Personal travel and transportation of goods are the cornerstone of modernization and foster both cooperative and competitive efforts in a wide diversity of new markets hungry in one area for what is common in another. The development of transportation technology began with the carrying of large burdens by hand, progressing through the domestication of beasts of burden, and ultimately arriving at the modern use of mechanical systems to aid the transportation of people, livestock, and goods across increasing spans of distance in decreasing amounts of time; however, current transportation technology is nearing the saturation point and new innovative methods are needed in order to see to the needs of the people in the new millennium.
Current overland transportation technologies ranked by rapidity of transit:
- Air Travel
- Vehicular Transit
- Rail Travel
- Livestock Transportation
Air travel is the most rapid for short (50 miles) to medium (300 miles) distance travel or transport. Increased demands on the infrastructure of this industry create delays of up to 20 minutes, which are considered common in several of the major hub airports. These extreme delays cause scheduling conflicts in later flights and difficulties for travelers relying on connecting flights, while lesser delays are commonly reported both domestically and abroad.
Expanding air travel capability can be difficult in urban areas for many reasons: public outcry against greater noise levels, concerns over safety precautions when taking off or landing within densely-populated areas, scheduling and logistics problems encountered when attempting to add additional levels of holding patterns to already-crowded airspace, and the increased demands on the facilities, personnel, and vehicles in use by this industry. Aging is also a factor, as the stresses placed upon the vehicles and runways during takeoff and landing procedures, as well as such variables as weather conditions, continue to degrade the existing equipment and facilities to the point where wide-scale replacement and renovation is becoming necessary.
Vehicular transit is also widely used, both in terms of personal automobiles and medium-haul cargo transportation via trucking. Examination of the degradation of the widely-used thoroughfares such as IH-35 indicates that this form of transportation is not without significant cost in terms of the upkeep required in order to maintain a safe route for transport. Additional studies now indicate that the petroleum byproducts may also be contributing to long-term environmental degradation both through damage to the ozone barrier as well as through the addition of the so-called greenhouse gasses. Added to this are the potential hazards inherent in the event of an accident within an urban setting involving toxic or damaging cargo, and the increasing short-distance demands which have mandated the creation of 18-lane highways in heavily-populated areas, both of which restrict the maximum volume of cargo which can be transported by current vehicular methods.
Livestock transportation, though still utilized in some areas, is by its very nature of a low volume and thus does not offer significant opportunity to provide for the expected increase in demand for travel and transportation needs in the near future. Other factors such as the inherent problems found when working with biological, as opposed to mechanical, systems such as disease, injury, and susceptibility to environment add to the reduce-capacity of this type of technology.
Of the primary forms of transportation, railed travel currently handles the greatest volume of overland cargo transit, and offers the greatest opportunity for development to meet the increasing transportation needs. Railed travel also offers reduced opportunity for accident, provided a clear right-of-way is maintained. Additionally, railed transportation is generally less environmentally-invasive than other forms of travel, both in terms of exhaust output and noise levels through urban areas. Rail transportation generally suffers less catastrophic results than air travel or vehicular transportation in the event of significant equipment failure due to its dedicated ground-level right-of-way.
The current state of the art in railed transportation has finally reached speeds which allow railed transit to successfully compete with airlines for short-to-medium range travel, both in terms of personal travel as well as medium-weight freight transport. The French Train a Grande Vitesse (TGV) is the most-successful example of this form of transportation currently in widescale use. Several portions of the US rail system may be able to accept this form of technology with only minor upgrades in the short-term, allowing long-term development of more exotic forms of transport which do not suffer the effects of wear and other types of use-related degradation of facilities.
Figure 1: Conceptualization of Conventional rail technology.
Conventional rail transportation is relatively unchanged from the early steam-driven engines to the modern diesel-electric titans that haul the majority of the overland-carried goods throughout the US. The engine, now a diesel-powered generator driving massive electric turbines, transfers power to the wheels, which in turn rest atop tracks laid in carefully graded rights-of-way. (See Figure 1.) As an example of how many facets of this technology remain unchanged, slippage of the wheels is still reduced by the simple deposition of sand on the metal tracks below the engine.
Other forms of railed transportation are being developed to operate at speeds approaching those of conventional air travel, while maintaining the benefits of low-altitude (ground-level) travel including greater safety. These will be discussed in the next section.
In order to increase the speed which the vehicle may travel, as well as reduce the wear and degradation of performance which accompanies any form of mechanical contact, the ‘new breed’ of railed transportation no longer relies upon its wheels save at low velocities. These new designs literally ‘fly’ along their guideways, propelled by the electromotive force generated by alternating-current magnets embedded in the guideway reacting with opposing magnets within the vehicle itself. These designs are in general also supported by additional magnets either above or below their guideways, providing a rapid rate of travel without the need for direct mechanical contact with the guideway.
A variety of options have been considered and discarded since the original discovery of this form of travel at Stanford University. The majority of the designs nearing commercial viability rely on one of two basic formats: either attractive levitation or repulsive levitation of the vehicle. Air-cushion designs using ducted fans to force air beneath inflatable skirts for levitation, relying on their electromagnetic systems for propulsion alone, were attempted both in the US and Japan in the late 1960′s as well as early 1970′s and attained speeds in excess of 260 miles-per-hour in test runs; however, advances in air-traffic control systems allowing increased density of commercial air travel ended the research into such systems as the US Tracked Air Cushion Vehicle (TACV) and the early Japanese MLU-series vehicles.
Figure 2: Conceptualization of Attractive-levitant systems.
Attractive-levitant systems (see Figure 2) such as the German Transrapid TR-series utilize a ‘wrap-around’ design which relies on the attractive force between electromagnets situated in the guiderail to draw upwards the electromagnets located in the vehicle, as well as provide forward motive force. This format requires very close tolerances in guiderail construction, for the air-gap is very small between the track and vehicle’s magnets in order to optimize the attractive force and reduce power consumption. A short-run track of this type is currently being tested in Orlando, Florida, using the German-based Transrapid TR-07 design.
Repulsive-levitant systems (see Figure 3) such as the Japanese MLU-series use the repulsive force exerted by powerful electromagnets in the guideway upon cooled superconductive magnets in the vehicle’s base in order to support the vehicle within its channel-guideway. Additional magnets in the sides of the vehicle are deflected by electromagnets in the guideway in order to provide guidance and propulsion. This configuration requires a great deal of constant automated adjustment in order to maintain proper positioning. Test tracks using this technology are currently in use at several development sites in Japan.
Figure 3: Conceptualization of Repulsive-levitant systems.
Under the National Maglev Initiative (NMI) and other items of legislation aimed at keeping the US at the forefront of developing technology, the Office of Technology Assessment (OTA) currently recognizes four US-based development groups attempting to create American High-Speed Railed Vehicle (HSRV) designs for domestic use. Bechtel, Foster-Miller, and Grumman are all developing variations of either the Attractant-levitant or Repulsive-levitant technologies.
Figure 4: Conceptualization of US Magneplane design.
US Magneplane provides the fourth primary contender for a US-sponsored design. (see Figure 4) This is a form of repulsive-levitant vehicle that remains suspended atop its guideway while being propelled forward by a set of cooled superconducting magnets located in the curved base of the vehicle reacting with the aluminum guiderail. It is dynamically stabilized, tilting through curves without the need of specialized equipment, while remaining supported atop the rigid guideway. Only scale versions of this technology are currently under test, although a larger version is planned.
These designs suffer from the need for either high-capacity onboard power-storage systems such as those used by the German Transrapid TR-series vehicles, or exotic cooling systems required in order to maintain the superconductive magnets in systems such as the Japanese MLU-series. Quenching, or the spontaneous loss of Superconductivity, is still a concern for these systems, and a catastrophic loss of power to either the onboard magnets or guideway levitant mechanisms will result in the vehicle dropping to the track at travel-speed. One of the Japanese MLU-series vehicles was damaged during such a test. Friction caused the vehicle to catch fire and the response was further hampered by the superconductive magnets’ attraction to the rescue personnel’s equipment when approaching too near while attempting to fight the flames.
An additional consideration in all of the above designs is that of the still-unknown effects of long-term exposure to strong electromagnetic fields on biological organisms. The repulsive-levitant systems exhibit the strongest magnetic field strength within the passenger compartment due to the close proximity of the superconducting magnets in the floor and walls of the vehicle, though the attractive-levitant systems in the German Transrapid system have been measured at over 50 Gauss within inches of the passenger compartment, with lesser measurements within the compartment itself. Measurements of secondary EM and RF fields were not specified, save that eddy currents in the vehicle’s body in both formats require special isolation considerations for all onboard electrical systems. These technologies are at best nearing marginal commercial viability, while many remain inefficient power-hungry testbeds for later development; meanwhile, other formats still remain untested.
The dynamic-lift air-cushion vehicles used in the TACV trials demonstrated that a pneumatic-levitant system propelled by electromagnetic force could attain speeds rivaling those of current airplanes. Any design requiring onboard fuel for the engines which inflate the pneumatic skirts suffers the same limitations as the other Maglev designs currently being considered in that a large portion of the vehicle must be dedicated to supportive equipment and fuel storage, as well as limiting the maximum operating range of the vehicle to that which the fuel or coolant capacity can support (allowing appropriate margins for safety).
Figure 5a and b: Conceptualization of a wing-in-ground-effect design for a guideway-supported vehicle.
An alternate design option utilizes pneumatic-support in a static-lift system using the wing-in-ground-effect designs such as the Russian Ekranoplane and the aquatic Flarecraft. In this format (see Figures 5a & b), a fixed-wing vehicle is accelerated by an electromagnetic system in order to pass close above the ground (in this case, above the guideway), creating a buildup of high-pressure air beneath the plenum which in turn provides support of the vehicle without requiring onboard lift-generating engines or inflated skirts which introduce additional drag on the system at higher operating speeds.
Figure 6: Location of magnets in track and vehicle.
This design places the vehicle’s onboard magnets as far from the passenger compartment possible, locating permanent magnets in the pylons at the ends of the winglet array. (See Figure 6.) As the electromotive force is not required to hold the vehicle clear of its track, instead functioning merely to accelerate the vehicle along its path, the strength of the electromagnets set into the guideway should be of a lower order than that found in other current designs.
Figure 7: Out-wheels on ramp.
The current Maglev designs require a fixed-path course or elaborate switching systems involving redirecting several hundred yards of track in order to change tracks or exit the main line for disembarkation or servicing. The Magnetically-Propelled Pneumatically-Levitated (MPPL) design merely extends its sponsons and their guide wheels to the ‘outward’ position (see Figure 7), and then rolls up a ramp using the forward speed of the vehicle in order to provide additional lift during this maneuver.
Figure 8: Normal progress past ramp (foreshortened for illustration, not to scale).
Meanwhile, all other vehicles following on the line will have experienced no interruption in their own progress (see Figure 8), since they will pass beneath the disembarking vehicles in the station above without the need to slow or alter course. By activating the magnets only in those sections of guideway in-use, the system can be made more efficient.
Figure 9: Re-entering guideway via ramp (foreshortened for illustration, not to scale).
After processing passengers and cargo at the station waypoints, the vehicle then merely descends along a ramp to re-enter normal progress during the next opening. (See Figure 9.) Again, no interruption of service is required, and the number of mechanical systems necessary in order to enact this is significantly lower than in any of the other current designs.
Due to nature of its design, the MPPL system enjoys lower EM exposure levels for its passengers, requires less precision in tolerencing its guideway (as its air-gap is dynamically stabilized in flight without requiring elaborate positioning and stabilizing systems), requires a simplified track-switching and docking system with a reduced parts count, utilizes existing technologies in both the creation and maintenance of this system, and enjoys protection against damage due to sudden power-loss, as the system will remain supported aerodynamically until the vehicle slows to a speed which its wheels can easily handle, rather than dropping forcefully at travel speed as all full-levitant systems may in the worst case.
Figure 10: Conceptualization of reflected pressure waves from passage of vehicle being used to recover acoustic energy and decrease following low-pressure zone to increase efficiency.
A number of additional features may render the system more efficient, including such considerations as regenerative braking, texturing the vehicle’s surface in order to improve laminar flow. Even such features as placing the system in a tunnel or culvert with a fixed width, so that the vehicle’s speed may be adjusted according to altitude, temperature, barometric pressure, and humidity levels so as to cause the reflected pressure waves generated by the vehicle’s passage to coincide with the rear of the vehicle (see Figure 10), creating a standing wave of higher pressure to offset the low-pressure following airmass may thereby reduce system energy loss overall.
Figure 11a & b: A variety of wing-designs and textures may be used to optimize the laminar flow over and around the vehicle.
Additional testing is required to determine the optimum angle of attack and wing structure for the foreshortened wings (see Figures 11a & b), as well as optimization of the vehicle’s fuselage for a reduced drag coefficient. A variable angle of attack for elevated preceding winglets may allow greater efficiency in varying environmental conditions and lower speeds, either via automated control or manual piloting of the vehicle.
The original wood and paper model disintegrated at less than 90 mph due to environmental conditions, yet proved the basic design functional. A slight tendency to dip the bow was also noted at higher speeds. True aerodynamic optimization was minimal on the prototype due to the crudity of equipment accessible for its manufacture. As a result, the renderings are intended not to illustrate the precise external configuration but rather merely to illustrate the concepts presented herein.
I have since refined the plenum design somewhat to allow for variable-angle wing modules capable of providing lift at low speeds and closing to form a sealed plenum volume for sustained flight. The addition of small canard-style wings at the bow and an elevated tail lifting surface stabilized pitching and dipping at scale speeds. Further refinement of the sponsons allows this design to fold its wings upwards along the vehicle body to facilitate light-rail use over conventional railways using auxilliary electric motors and onboard batteries to accomodate transitional use as WIG-levitant tracks are built up.
ORIGINAL POST: Pre-1998 on Geocities, later on my http://khausman.wolf-song.com/ site. Content updated to reflect recent improvements to plenum, sponsons and lifting surfaces in May of 2012.