SkyTran BrainFAQ

Safety Issues

Q: Pods need seatbelts/airbags, a next stop panic button, and interior closed circuit TV (CCTV) and communications. Vehicles may not appear to need these technologically, but people unused to driverless vehicles will likely want the security of added safety features built in.

No vehicle is or can be perfectly safe, with no risk of injury or death. Safety is a main goal, and key trait, and design strategy. Maximum user safety is more important than user psychology. Suspended vehicles, narrow vehicles and track, elevated track, monorails, and magnetic levitation, have many safety traits. SkyTran adds systems to these. We intend to create the safest, or among the safest, transit systems ever built. Yet, it will likely be only 10,000 to 1,000,000 times safer than cars. Calculations reveal only so much. Safety has many variables. It is hard to know for sure without empirical data from running systems. Some team members have lost loved ones in car crashes.

Precedents, reasons:
  1) Elevators, lifts. Most people in developed lands often use, and are very used to, driverless vertical transport vehicles, so much so that few users even recognize elevators (lifts) as vehicles. Elevator users need no extra safety systems beyond the ones usually included: automatic brakes, one alarm button, one emergency voice channel in newer units. Elevator death rates are very low. But elevators move far more slowly than most driverless horizontal transport vehicles, so more safety systems are sensible.
  2) Constrained dimensionality: 1D tracks. One dimension (1D) motion is far more confined and controlled than 2D motion, with far less freedom and fewer chances for intersection or collision. Railroads are 1D systems with far lower death rates than roads and motor vehicles. Most rail deaths involve intersecting and colliding with 2D vehicles: cars, busses, trucks. Few train-train intersections occur.
  3) Isolation, control. On system tracks, only system vehicles are allowed. No exceptions. This lowers randomness, raises control.
  4) Avoid intersections via tuned track height. Principle: keep vehicles above or below problems. Elevated vehicles cannot intersect lower (or higher) vehicles, and thus have far lower collision/crash rates and risk than 2D surface vehicles, which intersect often. SkyTran pods ride 30 feet, 9 meters, above ground. Intersections and collisions are eliminated, except with birds and in very unusual conditions.
  5) Monorails. These are based on the above ideas, and are the safest form of transport ever built. In over 100 years of use, only one person has died using them www.monorails.org . Vehicles move in only 1D (one dimension), with no cross traffic, not in 2D with multiple lanes, as do most extant ground vehicles. Collisions are very rare.
  6) Suspended vehicles. Vehicles suspended under tracks can't hit items atop tracks, cutting crash risk. Some monorails use suspended vehicles. When trucks with very tall loads drive under tracks, stop using that section of track until the danger is past. This gives several extra feet of clearance.
  7) Narrow vehicles, tandem seats. Tandem seats halve collision risk. Research shows that for a given vehicle type, for the most lethal types of crashes (frontal: head-on, and nearly), collision frequency is mostly proportional to vehicle width, and collision severity is partly proportional to width. Safety is inversely proportional to width. Wider vehicles crash more often, and more fully. Width kills.
  8) Gentle shapes. Curved, high strength to weight, impact resistant forms, outside and inside, with no protrusions, such as control knobs and buttons; all control is verbal. At Cessna Aircraft, Doug Malewicki was a safety observer in windshield bird proofing impact tests in which recently anesthetized chickens were pneumatically launched into aircraft cockpits at 250 mph speeds to record, measure, and evaluate impact traits.
  9) Strong, impact resistant materials. Composites can be arranged/optimized to spread, dissipate, absorb impact forces better than homogeneous materials.
  10) Computer control. Vehicles that move under precise computer controlled speed and spacing, not under highly variable human control, as do most extant ground vehicles, should have far lower crash rates.
  11) Sensors. Vehicles, tracks, and poles can be instrumented to warn of problems.
  12) Automatic braking systems: 1/2 G electromagnetic, and 6 G auxiliary emergency mechanical, redundant brakes. It is easy to decelerate vehicles at any rate up to and beyond what humans can safely sustain. Total braking force is limited to 6 G, the same acceleration forces people pay to enjoy in some amusement park rides, to avoid harming old, sick, and infirm users. Brief, high, controlled braking forces are preferable to far higher, uncontrolled crash forces. Mildly irritated users are better than injured or dead ones. In a very severe situation, if a track section is suddenly destroyed with no warning (bomb, oversize truck), vehicles following even as close as one half second behind each other while traveling at 100 mph (a 72 feet spacing) have a high chance to stop in time. At only 6 g, a rate very tolerable to properly restrained people, you can brake from 100 mph to zero in about 55 feet. It may be hard to hold on to items, but you will be uninjured.
  13) Standard 4-point seatbelts, with interlocks. Vehicles won't move until users are safely and securely belted in, as in some amusement park rides. At least two firms sell airbag/seatbelt hybrids for aircraft: seatbelts that inflate on impact to lower force concentration on users; inflation motion is more away from users, instead of at and into them at 200 mph, as airbags do. Airbags seem unneeded in pods.
  14) Communications. Integral communication and entertainment system, with screens as an option; likely IP (Internet Protocol) based, because it is robust, redundant, and freely licensed so use is free, implementation is cheap. May use track interiors as partial microwave waveguides. It will always be easy for users to speak to others, including help. For emergencies, a voice channel is enough; CCTV (closed circuit TV) is unneeded. Pods have no buttons, all control is verbal.
  15) Options, choice. Those who are insecure about trying new things, such as SkyTran, are free to choose to travel by other means. They can wait as long as they like, even years, while braver souls benefit from faster travel and prove that it is fully safe and easy to use.

The above safety traits apply mostly to system users; users in vehicles. But, some also apply to non-system users; those outside vehicles. Elevated narrow vehicles radically improve their safety. Yearly, in the US, ground vehicles kill about 5,000 (550 child) pedestrians, injure 80,000 (30,000 child). Daily, the US slaughter of animals is shocking. Estimates are one million mammals killed a day, and countless billions of lower organisms. We can end most of this.

Q: The vehicles are magnetically levitated, so when the electricity fails, all will crash into the tracks at high speed, destroying the vehicles, tracks, and causing massive injuries and death. That means the power supply must be perfectly reliable, which is impossible. So this system can't work.

No power supply can be perfectly reliable, all of the time. All magnetic levitation vehicles need, and have, landing wheels, so that when they slow down, and stop for boarding, and then accelerate again, they do not directly contact, and scrape against, the track. Such wheels also work during power loss, at any speed.
  It is sometimes amusing when people think they have discovered an obvious showstopper flaw with a moment's thought, even though experienced experts, with advanced educations, have been perfecting a system for decades.
  In addition, any Inductrack Passive MagLev system will stay levitated due to its forward speed alone in the event of a full power outage.  The wheels will not contact the guideway  until the SkyTran pod has slowed down considerably and starts to lose the levitation strength caused by forward motion. 
 

Track Issues

Q: What track dimensions are needed for lightweight, narrow, 2-seat suspended vehicles?

About 1 x 1 ft, 30 x 30 cm, wall thickness of 1/10 inch, 2.5 millimeters, roughly square section, mildly radiused with built in torque tubes for anti-twisting stability. Thin track is possible via poles spaced closely, 30 feet, 9 meters, apart. With poles spaced farther, tracks grow heavier, deeper, more visually intrusive, and costlier. Of course, the vertical support poles would also grow larger to support the additional weight.  Dr. Richard Post of Lawrence Livermore National Laboratory, LLNL, may have a web/roll manufactured, laminated multi-ply sheet inductor geometry that can be far thinner, lower mass and cost than the current separate copper coils with ferrite inductance coils. It may allow somewhat thinner tracks.

Q: Even if vehicles go 100 mph, so what? Each time someone stops, everyone behind them must stop and wait, so non-stop travel is pointless or impossible.

No. Do vehicles filling up at gasoline stations, or exiting freeways, stop traffic? No. Why? Because such vehicles are no longer on the road, blocking it, but are off the road, doing other things, even while stopped. With offline loading and unloading, vehicles do not block traffic. Offline loading is used by many railways, and proposed for many PRT systems, including SkyTran. It is an old idea. Non-stop travel is why freeways are so useful, and why people like them. But, in many cities, congestion makes many freeways into low speed parking lots once or twice a day. In some cities, slow driving occurs for many hours a day.

Q: The vehicle/track system is planned to resist 150 mph winds. The UK rail system is seriously disabled every autumn by leaf litter (mould), despite £9.2 billion being spent recently on modernizing one line alone that promises speeds of 125 mph when done. What is the forecast reliability of SkyTran as to intense heat, heavy rain, fog, ice, snow, and leaf litter?

No transport system built yet can run in all weather. SkyTran comes closest. Reliability is a main SkyTran goal. It is immune to fog, heavy rain, and snow. It can zip over 4 meter snow drifts, or floodwaters, as easily as over clean dry paved streets; it makes no difference. Tornados and strong hurricanes/cyclones will stop SkyTran.

A strong advantage of suspended vehicles, narrow track, elevated track, monorails, and magnetic levitation, is that each lowers vehicle and track vulnerability to contamination, from precipitation (liquid, rain; frozen, snow; mixed phase, sleet), biofouling (plant, animal), or deliberate acts of vandalism or sabotage.
  The track is enclosed from most angles, with only one narrow slot in the bottom. The loaded surface is almost inaccessible, to most weather, organisms, tree branches, falling wires, or other debris. Only under rare conditions of high wind and vorticity can anything blow onto the loaded surface, only to be shed promptly. Determined tiny crawling and flying creatures can enter, though with little or no gain to them, they will leave soon, or be blown out by normal vehicle motion. Casual vandals cannot access the loaded surface. Determined vandals can, but it is far harder than in other geometries, with far less reward, and is far easier to detect by sensors. Cleaning needs are mostly eliminated via prevention. Electromagnetic suspension, propulsion, and braking (magnetic levitation, linear electric motors) do not touch surfaces, and work over even highly fouled track.
  Extremes of heat and cold need attention to material contraction/expansion, as in any other engineered system of the last two centuries.

Q: Systems in snowy areas will cost more, for heating vehicles and portals, track covers to prevent snow build-up, etc.

No. Standard vehicles have climate control, electric powered. Heaters can use resistance, small heat pumps, or another principle. Air conditioners can work as in a car. Heat pumps run in reverse are air conditioners, so one device can heat and cool. In the tropics, omit heaters.
  On-demand transport systems eliminate most need to wait for rides, except in unusual conditions. Consider car garages or carports: most people do not wait around in them before entering their cars, and most such structures are unheated. Portals are no more than covered stairs and platforms to access vehicles and tracks, so they have no doors. This is analogous to covered carports outside a house. Adding doors slows users, and raises costs. There is no need to wait in portals. They need no heat. Heating buildings adds to costs and pollution. Avoid it wherever it is unneeded.
  Time spent waiting is time wasted, forever. Waiting is waste. The purpose of transport is to move things. Users use transport to go, not to wait. Motion matters. All else is waste. Waiting is expensive; it costs time, and thus, money. The ideal transport system is all motion and no waiting. To get as near the ideal as possible, eliminate everything that does not move users. These are ideals. Reality is a bit messier. SkyTran is about practical speed and efficiency.
  Tracks are fully covered already and need no extra consideration for snow or ice. See prior entry.

Q: Systems must be assessed in resistance to vandalism, a persistent, rising, often life threatening problem in present mass transit systems.

No transport system can void all threats. Relative to extant transport systems, narrow vehicles, suspended vehicles, elevated track, low mass monorails, and magnetic levitation have many inherent physical and operational advantages to eliminate many types of vandalism, and reduce other types, and the severity of, incentives and rewards for it. Poles, tracks and vehicles can be instrumented to sense problems, and automatically notify officials of time, position, and magnitude. Serious, casual vandalism is very hard. Design for abuse.
  SkyTran team member Jerry Fass has given this issue long and deep thought. He lives and works in a neighborhood on the edge of a US inner-city, often travels in the inner-city, has friends and does volunteer work there, and sees many interesting and instructive examples of vandalism as he waits for busses, walks past barbed wire fences, nods respectfully to various watchdogs, or pauses to listen reflectively to the mournful wailing and howling of police sirens, or the creepy staccato rhythms of recreational and working gunfire on summer nights and New Year's Eve.

Q: The website doesn't detail nodes and merge/de-merge situations common in urban use. Systems must be able to fit in constricted city spaces common in UK and much of Europe, and in major conurbations in the US. Concerns about spatial needs of nodes must be addressed. The website shows how SkyTran has limited impact in visual intrusion on a straight section, yet a need exists to have an idea of what junctions look like and how they work.

All these issues are well thought out. Some will be patented and cannot be shown. Merge/de-merge is fast and simple, via thin tracks and track engaging subsystems, thin, low mass vehicles, and track-passive vehicle-active electromagnetic switching.
  Compactness is a main SkyTran goal: it is highly optimized for flexibility and tight right-of-way and installation needs. Junctions can look like two straight portals, crossed, atop each other.
  The SkyTran website is incomplete since no funds exist to advance work on it. It is done fully by Doug Malewicki in his spare time, with occasional, voluntary contributions from other people.

Q: Tracks must handle speeds of 150 mph in suburban/inter-urban use for systems to compete with trains. Systems must show clear speed/safety/accessibility advantages over all other transport modes, except long distance air travel.

Why? These are double standards, and false. Most other PRT systems fail these tests, by far larger margins than SkyTran. Yet, SkyTran can beat other systems on all such variables, and many more. Moderately detailed calculations suggest that SkyTran can easily have 150 mph cruise speeds, or even 250 mph, with subtle modifications.
  Yet, higher speed is unneeded to compete with trains, or aircraft, at regional ranges. For two cities, departure and destination, with full SkyTran grids, linked by one SkyTran track, point-to-point trip times can beat jet aircraft for trips of 400 miles at 100 mph intercity speed, 600 miles at 150 mph intercity speed. The long times needed to get to and from, and to enter and exit, airports greatly lowers the average speed of aircraft trips.
  This makes SkyTran a useful transport system of regional scope in large nations, and national scope in small nations. For longer trips, with extant technology, aircraft make more sense and are more efficient: because ground vehicles move at low altitude in denser air, aircraft move at high altitude in thinner air.
  SkyTran safety and accessibility can be equal to, or better than, all alternatives, unless badly written laws cripple efforts to optimize such traits, and force suboptimization.

Good luck.
Good bye.
Jerry Fass

SkyTran: faster, cheaper, safer, leaner, cleaner, greener!
A lean, lightweight, flexible, heavy duty, packet switching network that moves people.
http://www.skytran.net/

I just decided to paste in a version of that average speed spreadsheet with inputs for your route conditions (you can put in the exact parameters that the 300 mph people are claiming into our AVERAGE SPEED CALCULATOR in order to see more precise travel time performance comparisons).

The real difference between SkyTran personalized transit and any old-fashioned form of GROUP transit is all that stopping and starting. The fact that 40 people want off at station #2 and 45 people want on at that same station means you HAVE to stop at each and every station along the route.  That costs you time and that lost time kills your AVERAGE speed!  SkyTran is little two seat pods - would be crazy to stop and start at every station along your route.  You go straight to your final destination station NON-STOP!   We have been talking 150 mph NON-STOP intercity!  Half the speed of your 300 mph group carrying train and we can get there as quick!  (We are also talking to an amusement park group about a zero to 300 mph to zero ride - so the technology lends itself to that. High speeds are just a terrible consumer of energy to move objects fast in dense sea level air).

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