by

K. Goltermann

In response to Francis Reynolds´ latest contribution

Among the many different dualmode concepts in existence I previously considered the HiLoMag concept to be one of the most impressive and innovative responses to the growing need for a dualmode system, although I disagree with some aspects of the concept. However with the surprising shift from levitated vehicles above the guideway to a MagLev system with vehicles suspended under the guideway, I believe that Reynolds and his HiLoMag team have virtually guaranteed that the system will only ever exist on paper.

In the quest to create the optimum, most high-tech and futuristic dualmode system we tend to forget that our preferred solution will have to be decided on by politicians with tight budgets and built by existing industries, for ordinary people to use. In the real world it is not often the most expensive high-tech option that prevails. The triumphant is much more likely to be a cheap and minimalist solution, providing off course that this cheap solution can actually provide the required service.

For starters. It is not easy to name a reason, which could justify a 200 mph dualmode system. High speed is not a quality that weighs in heavily when determining the requirements of a future transport system. In fact, the excessive energy requirements of high-speed travel create a strong case against any proposed 200 mph system.

In the real world it is more urgent to solve the problems of intolerable congestion on our streets, excessive land-usage for new roads, insufficient parking opportunities, increased pollution in our cities, far too many road kills and in the long term; finding a suitable replacement, any replacement, for the fuels that we burn in ever increasing volumes.

The speed we, at least initially, should design for is the 30-100 mph range. Remember that guideways will offer constant speed travel, so even the modest speed of 30 mph in inner city areas will be a tremendous improvement over today’s typical stop-and-go pattern. Most transport is of short range in an urban environment, and any dualmode system should reflect this reality.

With no desire for high speed we could, for reasons of complexity and cost, delete MagLev from our proposal. Note that I don’t want to do away with the LSM, only the MagLev part. Magnetic Levitation is an untested technology, at least in the configuration proposed by the HiLoMag team; it adds complexity and cost to a degree where few would be willing, or able, to buy the dualmode cars envisioned for HiLoMag.

Instead I will advocate the use of well-known and understood LSM for propulsion, using the same pneumatic tires for guideway-mode and street-mode alike. Pneumatic tires and the related vehicle suspension is not an obsolete solution. Quite the opposite in fact, as they have been developed and refined, optimised and improved to near perfection, offering excellent comfort and high safety. And contrary to any MagLev suspension, pneumatic tires and traditional suspensions have been steadily mass-produced at low cost by many independent manufacturers.

As for the replacement expenses, higher energy consumption, claimed lack of reliability as well as safety concerns associated with the use of pneumatic rubber-tires; this does not seem to be a real problem today, so why should it be so tomorrow. Further improvement of this mature technology can and will be introduced, if needed.

What about guidance and control? Well, pay a visit to MagneMotion's informative website to learn about a new, relatively simple technology, that could be integrated into a practical dualmode system. This promising technology, combining efficient propulsion, safe magnetic guidance, excellent control qualities as well as short-headway non-mechanical switching, is in my opinion a prime contender for any future dualmode system; and although I have no knowledge about the details of this technology, it appears to me that the permanent magnets utilised in the system would be a perfect choice for an affordable dualmode car.

An affordable dualmode car! That should be the focus of our efforts in designing and implementing a practical dualmode system. And affordability is exactly what, in so far, none of the countless dualmode developers have managed to include in their designs. They fail to do so because their high-tech solutions are too complicated and therefore prohibitively expensive to produce.

Dualmode vehicles are almost always envisioned with electric propulsion for street use. Never mind that electric vehicles are very expensive and difficult to manufacture, too heavy with outright lousy speed and range qualities and are in need of a costly battery replacement approximately every second year.

Furthermore developers duplicate too many sub-systems in their dualmode vehicles. Separate suspensions for street-mode and guideway-mode, doubled propulsion systems and sometimes two independent brake systems. The many pallet-type dualmode concepts are obvious examples of duplicated sub-systems, as an entire extra vehicle is actually added to the traditional singlemode car.

The HiLoMag concept has now introduced a mechanically complicated extra pantograph MagLev suspension, and only a couple of miles from here (Copenhagen/Denmark) can one now witness the first prototype RUF rolling on its short test track, equipped with duplicates of every conceivable system.

Who would build these complicated cars, envisioned for HiLoMag, RUF and others? GM, Toyota and VW? Not likely! The worlds leading manufacturers have through their activities obtained a precious expertise in building certain types of vehicles, using highly refined production methods. They will not voluntarily assist in creating a competing market for vehicles that they have no experience manufacturing. A market whose preferences would be anyone’s guess. To manufacturers such a market would resemble a lottery too much.

If we expect car manufacturers to show any genuine interest in innovative transportation, we would need to think up a dualmode system, where cars as we know them today are modified only slightly to become dualmode cars, while production techniques and most sub-systems remain essentially unchanged.

My recipe is straightforward. Retain the internal combustion engine, add a couple of simple magnets to the bottom of the car for LSM propulsion and replace mechanical steering with a so-called drive-by-wire system, where electric signals from the steering-wheel are modulated by a little computer and used to control an electric servomotor. Such systems have already been demonstrated, they are likely to be introduced in our cars anyway, dualmode or not; and the result could even be cheaper cars. Finally, separate the generator from the engine and connect it to one of the wheels, to ensure on-board electric power for street-mode as well as guideway-mode. Simple solutions work.

In this way we could produce a near optimum, but still affordable, dualmode car. And we would preserve the technological maturity and operational flexibility of our traditional singlemode cars. To sum it up! I strongly believe that any dualmode system should be designed with the difficult task of implementation in mind from the onset. And any proposal must build on our existing transport industry’s expertise and capabilities.

I will not claim that HiLoMag could never be built. Maybe my assumptions regarding complicated systems mass-produced at reasonable prices will one day be proved wrong, but I’m convinced that the choice of mechanically complicated solutions and untested technology will make implementation much more of an uphill struggle, than would be the case with a simpler system.

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Last modified: July 15, 2000