by John Stegmann

Capsi is designed to overcome many of the limitations and drawbacks associated with existing public and private transport systems in cities. While Capsi has much in common with other new concepts, it has some novel and attractive features, such as non-stop trips between any pair of innumerable small stations, which should make it the mode of choice for city dwellers. Capsi is a fully automated minaturised on-demand 24-hour public transport system that uses narrow 2-seater (or mini-container) carriages running securely between under/over guideway rails.


Millions of city dwellers wrestle daily with the problems of getting themselves to work and back, kids to school and back, doing the shopping and meeting up with friends. Stores and factories need to move materials and goods - much of which can be moved in crates, bags or boxes that are easily manhandled. The situation has existed for centuries, during which time new systems of transportation have evolved, flourished and vanished. It is difficult for a youngster today, looking at a picture of a central city area crowded with animal drawn wagons and carriages, to imagine what life was like a century ago. A century from now, will youngsters be puzzled by images of the huge carparks, multi-lane highways and giant tube trains that dominate the city today?

The motorcar/road system has served us well, but the environmental costs and capacity limitations are now sufficiently evident to make city dwellers interested in alternatives.


Private cars. What we like about our private cars, vans and pickups is that they are available to us personally, at all times; they go from where we are to where we wish to be (single-stage journey), they go just about anywhere and we feel pretty safe - even when venturing into strange parts of the city at night or traveling long distance. On top of that, they can be a pleasure to ride in, we can take people and/or goods along with us and the vehicle we choose can greatly enhance our personal status. We only need consider costs of ownership – the rest of the system is provided and maintained by others.

Motorvehicles are highly desirable, and certainly preferable to low-fare three-stage alternatives such as buses or trains, which require us to get to the boarding point, forego privacy, submit to their timetable, and after the ride find our way to where we really want to be.

What we don’t like about motoring are traffic congestion and parking difficulties. When heavy congestion persists we are compelled to consider alternatives. For some the choice might be bus, tram, train or tube - even cycling or walking! Others would rather move house and/or change job.

Cars and cities. Transportation modes have an enormous effect on cities and their surroundings. Compare today's' cities, made for motor vehicles, to ancient cities made for people and agriculture. Motor roads in cities, and the space given to parking lots and multi-lane ring roads, could be as much as one quarter of the total surface. There are now numerous cities whose streets, overcrowded by motor vehicles, cannot be expanded further.

Land consumption is extensive in another respect as well. Whereas canals and railways created linear development, the motor vehicle system easily converts all farmland and wilderness areas into suburbia. Are today’s cities really the way we prefer them to be?

But motoring is inequitable! Most city dwellers do not own or operate a motorvehicle for any of several valid reasons: they cannot afford it, it does not come with the job, they may be too young, too old or otherwise unable/incapable of owning or operating one. Yet they they, too, must endure the objectionable consequences of the motor vehicle system.  Motorists feel victimised when they are restricted or forced to subsidize the public transport systems.

Objectives: Top priority for any new transportation system must go to making cities places where people feel safe, and enjoy living and working. The system must release land for people, trees, flowers and agriculture to be part of daily life once more. It should be widely affordable, reduce the time required to move about each day, minimise levels of noise and air pollution, and ensure personal safety.

Capsi! Capsi!

Before describing the Capsi design concept, come for an imaginary ride in the Capsule taxi, Capsi.

Personal Identification(PI). First, you need to sign on and be in possession of a Capsi smart card (pre-paid or account), PIN and map. For maximum safety - yours, as well as that of all other users - Capsi must be able to positively identify all users.

Walk, or roll your wheelchair, to the nearest Capsi station, which will look like an elevator with glass doors and an ATM. Stations are small and everywhere (see illustration) - in building foyers, on every block of the street, at schools, shopping centers, and in private homes. The Capsi concept is to have as many small stations as possible, in contrast to the concept of large central stations and suburban stations or bus stops a ten-minute walk apart.

Swipe your Capsi card, enter your PIN and your destination station number (see illustration). From the screen menu select capsule quality (austere to super luxury) and speed (gentle, normal, fast - sets maximum g-force), then wait for the DF response.

DF. Capsi operates on a 10-second time module, all trips are non-stop and, unless otherwise requested, route selection is based on least time. Within 10 or 20 seconds Capsi will quote D (trip Duration in seconds from acceptance to destination) and F (Fare, dependant upon vehicle, current demand and distance). Users thus avoid being trapped in a jammed system and may adjust the trip to suit their immediate needs. Revise your request, or accept and prepay by swiping your card again and you will reach your destination within the time quoted.

There are built-in automatic entry/exit controls, but within a few seconds the doors will open to reveal an empty capsule and allow you to enter. The capsule will have two (flip up) seats, for you and your traveling companion or luggage (wheelchair or folding bicycle). The seats congenially face one-another and the capsules may move in either direction For safety, there is a  central air bag. Once you commence moving, however, you will only stop when your destination is reached.

Every passenger capsule will have a set of controls for each passenger. These include a clock indicating your trip seconds remaining, capsule-to-control speakerphone, a door-opening button and emergency buttons for immediate trip abort, for aborting to the nearest security checkpoint, or to send the capsule to the Capsi service depot at the end of your trip should you find left luggage or be aware of any damage to the capsule. Capsi staff will be able to contact the previous user to return left luggage or claim for the damage repair costs. If you leave anything of value in the capsule, Capsi will be able to trace the subsequent user. Capsi will ultimately be able to prevent a troublesome customer from using the service.

At your destination you will be prompted to open the doors. Use one of the emergency buttons if it appears unsafe to exit, otherwise press the door release.

Kids to school: Accompany the kids to the Capsi station, swipe your card, enter your PIN, select the school station and say YES to the Attended Destination Confirmation option. This procedure requires a registered user at the destination to respond, and reveals the attendant's identity for your response. On your acceptance Capsi will produce a DF offer. The Attended Destination Confirmation option can be used by staff assisting kids with their trip home, making sure that there is a responsible person at the 'home' station.

A further Capsi option allows users to ask for more than one capsule to ride in tandem. In this manner a teacher might transport a class of, say, 30 children from their school to an event destination, or a party of six might travel together from restaurant to theatre.

Being safe for children means being safe for older people whose eyesight or other infirmity prevents them from motoring at night, or to get about on their own. And being a 24-hour service, Capsi helps late/early-shift workers as well as intoxicated late-night revelers.

Goods delivery. The Kids-to-school technique (Attended Destination Confirmation) may be used for sending un-accompanied parcels in passenger capsules. By using specially adapted Capsi container capsules Capsi would also be able to do many of the tasks done by pick-ups and vans, with the cost advantages of being driverless and one-way. Regular users would thus send and receive Capsi containers with confidence. Anyone thinking of sending a parcel bomb should be prepared to take the risk that detectives with access to Capsi records would somehow be baffled.

Suppose something goes wrong . . ? Sooner or later, something will go wrong. Users will be concerned about the possibility of a collision (even a minor one), a power failure, flood or fire, and being trapped below ground. Naturally, there would be great care taken to prevent a collision, power failure or fire, and the project would have to proceed on the basis that these engineering problems are no more difficult to solve than those encountered in automobile and aircraft design and operation. Where stations are more than fifty meters apart there would be emergency exits provided.


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Capsules. The objective is to miniaturise the system, and in this regard vehicle width is significant. Statistically, the occupancy of 4-seater private motor vehicles is two persons or less. Capsi uses 2-seater vehicles, no wider than a motorcycle, which may be employed in tandem.

The capsules have a pair of doors on either side. At some stations access will be from one side only, but wherever possible users would enter from one side and exit at the other.

The motive power for the capsules would be electricity, most probably on-board electric motors driving two wheels.

Guideway. A narrow upright vehicle with two seats in-line poses the problem of devising a guideway that will keep the vehicle upright and also allow it to switch safely from one track to another. Greater width provides stability for 4-seater vehicles, while roller-coaster vehicles are secure on their rails, but have difficulty switching tracks at high speed.

Capsi's novel solution is to provide two rails, one below and one overhead; and to give each capsule four wheels, two below and two above. (Provisional patent.)

This under/over arrangement means that capsules are firmly held between the rails, even when stationary on a stretch of steeply banked track in a fault situation. The ability to control the attitude of the capsule in a turn means that turns can be tighter and negotiated at far higher speeds with greater safety and greater passenger comfort.

When changing from one track that adjacent, at high speed, passenger comfort will be improved as the upper and lower rails can be made to tilt the capsule over and then right it, as if it were a motorcycle. Because the capsules are narrow the rails can be close together and the manoevre can be completed within a short distance.

A further advantage of the under/over track concept is that wheel/rail traction can be adjusted by loading to suit various situations. Traction could be increased during acceleration and braking, and to enable the capsules to traverse steep gradients - steepness being limited only by considerations for passenger comfort.

The versatile Capsi guideway concept means that stations may be at any elevation, from below ground to overhead without requiring steps, lifts or escalators. Where the system is below ground, stations can be at street level, occupying no more than three standard car parking bays.

Tubular Corridor. Two tracks (lines or lanes) provide much greater service capacity than one, particularly when used for travel in either direction. Two tracks (four rails) can be accommodated within a tube with an internal diameter of 2,0 meters.

The Capsi concept is to apply this space requirement (2m dia) as a minimum - whether below or above ground. The tubular space may be straight, or curved in any direction. The rails inside the tube would be rotated on the major axis to provide super-elevation as required for the design speed of that portion of track. There is space overhead for wiring and below for drainage.

Below-ground applications would require the tubular wall to be structural, while above ground applications might employ the tube as a structural member to span between supports. Alternatively provide a tubular metal cage (to keep the corridor clear) around a structurally efficient I-beam for excellent space utilisation. While there is considerable free space (minimum 35% of the cross-sectional area free when two capsules are alongside), the pneumatic effects at various speeds would need to be investigated.

The incredibly small tube size (compared to the typical underground railway!) greatly reduces the cost of tunneling, or excavation (tubes inserted from above). The ability of the system to turn at very tight radii, and to negotiate steep inclines and descents means that it is highly adaptable.

Capsi, in effect, puts a 7 meter wide roadway underground! In doing so Capsi improves transportation capacity, reduces conflict between vehicles and anything else, removes fumes and noise and gives the land back to people and plants.

Control system. Progress during the last couple of decades in computer and digital technology, as well as credit card security systems, has shifted this aspect of the 40-year-old dream from being the most daunting to the most feasible.

The CAD drawing concept of transparent overlays might be adapted for planning and recording all trips. Imagine one layer for every ten-second time interval, where present time layer (T) is separated from past time layers (PT) below and future time layers (FT) above. Each capsule would have to be positioned somewhere on layer T. PT layers would record each capsule's previous positions and thus trace and record its movements, while FT layers would plan each capsule’s future movements.

Because the capsules move in either direction, the control system may use each portion of track as it chooses. The number of stations and capsules that could be safely managed by one computer would be limited and constitute a single geographical Capsi cell. Each cell would be capable of accepting capsules from adjacent cells and routing them either to a destination within that cell or to move them through to another cell. Cells will facilitate the incremental introduction of the system and assist with fault management.


Imagine the pleasure of living in a leafy, tranquil 'farmyard' city where there is absolutely no need to own a motor car! Go anywhere, door-to-door, with no congestion or parking problems. Vary your journeys at will, sometimes going briskly and at other times opting to walk or cycle any portion. How else could your grandmother be able to go out at night in a snowstorm on her own? Think of kids having fun going on high-speed (max g-force) trips; or taking the round-trip option from wherever you are to the open air Capsi 'Space Center' with barrel rolls, zero-g loops and corkscrews, and back. There would no longer be the danger of sharing roads with drunk, impatient, absent-minded, stupid, aggressive, lawless, anti-social and un-licensed drivers, with mechanically defective motor vehicles, or any combination of such. No fumes and very little noise.

John Stegmann 2002

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Last modified: March 27, 2003