between Montreal and Quebec City, but not a train, because “we can do much more modern things now”.

Instead, he wants something “futuristic”, something from the minds of Quebecers. (note from editor: Sorry to pop his bubble, but Quebec is not exactly known for having a long history on the bleeding edge of transit technology.)

The problem of the gadgetbahn isn’t necessarily that it’s a techno-fix. It’s that it is a technology for the sake of technology, a shiny gizmo to brag about, with little regard to solving the actual transportation problem.

The transportation minister clarified his position himself: he wants anything you can conceive of, any project; innovate, come up with new ideas!

And somehow, some consortium sprung up ready with proposals, renderings, promises and deadlines to build a high speed monorail (“MGV”), and all they want is a quarter of a billion dollars to develop it.

Cost, Speed, Comfort
– The problem is geometry, physics and the Right of Way

The beauty of proposing a gadgetbahn is that since it doesn’t exist, proponents can make up all sorts of quasi-magical properties for their technology, which supposedly make it superior. Since there aren’t real-world examples, proponents can use the most optimistic theoretical scenarios they can come up with, and compare them with the actual performance of projects that have been built and which are bound to the constraints of the real world.

For example, the high speed monorail promoters claim their system is cheaper than conventional rail, because they could just use existing highway medians, with an elevated rail system where vehicles are suspended from above.

The “MGV” (monorail a grande vitesse), high-speed pods on elevated tracks, suspended from above

When you look at its basic structure, compared to conventional rail, this monorail essentially differs in the method of propulsion: instead of two wheels on two rails below the train, we have two wheels on one rail above the train.

The main conceptual difference between conventional rail and ‘MGV’:
the location of the wheels

Like for any gadgetbahn, the claim is that this new technology provides more speed, more comfort at lower cost.

But in the real world, these three aspects are always intricately connected and subject to tradeoffs – due to simple geometry and physics.

Want faster transportation? Then you need very straight tracks. Don’t have straight tracks but still want high speed? Then your trip will become a barf-ride, so less comfort.  Want to build cheaply in an already existing highway median? Well the highway curves are made for cars going at 100km/h, so your choices are:

  • slow down (less speed),
  • run inside the existing geometry at higher speed (less comfort),
  • straighten the curves (more expensive).

These problems will always come together. At the end of the day, you’re still pushing a metal can full of people at high speeds you can’t get out of issues of geometry and physics by changing where you put the wheels.

Going further, once it appears the basic problems have been overcome, the next issues become capacity, safety, energy and access (stations).

For example, Elon Musk is proposing to build tunnels with his “Boring Company”, which will supposedly be cheap, because the tunnels will be relatively narrow. This reduces capacity, because only smaller vehicles will fit in the tunnel. To compensate, he may propose that vehicles will run super close together – which will represent a huge safety issue unless they run slowly. A small tunnel with a lot of vehicles that are barely smaller than the tunnel diameter, running at high speed may become a death trap in case of emergency, if there isn’t enough space and facilities for egress. If somehow he manages to solve all these issues, there’s still the problem of getting everybody into this tube of his.

All these considerations come down to the one fundamental constraint on which everything else depends: the right of way — how much space do you have available, how straight is your path, how and where is the downtown access, and how much space is available at stations.

The Maglev

An example of this issue is the maglev technology (essentially magnetically elevated monorails). The concept has been around for ages. The Germans and Japanese have been developing the technologies for a long time. In the early 2000s, the Germans were able to sell their Transrapid technology to China for the Shanghai Maglev airport connector, a 30-km line. It was a pilot project, with the hope to eventually cover the whole country with maglev network.

The Maglev was seen as the next generation of trains, mostly by being faster. But there was also the hope that it could even be cheaper, by putting the whole track on stilts, without having large elevated bridge-like structures. But in the end, conventional high speed rail and maglev require similar geometries, a similar kind of infrastructure, and it turns out that the speeds are not that different (Shanghai Maglev up to 430km/h, conventional rail up to 350km/h, both with a maximum experimental speed of around 600km/h).

At more than 300km/h, a lot of energy is spent to overcome the air drag of the trains themselves, which makes these speeds uneconomical either way. So the propulsion system is kind of moot.

From a distance, elevated conventional high speed rail (left) and maglev (right) appear strangely similar – the requirements on the tracks are due to physics and geometry, so the propulsion method alone won’t give one system a clear advantage over the other in terms of infrastructure cost

All of these issues come together to make the technological choice a bit of a wash.

In the end it makes more economic sense to build from conventional technology which has been developed for a longer time, has multiple vendors, has existing infrastructure that can be built on top of. This way, you can upgrade lines for high speed service, while being able to run the new high speed trains on existing tracks inside cities or to other cities. This provides a huge economic advantage.

So indeed, although the Shanghai Maglev works, in an economic sense it’s a failure. It convinced the Chinese to focus on high speed rail: ten years after the opening of the Maglev, the country still had the same 30km of maglev, but built 20,000km of high speed rail.

(Oh and btw, I’ve taken the maglev, it’s not a very smooth ride; it rumbles like a rollercoaster)

The Real Issue: Economics

The real issue of using a gadgetbahn to solve a transportation problem is not really technical. It’s that it re-frames the problem to build an infrastructure as the problem to develop a new technology — now you’ve got two problems to solve!

The technical problem should really be solved through private investment, not public funding. Thus I view the ‘offer’ to develop the “high speed mono-rail” for “only” 250M$ with a great amount of distrust. If the idea is viable and the people behind it are competent, it should have attracted private investment, as there should be a potential to make profit selling the technology. After all, the proposal has been around for 23 years.

When proposing a completely new technology in order to solve a specific transportation problem, the major problem is Risk:

  • Technological risks: Will it even work? Will it deliver on claims? Will it have sufficient capacity?
  • Cost-related risks: How much will it cost to develop? How much will one kilometre cost once the technology developed?
  • Regulatory/safety risks: Will it be safe? What will safety requirements be? How fast will we be allowed to run?
  • Risks because timelines are not understood: How long will it take to develop? How long will it take to plan & construct?
  • Operating Risks: How much will it cost to operate? How much will it cost to maintain the infrastructure? Will automated/unattended operation actually be possible?
  • Risks because we need to build complete systems at once, rather than incrementally updating existing infrastructure.
  • Also, new technology means relying on a single vendor, which is again extremely risky, both in terms of cost and availability of the technology in the future: Will the vendor exist in the future? How much will they charge us once we depend on them, given the lack of competition?

For any technology that’s already existed and been researched for decades, and that may have tens of thousands or hundreds of thousands of kilometers of infrastructure built today, all these question are much easier to answer. There will be much less risk, and thus less cost.

Be distrustful of Gadgetbahn Concepts

Any time somebody in power proposes to solve an infrastructure problem by first developing some new technology, or by using some proposed technology that hasn’t been delployed yet, we should be distrustful.

Often, the proposal may simply be an excuse to not invest in infrastructure today, because tomorrow some techno-fix will come along and solve all our problems ‘for free’. This tactic may work especially well if the proposal includes an appeal to some futuristic dream or a nationalistic project.

The gadgetbahn may really just be a big diversion. For example in Quebec, the most realistic scenario to get a fast link between Montreal and Quebec is the “high-frequency train” proposed by VIA rail, which would link the cities with conventional rail. After repeatedly proposing high speed rail for the last 40 years and getting no support from the governments, VIA decided to propose a system that’s not true high speed rail – but it would use dedicated passenger rail tracks, allowing somewhat faster speed than today, and no interference with freight.

This would hit an economic sweet spot for VIA, allowing them to almost finance and build the system themselves, with only relatively little public support.

But the main problem is the access to Montreal – VIA hoped to use the Mont-Royal rail tunnel to access Gare Centrale. But with the REM light rail project pushed hard by the prime minister, the tunnel would be converted to light rail, an incompatible technology, which will cut VIA off. In some sense, the prime minister’s announcement that he wants some gadgetbahn to Quebec City means VIAs rail project would become obsolete, and the conflict would become moot.

So is it really just a diversionary tactic to hide the regional rail planning problems in Montreal?


Interesting related reading (and with thanks for some inspirations) by Alon Levy:
“Loopy Ideas Are Fine, If You’re an Entrepreneur”

9 Responses to “What’s a Gadgetbahn?”

  1. Peter L Says:

    Nicely done. I usually end up not reading your blog, not because I don’t like it or you, but because I get angry and can’t think straight when reading about REM! 😀

    Here, I think you’ve done a good job covering the gadgetbahn phenomenon something certainly not limited to Montreal or Quebec (see, for example, the gondola ride proposed for NYC).

    I expect to be posting a link to this in many discussions going forward!

    And remember: monorails, maglevs, and now hypeloops and robot cars are the transportation of the future! Always have been, always will be! 😀

  2. Mr.Chinaski Says:

    Not one mention of the Chuo Shinkansen Maglev instead of the Chinese one? Cmon

  3. Daniel Says:

    One note: Despite gadgetbahn may look german, it is not. Though ‘Gadget’ and ‘Bahn’ are known.

    Isn’t the new mayor of “ville de REM” against the mentioned mount royal solution?

  4. ant6n Says:

    @Mr Chinaski
    I mentioned Japenese development in the area; and the maximum speed (~600km/h) comes from that project as well.

    Tue Shanghai Maglev was mentioned to make a particular point. If you think this article is supposed to be a survey of speculative transportation technology, I think you may have missed the point.

  5. Zweisystem Says:

    Vancouver’s SkyTrain is a good example of “gadgetbahnenn”.

    With much hype and hoopla, the driverless ALRT/ART was said to revolutionize public transport.

    Well that was in 1984 and in 2017 Vancouver’s SkyTrain has not lived up to its promises of revolutionizing transit.

    Only 7 such system have been built in almost 40 years and its marketing name has been changed at least four times. ICTS > ALRT > ALM > ART.

    Even though SkyTrain is driverless, it costs about 40% more to operate when compared to light rail systems. Very expensive to build, up to 10 times more than LRT (1982 IBI Study for the TTC’s ART Study) to build.

    Vancouver’s SkyTrain system also has limited capacity and its Transport Canada Operating certificate limits capacity to 15,000 pphpd, unless about $3 billion is spent up grading the line and re building stations.

    To date, the taxpayer has spent over $10 billion on SkyTrain or about $7 billion more than if light rail were built instead.

    The big problem is that politicians , engineers, bureaucrats and academics have been bamboozled by the proprietary light metro and continue planning for more. The have deified the damn thing.

    The real winners of “gadgetbahnenn” are the owners of the patents, as all gadgetbahnen are indeed proprietary railways.

    And who own the patents for Vancouver’s SkyTrain? Bombardier and SNC Lavalin.

    Build with gadgetbahnen, better have a lot of cash, because they cost a lot, lot, more than advertised.

  6. Gaël Says:

    What about tilting trains?
    Aren’t they a good way of getting more speed and comfort without straightening curves, at a reasonable cost?
    And I’m not a mechanical engineer, but I feel like by putting the wheels above the vehicle rather than under it, you can achieve better passive tilting, since you could eventually let the vehicle rotate freely around the longitudinal axis of the track. I have no idea if this is actually considered for the MGV…

  7. Peter L Says:

    The UA TurboTrain had passive tilt. The Talgos all have passive tilt. The LRC had active tilt as does the Acela. All are bandaids for bad track. Put the money into the track.

  8. ant6n Says:

    I didn’t want to go into tilting. Yes tilting allow you smaller curve radius at similar comfort / speed levels. It’s a way to ‘trick’ the issues of physics/geometry/cost that I mentioned. But these tricks are possible with conventional rail as well.

    Firstly, it’s possible to use a lot of super-elevation on your tracks (i.e. tilt them). Since VIA’s TGF wouldn’t host freight trains, I believe the tracks could be very super-elevated.

    Secondly, tilting trains are possible as well (As Peter points out). We have to wonder whether having a frame within the train that the passively tilting carriage is hanging from is cheaper than having the whole track up on a frame.

    Further, passive tilting is a bit limited, because it’s reaction is delayed. Active tilting is preferable – again this is possible with either wheel configuration, but I think it narrows the difference in complexity of the two modes.

    Furthermore, there’s a limit to tilting at high speed, because of the rotational jerk.

    So that brings us back to a similar issue as before: the tilting trick is possible with both wheel arrangements, so the question is whether the economics and the risk of developing a unique solution make sense.

  9. Fraser Pollock Says:

    Many years ago when I was just out of university, I had job where I actually provided information for the public about other Gadgetbahn systems, when a certain railway vehicle provider (which will remain nameless) was doing possible LRT and Subway/Metro projects. One of my many duties was to show people how many of these so called future public transport systems were really just poorly tested concepts.

    The reality of many of these pieces of technology were not that they didn’t work but could not ever do many of the things that there proponents say they could do.

    For example, “Low cost construction” of the infrastructure usually meant that the people who designed the concept had a simple pre-built mass produced vehicle tech or precast concrete construction system in mind for the vehicle, vehicle rights of way (tracks) and stations. The reality was usually that the right of way construction technology was designed for a test vehicle that was 1/4 – 1/6 the actual size and weight of the production model. This meant whisper thin support poles shown in flashy pictures actually needed to be replaced with massive concrete pylons and decking, which are not cheap and or easy to build. Often they are very expensive to maintain over time. Or the building technology wouldn’t work or couldn’t legally be used for safety reasons in the particular operating and legal climate being proposed.

    My favorite was the constant claim of high speed (especially for Personal Rapid Transit Systems) when in the picture or diagram provided the station stops were in eye shot of each other. Forcing very high acceleration/deceleration if high speed was actually even possible. It goes back to the comfort level for the customer the article mentions.

    Maintenance and spare parts as well as other on going operational costs are often overlooked when gadgetbahn systems try to show how cheap they are. As with many proprietary transport systems the cost of things like, staff operations and maintenance training, spare parts packages as well as support equipment cost and supply are never included in the glossy promotion packages that possible operators get. This is assuming the company pitching the gadgetbahn technology even has these costs on file yet!

    Never mind climate can make or break new pieces of technology. For example, many of the new wireless power systems for LRT and other rail vehicles don’t work well or at all in snowy or overly wet ground conditions, not to mention if its really cold. These are not even pieces of Gadgetbahn technology but technology provided by well known international rail vehicle providers. Bombardier’s wireless ground based Pri-Move system for example, doesn’t work at all in snow or function well in damp surface conditions and temperatures under 8 degrees C. The one place where has been sold and functions well is in Saudi Arabia, where it is normally bone dry and very hot.

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