Response to Comments by John Hopkins on the Problems and Potentials of a National Dualmode System with Reference to the Autrans Dualmode Concept
Van Meter Lund, Autran Corporation
I agree with almost everything Hopkins says in his insightful analysis. I too am very dubious about the future of dual-mode systems such as described by Reynolds which require special vehicles movable in a normal manner on streets as well as automatically on guideways. However, I strongly believe that there should be promising future for an auto/passenger/freight system such as my Autran system in which any automobile old or new can be driven onto a platform or pallet and automatically carried toward a destination.
This is not a criticism of the Hopkins analysis. I am sure that he was not aware of my system as my website has been linked to the ITT website only recently. I agree with a great deal of what Reynolds has to say about the advantages of automated transportation. His proposed system is advanced and has a great deal of merit. However, the chicken-and-egg problem mentioned by Hopkins appears to me to be an insurmountable barrier to adoption of the Reynolds system (i.e. HiLoMag).
People are not likely to be persuaded to spend more money on autos that are specially equipped to travel on guideways when few or no guideways exist. People in government are not likely to ask for new taxes for construction of special guideways when very few of their constituents can be expected to buy the specially equipped and much more expensive autos which will be required for travel thereon.
The first few paragraphs of the Hopkins discussion raise issues that deserve very serious attention. He acknowledges that systems using a tight integration between vehicles and guideways may be effective in certain circumstances such as for passenger transportation in localized activity centers, "particularly in circumstances for which the activity center generates sufficient income to make the transportation function self-supporting". However, Hopkins goes on to suggest that tightly integrated systems raise serious problems when proposed for wide-area transportation.
Some problems arise from "issues associated with multi-jurisdictional coordination and public funding". Additional problems arise because the "technical evolution of each element of tightly coupled systems is, to a large degree, dependent upon parallel and simultaneous modification of each system component. In contrast it can be argued that one of the major reasons for the dominance of traditional aviation, highway and rail technologies is their adaptability"
Hopkins points out that "Vehicles and propulsion have changed, roads and track have changed, control system technologies have changed. But throughout, each change has - to a remarkably high degree - been independent of the others. More importantly, improvements have been substantially downward compatible' with new roads readily carrying old cars and trucks, and the newest vehicles operating successfully on highways constructed many decades earlier." He then says that "A key point is that these systems have thus been able to evolve, adapt to changing needs, and incorporate technological advances in a basically incremental fashion."
It seems that Hopkins is suggesting a system that can be built on relatively small scale and be self-supporting but is designed "to be able to evolve, adapt to changing needs, and incorporate technological advances in a basically incremental fashion." I submit that the Autran system satisfies these criteria. The Autran system can be self-supporting even when constructed on a small scale. (See my financial analysis). It has a modular design that allows suppliers to compete in improving and/or reducing the cost of any component without requiring changes in other components. More particularly, separate modules are formed by (a) load supports, (b) carrier vehicles, (c) guideways and (d) a series of electronic modules. Each load support may be either an auto platform, a passenger cabin or a freight container and includes standard connections to upstanding posts of a carrier vehicle for physical support, for supply of electrical power and for data communications.
Improvements can be made in the future as to the design and construction of a platform, cabin, or container so long as the standard connections are used. Another important advantage is that a platform, cabin or container may be physically transferred between two vehicles or between vehicles and storage or servicing locations. A freight container may be transferred from a vehicle of a system operated in one state or region to a vehicle operated in another state or region and continue toward a destination. A passenger cabin can be carried at a relatively slow speed vehicle to the outskirts of a city and then transferred to a maglev vehicle to travel at high speed to a second city.
Improvements can also or alternatively be made in Autran carrier vehicles without changing the construction of platforms, cabins or containers and, in many cases, without significant changes in guideways. In the system as now proposed, the carrier vehicles move within a generally tubular guideway that provides weather protection and also absorbs noise. Precipitation can enter the guideway but only through a narrow slot through which the upstanding load-support posts extend. Each carrier vehicle has front and rear steerable bogies each having lower and upper steel wheels engaging lower and upper tracks within the lower and upper tracks within the guideway. The construction produces accurate wheel tracking, reliable movements through Y junctions, high traction forces when needed, safe support of loads and other advantages (For details, see www.autrancorp.com/cv/cv1)
In the future, magnetic or aerodynamic forces may be used for partial or complete support of carrier vehicles with appropriate additions to the vehicles and with guideway modifications that should be achievable at low cost and without destruction of existing guideways. Wheeled support and guidance should probably be retained in most all cases for use at low speeds and for protection in case a maglev or other support system fails. In the present Autran design, a standard type of rotating induction motor operates through a multi-speed transmission and a standard differential to drive the wheels of one bogie. I believe this arrangement has important advantages over LIM or LSM arrangements particularly as to costs. However, if desired, a LIM or LSM arrangement could be substituted without any major changes in components.
The Autran electronic modules include load modules, vehicle modules, M&C (monitoring and control) modules, section and other modules. The load modules send data to the vehicle modules including data that identifies stations at which stops are to occur. The M&C modules are positioned along the guideway for control of vehicle speed. Each M&C module senses the speed of a passing vehicle and rapidly sends data in a direct path to M&C modules behind. In response to data from M&C modules ahead, each M&C module also sends command speed data to a module of a passing vehicle to maintain a safe following distance. Certain section modules send data to M&C modules to create "phantom" vehicles ahead of certain vehicles and insure safe merging of vehicles at Y junctions. The section modules are also part of a hierarchal arrangement for sending supervisory data to M&C modules and to receive status data from M&C modules for billing and other purposes.
With communication protocols and standards designed with a consideration of future possibilities, it may be expected that for many years to come, any electronic module might be modified and improved without changing other electronic modules. However, if desirable, all electronic modules can be changed without changing other components of the system. Communication technologies are rapidly advancing but it is noted that costs are continually being reduced.
My estimates indicate that the total cost of the electronic components is a relatively small portion of the total cost of a system. (For details see www.autrancorp.com). I would be glad to respond to any questions that anyone may have. I do submit that the Autran system can be built on relatively small scale and be self-supporting and that it is designed "to be able to evolve, adapt to changing needs, and incorporate technological advances in a basically incremental fashion."
If adopted on a small scale, it could provide the basis for an evolutionary process to develop an integrated large scale network. Such a network could include, for example, PRT portions in which small passenger cabins are carried by carrier vehicles of small size and capacity but can be transferred other portions that include carrier vehicles of larger size and capacity. Such a network might also include maglev portions for high speed travel between cities, similar to those proposed by Reynolds. There are many other possibilities as well.
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Last modified: May 27, 2001