HORSESAILING AND ZERO GRAVITY TRAINS
Copyright © 1999 by Bill Drake
HORSESAILING - THE GENESIS of ZGT
I was driving up Interstate 35 in Texas with the window open and the warm August air in my face, and began imagining the countryside I was now passing through so comfortably and swiftly in my car from the point of view of someone travelling by horseback a hundred years ago.
This evening something was different about the light, and the valleys and hills of Central Texas took on a special appeal. In my fantasy I was riding my horse in the 1890s, tired from my long day's journey of fifty miles or so, wishing that on such an evening my horse had wings and could fly me all the way home. I wasn't dreaming of flying like a bird through the sky, rather of leaping from hilltop to hilltop on horseback, taking the countryside with half mile glides, arriving at my home a hundred miles away well before bedtime and having great fun to boot.
Too bad, I mused, that the days of horseback travel that settled this country didn't coincide with today's parasailing and hang-gliding technology. Because if they had, surely some inventive cowboy would have had the idea of hooking up a horse to a wing and gone leaping off a nearby cliff to try it out. So much for the Wright brothers. Horsesailing would have been born not as a sport but as a whole new way to move across vast territories quickly and efficiently with the distinct advantage of having a regular bird's eye view. Then I thought - what if that wing was not just an aerodynamic shape, but a helium-filled shape that not only provided gliding capability but also provided lift? What if the weight of the horse and rider could be neutralized completely by a helium balloon in the shape of a wing?
I amused myself with the visions invoked by this idea for quite a while. I saw Genghis Khan and his Mongols cruising 12th Century European skies and realized how horsesailing could have changed history. I envisioned Moorish cavalry sailing across the Straits of Gibralter on winged horses, and I saw Roman chariots dominating the skies of all earth. I saw a very different kind of wagon train settling the American west, with Cowboy & Indian battles among the clouds on horseback. I imagined modern horsesailers bouncing off the hills around me, leaping the utility wires, hot dogging across the countryside, and had visions of cops driving shiny four-horse sailing rigs, chasing a nation of suddenly liberated airborne hot dogs who could scatter in any direction, no longer constrained by roads.
The more this went on the more I began to think - why not? How big would a helium balloon shaped like a gliding wing have to be? How many cubic meters of gas would it actually take to neutralize 90% of the weight of a combined horse, rider and steering/navigation rig? All the way home I contemplated my fantasy with increasing interest as evening turned into night.
The next day a trip to the library told me that a helium-inflated wing-shaped rig to neutralize one ton of rider, horse & balloon and controls combined at sea level would have to be less than the size of a conventional truck semi-trailer. I began to think about a weight-neutralized wing-shaped helium balloon tethered by wires to a lightweight console-saddle. The attitude, pitch and yaw of the inflated wing would be controlled by lightweight high speed computer-controlled winches mounted on the saddle-console, taking in or letting out wire, allowing the rider to control the direction of gliding flight with a simple joystick. It's possible that as models evolved the weight of a small solar electric array might be included in the technology onboard a horsesailer, in which case you could have an electric motor driving a propeller for extended flight and powering communications and navigation equipment.
I live in horse country, and I've noticed that there's a special class of horses who seem like perpetual adolescent humans - strong, boundless energy, self-centered, love showing off, like to be ahead of everybody, still too stupid to be afraid when they ought to be, ready for anything. These animals are perfectly suited by temperament to become horsesailers.
I began to imagine how one would train a horse to become Pegasus. Surely it would start by attaching progressively larger helium-filled balloons to specially selected colts at each stage of their development, on a schedule which didn't interfere with their natural development but which allowed them to learn the skills of takeoff leaps, running landings, and the other new techniques required of an animal being trained to run in half mile strides. Then at a certain point they would begin to carry a human rider and to mature into a full-grown Pegasus.
I began to imagine what horsesailing could mean around the world. It might become a new sport, one especially suited to the western United States, the great open spaces of Australia, Asia, and Latin America and all the other still vast, still unsettled areas of the world. Early settlers rode painfully and slowly across these lands on horseback, oxback, and camelback. One of the reasons these places remain so sparsely settled even today is because they are so vast they are inaccessible without real effort and cost. Only a hardy few today go on horseback pack trips into these areas of wilderness for recreation, and almost none trek across the great heartlands of the continents, the prairies and steppes.
Horsesailing could change all that. If you could cover five hundred miles in a day on horseback, leaping from hilltop to hilltop, across wide ravines and rivers, taking a hundred mile detour in an hour or so, racing up the side of tall hills in a few bounds and leaping from the summit of a mountain into the clouds - if all this could be done easily and cost-effectively, the vast empty plains and the inaccessible mountains and valleys of earth could change forever.
With a horse trained to relax and enjoy the view while sailing, and to hit the ground running when the time comes, and with a lightweight airbag system which could be deployed if in the pilot's judgement there's a hard landing coming up, the horsesailer would be equipped to master almost any terrain. If also equipped with a satellite-based communications system, a horsesailer could have instantaneous communications, whether they were stranded in the middle of the Canadian Rockies with a broken rig, or simply calling a city a hundred miles ahead to make dinner reservations for two hours from now.
I began to imagine the natural communities of the plains and mountains as villages springing to life as resting stops and accommodations for touring horsesailers. I imagined horsesailing the American west, the Argentine Pampas, the remote valleys and plains of the Asian Steppes. I saw the towns of these regions becoming hubs for horsesailing expeditions for visitors from around the world, and the outlying regions developing tourism resources around areas of previously remote natural resources like springs, hot water spas, and other beautiful, remote garden spots in the wilderness.
I imagined the ranching options possible with horsesailing technology, and the economic impact that such a technology would have on forestry and resource exploration. I saw horsesailing as a new industry for horse-breeders, for resorts, for transportation. I imagined the fuel savings possible in transporting goods in a weight-neutralized trailer behind a team of flying horses.
I saw all of these things as if in a vision of another time and place, and concluded that while I might never go horsesailing in this life, there is still a lot of flying to be done in other ways. I still think as I drive in the evenings through the Texas hill country where I now live how nice it would be to be going home on the back of a horse through those sunset dazzled clouds. And then I think - how wonderful it is just to be going home, even in my earthbound vehicle, and I am truly grateful.
FROM HORSESAILING TO ZERO GRAVITY TRAINS
I first dreamed of horsesailing in 1990, and for several years afterwards I would find myself thinking of the invention in a "why not" frame of mind. Then one day as I was reading a newspaper story on the new regional light rail system being proposed at a cost of billions of dollars in Texas, I was struck by a connection between horsesailing and a potential new approach to train transportation.
Transporting people and goods in an efficient, cost-effective and environmentally sound manner is proving difficult, costly and sometimes impossible with current technology in communities throughout the world. Current efforts to deal with increasing auto and truck traffic are limited to better, wider roads and various regulatory and incentive plans but most research shows these approaches are failing. Many believe that light rail or monorail are viable answers, but such development is often delayed, constrained or blocked by cost, political and property issues.
I began to envision a system using existing technology in a new way to produce high speed, ultra-low impact, community-owned transportation systems that will avoid conflict with private land interests and provide world class transportation for any community. I called the system the Zero Gravity Train - ZGT.
BACKGROUND & DESCRIPTION
The primary technical, financial & environmental challenge to building new rail-based transportation systems is that rail requires an extensive and expensive physical infrastructure on the ground. Even the latest high-technology trains follow the established model of railcars pulled by an engine running on rails. Urban light rail systems are being designed to make the best of the existing situation but do nothing to break truly new ground. Magnetic Levitation trains do lift the train off the rail, but the MagLev railbed and indeed the whole system requires even heavier and more expensive tracks than conventional rails and beds and so is very limited in terms of cost and where it can be built. The monorail concept tried to break the earth-bound pattern by hanging the engine and cars from an overhead rail, but such systems still require heavy towers to carry the weight of the system and thus are expensive and very restricted in their scope.
I began to see a completely different approach to railway transportation created by marrying the concepts of dirigible and railcar. Just as I see horsesailing based on a helium-filled parasailing wing, I envision a transportation system composed of helium-filled ZGT pods that are suspended virtually weightlessly between guide/power wires strung almost invisibly along public lands on either side of existing roadways, old railroad right-of-ways, and other existing traffic paths. I envision individual ZGT cars made of a molded lightweight composite shell with an inflatable molded interior providing seating and other interior features for perhaps 20-30 people. The interior of the ZGT car - the seats, aisles, windows and other features - would simply be reinforced molded elements of the airbag, which might made from the same material as the Mars Rover impact airbag.
The easiest way to envision the ZGT system is to see it as a system of small helium-filled aerodynamic pods that never fly free, but instead glide along in a controlled float, tethered between a set of power and guidance wires that are suspended from low-profile shock-absorbing pylons, similar to those carrying ski lift lines or power lines but smaller, cheaper, and with lower environmental impact.
Individual ZGT pods would be powered along the guide lines by lightweight, high speed electric tractor units attached to rigid outer shell plates of the pod. With the pod's weight and that of the passenger or cargo load neutralized by the helium used to inflate the passenger and lifting structures, these ZGT cars would float between the power and guide wires rather than hanging from them. With an aerodynamic shape, gyroscopic stabilization, and a stubby set of computer-controlled fins to maintain stability in all kinds of winds, such a zero-weight craft could be suspended between three wires and propelled by an electric tractor unit at significant speeds with relatively small and environmentally friendly footprint for the system towers. There would be strong stresses on the system under certain kinds of adverse wind load conditions, but I believe that the ZGT design can compensate for most adverse wind loads without stressing the support systems to the point that they must be visually intrusive due to structural strength requirements.
ZGT lines can run alongside virtually any existing roadway, which means that a city can construct an extensive network of lines serving all neighborhoods with little or no disruption during the construction phase - far less than re-surfacing an existing road, for example. Installation of a ZGT system with its towers and wires will be no more disruptive than installation of telephone or light poles.
I can also see the use of ZGT to open vast areas of back country to compatible recreational use without the need for vehicles and roads for access. For example, I envision ZGT systems running along the walls of great canyons like Glenwood Canyon in the Colorado Rockies, or over the great Alpine mountain passes, mounted 500'-1000' up the canyon walls with ZGT pods gliding along guide wires strung from almost invisible towers that are literally screwed into the rock face.
I've calculated that ZGT cars inflated with helium sufficient to negate the weight of 30 adult passengers and a combined carbon filament/molded airbag structure would require the equivalent of a cylinder 40 meters X 20 meters at 2500 meters altitude. ZGT cars used in mountainous terrain will have to accommodate changes in the size of the airbag, and therefore the ZGT car itself, as altitude changes. This can be accomplished by constructing the car of overlapping exterior panels that allow expansion and contraction of the gas bag shell while maintaining the shape and integrity of the ZGT passenger unit.
SYSTEM COSTS
The true cost of the envisioned system remains to be calculated - but there are good rules of thumb available.
The ZGT shell, tractor units, controls and instrumentation, and airbag with the molded-in passenger/cargo sections, seating, aisles, and bins would be roughly the same size and dimension as a 737 fuselage, minus wings, tail, cockpit etc. However, since the entire interior is a simple set of molded benches and seats, and since the structure will never have to fly, the cost will no doubt be far less. I believe a cost per pod of $500,000 each is very realistic.
The cost of individual ZGT towers and lines almost certainly won't exceed the cost of putting in a set of high energy electric lines and towers along the same route. Since the ZGT lines will be much lighter than power cables, the spacing of ZGT towers will be far more economical than for a power system. In fact it's possible that ZGT lines could be retrofitted to existing power line towers, providing a new source of revenues for power companies and lowering the cost of installation of ZGT systems for both urban and rural areas. Nevertheless, let's assume we have to start from scratch and set the construction cost per tower at $1 million and the spacing at 0.5 miles between towers. Then let's add 25% to the tower cost for instrumentation etc.
With these two calculations in hand, we can calculate roughly what a system to serve a given area would cost.
For a system with 200 miles of line I estimate a network of 400 towers. To serve the system's trasportation demand I estimate a need for 200 ZGT pods,or one pod every 1/2 mile. This implies a total installed cost for towers, pods and instrumentation of $400mm + $100mm = $500mm.
Development costs for a project to demonstrate the viability of such a system would be minimized by adapting existing technology from the electric power and ski lift industries, and from the aircraft, dirigible, and recreational aircraft industries. For example, lightweight high speed tractor units developed by NASA can be attached the reinforced shell will provide smooth power for individual and trained ZGT pods, and the ZGT pod's stability can be controlled by instrumentation and control surfaces adapted directly from existing flight control technology. A ZGT airbag made from the same materials as the Mars Rover airbag would provide excellent protection to passengers in the event of a ZGT accident in which the ZGT pod fell to the ground.
ENVIRONMENTAL & POLITICAL ISSUES
With the exception of aircraft all transportation systems must have a footprint, and it can be argued that aircraft require airfields and therefore do have a footprint. Roads and rails have an obvious footprint, but even overhead monorail requires a substantial footprint for the weight bearing towers. Even proposed systems like MagLev depend on an extensive footprint. All these systems also depend on having access to a continuous strip of expensive and often disputed land.
The proposed ZGT system features towers which bear almost no weight and which can be installed without disruption to the environment. This means that when the question of bringing the ZGT system across cities and neighborhoods the argument can be made that the system will be far less impact than a power line of comparable length and configuration, and exponentially less than the construction of new highways - America's urban nightmare.
Computer controlled ZGT pods would move quietly and pollution free just above the existing system of roads, picking up and dropping off passengers at stations no larger than a conventional bus stop kiosk. A ZGT system could be easily and simply designed to interface with existing public transportation systems like bus and commuter rail lines, since the ZGT system can access spaces like bus stops and train stations from above, requiring only the addition of safe, stable stairs from the ZGT exit platform to ground level. In other words, installation of an urban ZGT system would require no new land and no new facilities. It would use near-ground airspace and would not intrude on any existing infrastructure element or system. Installation of a community-wide ZGT system would cost far less than even a few miles of urban interstate construction, and could be in place within a very short time, relative to any other form of transportation infrastructure project.
The ZGT towers can not only follow existing roadways, with little more disruption than would be involved in installing new highway lights, they can also snake efficiently and cost-effectively through canyons and across gorges where a conventional light rail system would be prohibitively costly and technically difficult. This means that cities built around dramatic terrain like Denver, Portland, Austin, or San Francisco can install ZGT systems serving the both the urban community and the nearby communities where people love to live but where the commute by road is difficult and where conventional rail is prohibitively expensive.
Since there is significant precedent for allowing the construction of both ski lift and power line pylons on public lands, including national forest land, I envision the ZGT system utilizing cable towers placed at strategic points on the mountainsides throughout the American West with connections to towns along the way. Again, if power line towers can be retrofitted to accommodate ZGT lines, this process could be radically simplified.
In mountainous terrain I envision wire-carrying tower structures shaped like oversized shock absorbers, which can be prefabricated and installed by bolts into existing rock faces with almost zero environmental disruption. Most of the load which these towers will have to absorb will be intermittent, occurring under adverse wind conditions, and will occur when individual pods are blown off course up to the limits of the guide/power cables and are unable to maintain their neutral load on the system through the use of their aerodynamic control surfaces.
In places like Aspen/Glenwood Springs or the Salt Lake City area this kind of system could be operated virtually out of sight except for the ZGT cars themselves floating up and down the valleys - incidentally giving their passengers a great ride. The supporting structures would be no more intrusive than a ski lift or power line, and the environmental balance would far more favorable since the operation of the ZGT system would replace significant amounts of land traffic in these sensitive mountain valleys with zero-emission ZGT transportation.
Floating ZGT towers would allow lines to cross both small and large bodies of water like lakes, rivers and ocean harbors and inlets. Floating towers would not have to maintain precise alignment with each other, which would make engineering and construction of water-crossing ZGT systems relatively straightforward and far less costly than water-crossing structures like bridges and rail trestles that require fixed platforms. These same system attributes might also allow construction of low cost ZGT systems serving offshore oil & gas platforms or providing passenger & cargo service between remote islands. I believe that the ZGT concept has such a small impact on the environment that systems can be economically constructed to take people into remote recreational areas for low-impact activities like walking, skiing, and camping.
On a national level, nations that have invested heavily in their transportation infrastructure will find that the ZGT concept will enable them to leverage their investments, and those that are still in the early stages of development have a great opportunity to install a fast & efficient people-moving network at far less cost and far lower environmental impact than would be the case with conventional rail technology. With conventional rail systems compromises between access and cost have to be made throughout the system, whereas with a ZGT system it becomes economical to serve virtually any size urban neighborhood as well as a large network of small outlying towns.
Instead of requiring a regional coalition to build a rail system, individual communities can afford to build their own ZGT systems, with regional or national responsibilities limited to assuring a smooth interconnect between the systems. This means that resort communities can build one kind of ZGT system and cities another, while ranching and farming communities build yet a third - each tailored to the needs of the communities they serve.
Regional ZGT - The Texas Hill Country Example
The Texas Hill Country is an ideal environment for a ZGT network, and will serve as an example of what can be envisioned for almost any region in the world. The Hill Country is an uplifted, highly eroded 20,000 square mile region in Central Texas lying between the Great Plains on the north and the Chihuahua-Sonora Desert on the south. It is an oasis of green river valleys, dramatic cliffs and hills, hundreds of both working and recreational ranches, dozens of small towns and two major cities, and all this is served largely by a network of two-lane state and county roads. Several major highways also transect the region, but there is no conventional passenger rail except between Austin and San Antonio on the eastern/southern rim.
Small highly dispersed population centers and beautiful but difficult terrain along with nearly universal private property ownership make the likelihood of future rail service to the Hill Country unlikely, yet the benefits of such service are indisputable. With already severe population pressures increasing in Austin and San Antonio large numbers of people are moving further into the Hill Country to find living room, and the small communities of the region are beginning to feel the impact of these new residents. Without access to low cost, efficient transportation there are severe limits to the economic development potential of these small communities, yet they will predictably have to support steadily increasing numbers of well-off urban refugees.
In this context one can imagine a ZGT network connecting every community in the Hill Country with a seamless web of lightweight ZGT towers and guidelines strung along existing rights-of-way for roads, highways and power lines. The system would run silently and pollution-free, with the only intrusion on the serenity of the Hill Country being the steady flow of ZGT pods along their guidelines. The ZGT system could go where roads cannot, following power line paths across ridges to dramatically shorten distances between communities compared with ground-based travel. People living in Johnson City or Kerrville could easily and economically commute to work in Austin and San Antonio. Families from Austin could wisk away in a few hours to their cabin on the Frio for a weekend, while families from Utopia could just as easily jump into the city for an evening and be home by ZGT before midnight. San Saba ranchers and their wives could run into Austin for lunch and a bit of shopping, and children from Lampasas could attend schools anywhere in San Antonio or Austin they might like.
Then of course, there's the matter of the view. There would be a dramatic difference in the views available for passengers in a ZGT pod compared with a conventional train, bus or automobile, which might make commuting almost a pleasure. Anyone who has ever ridden in a old-style passenger train will know what I mean when I say that every seat in a ZGT would be like the best seat in the dome of the observation car - times a hundred! Even in cities the view would be radically different and much more interesting than street-level scenery, while in the suburbs and near countryside passengers will be seeing more greenery than rooftops.
This kind of two-way access would create a steady increase in the demand for skilled labor, housing, recreation & dining, and other goods and services, and would increase both business opportunities and tax revenues within even the smallest Hill Country communities. Retirement communities could take advantage of the open spaces and healthy environment of the Hill Country since professional staff could easily live in Austin or San Antonio and commute economically and quickly to work in Gillespie or San Saba County by regional ZGT.
Recreational sports of all kinds, from fishing and bow hunting to mineral hunting and bird watching would flourish, while tourism would expand exponentially with the ability to explore this beautiful countryside from an aerial vantage point. Imagine a visiting tourist couple able to stay at a first class hotel in Austin, run down to San Antonio for a Mexican breakfast, then run up to Fredricksburg for some morning shopping and zip over to Marble Falls for lunch. After lunch they might head up to San Saba to pick up some fresh Pecans and explore the town, then down to Hunt for a mid-afternoon float on the Guadalupe, and finally back to Austin for cocktails with friends at 6 before heading for dinner out on Lake Travis at 8. The next day they might head out to Mason for an all-day trail ride, stopping in Kerrville for dinner on their way back to Austin that evening.
An urban ZGT network may hold promise for both Austin and San Antonio. Expansion of the existing road system in Austin is particularly difficult due to a combination of population growth and the terrain of highly eroded limestone hills and valleys. San Antonio's problem is almost the opposite of Austin's, which is to manage virtually unlimited space for sprawl.
Since most of the main roads in and around Austin follow the valley/canyon floors and natural erosion features on the hillsides, there is no room to expand the number of lanes because of residential and business development right up to the roadside. For the same reason there is no room for a light rail system - even a monorail system is infeasible except for a few major corridors- certainly nothing serving the neighborhoods. Yet, the hilly terrain in the Austin area is ideal for design of a ZGT network.
San Antonio's answer to sprawl has been to build more and more main roads and highways, which of course has enabled more sprawl. With all of the Hill Country on the North and West of the city, imagine the relief that could occur if people could commute easily, quickly, silently and pollution-free into San Antonio from anywhere within a 100 mile radius.
Every city has its uniqueness and there's no pretension that the ZGT concept can be applied everywhere, but if there is anything to the idea it seem to have a wide range of applications in urban environments worldwide. Cities everywhere are facing the same crisis in moving people, and the conflict between private and public transportation interests is escalating in many places.
In Conclusion
There is no conclusion - only an idea. That's a beginning, not a conclusion. I certainly can't build a ZGT system, but I'm certain it can be built. I'm neither engineer nor artist, and readily concede the graphics used to illustrate this idea are hokey, but if you get the point they've done their job. I hope you've enjoyed this quirky vision - I certainly have since that August evening when I first had this dream, a long way from home.
