II BRIEF DESCRIPTION OF A PROPOSED SYSTEM
What is envisioned, is a system of, more or less, autonomously operating, intelligent car-ferries transporting individual, private vehicles over a network of rails, or guideways. Starting at a convenient entrance station, the vehicle is driven on and automatically secured to an awaiting ferry. The ferry then proceeds nonstop at something like 80 MPH to a user designated exit station. While journeying on the system, the driver has literally nothing to do; he is free to pursue a whole range of other activities. Upon leaving the system at the exit station, vehicles proceed normally to a final destination.
A. Unit Carriers
Car-ferries, or unit carriers, or simply carriers are the basic building blocks of the system. The entire system is designed to facilitate their uninterrupted movement. These resemble nothing so much as small flat cars. These are not "flat cars" in the traditional railway sense, rather each is only somewhat larger than a full size sedan, or van - one carrier, one vehicle. There is no inherent reason that commercial vehicles can not also be included, or for that matter driver-less freight carriers; but for the present we confine our discussion to ordinary passenger vehicles.
Once launched on to the system, the carrier will propel itself along the system, transfer to alternate lines where required, and detach itself from the system at the appropriate exit station.
Accordingly, each of these will:
a. Have the means to propel itself along the guideway and know where it is within the system. It will know how to get from any entrance station to any exit station on the system, including alternate routes; and have the means to effect transfer and exit switching.
b. Posses a means to communicate with nearby vehicles, as well as the transported vehicle. The vehicle will also be able to communicate directly with each of the several sector monitors tracking all activity along the system.
c. Have appropriate sensors to know its position relative to others, including relative velocities. The carrier will also possess a longer-range sensor to sweep ahead and insure that no obstacles or obstructions are present on the guideway.
Unlike conventional rail systems in which the intelligence to go as directed is provided by the rail itself (i.e., by switching the track), the main lines of this system are entirely static. The means to effect a switching action are wholly contained within the carrier, and involve no physical movement of the track. This autonomous switching, under control of the carrier, is the key to high density operation. It would be physically impossible to move the track in anything near the time required.
B. Autonomous Switching
One method of accomplishing this is to separate the functions of guidance and support. That is, to provide one guideway for support of the carrier, and another, separate, track for guidance. Unlike present railroad practice, the support wheels would have no flanges, thus facilitating easy movement from one support track to another. A guidance arm would grasp the guidance rail, providing steering to the support wheels. One advantage of “grasping” (as opposed to simply “guiding”) is to be able to apply a downward force to the carrier, thus providing increased traction when required. It also would make it much less likely that the carrier would become derailed in the event of an accident.
The carrier would thus proceed along the guideway guided by the guide-rail until it was required to switch to another line or to exit the system. As it approached a switching point, an auxiliary guide-rail, functionally separate from, but parallel to, the main rail is to be found. To effect a switching action, the carrier engages the new rail, releases the main rail, and is guided to its destination. The design provides that the carrier can not simultaneously fully grasp both rails. Moreover, so as not to require this action to be done hastily, the two rails run parallel (with each providing the identical guidance) for an appropriate distance prior to the switch point.
Obviously, each switching point along the entire system has a similar set of alternate guide-rails, it is entirely up to the carrier to know where to utilize them.
It should not be inferred that static (with respect to the main line) switching is new or unique to this discussion. Several patents,, speak to this subject. We have described, perhaps, only its simplest embodiment. Moreover, it is quite likely that multi-directional switching will be required with multi-line operation. The lesson here is that some means of static switching is essential for high density operation.
C. Packet Operation
To achieve the primary objective, that is to provide maximum capacity, it will be necessary to group individual carriers to form packets of, perhaps 20 to 25, contiguous carriers. Each packet will be separated by headway of some 100 to 200 feet.
The carriers comprising the packet will travel along together at a constant system speed until it becomes necessary for a particular carrier to exit the packet. At this juncture, the exiting carrier informs the packet of its intention to leave, effects an “exit distance” with respect to the contiguous carriers, engages the transfer rail and departs. After the departing carrier(s) is (are) safely off the main line, the remaining carriers move forward and re-establish the packet.
With respect to the exit distance, as all are travelling at the same speed, this need only be a few inches. Moreover, it is primarily a system convenience; provided to insure seamless operation. In the unlikely event that this exit distance is not forthcoming, compliant couplers on each carrier can accommodate an exit notwithstanding.
To launch on the system, a carrier will simply wait till a packet is about to pass, accelerate to system speed, switch to the main track, and append itself to the end of the packet. Alternatively, depending on traffic, a single-carrier packet may also be considered.
For both safety and operational reasons it is essential to completely separate carrier traffic from automotive or other traffic. Accordingly, to this end appropriate barriers, over/under-passes, and protection from debris must be included as a basic, and fundamental, tenet of the system concept. Toward this objective it may in some instances be required to elevate the guideway. We anticipate that this will be the exception; in most instances the freeway itself, augmented by barriers and other devices, should be sufficient.
One might think of the various and many packets moving at a constant velocity along the guideway in terms of a giant conveyer belt. Assuming there is room, a vehicle is plopped on the belt, proceeds to its destination at system speed, is "un-plopped" and moves on. If transfer to another belt is required (i.e., transfer to another line), the vehicle is simply “un-plopped” and “re-plopped” on the new belt If the demand is sparse, the vehicles are plopped more or less randomly. As demand increases, vehicles are formed into close-packed groups, or packets.
Please do not be mislead by our somewhat flip use of analogy. We are serious and we do not suggest that any of this is trivial; it clearly is not. Considerable detailed study is required before one could have total confidence that this approach truly has merit. We will discuss specific aspects of the problem in somewhat more detail later. Nevertheless, with even this barest of outlines, one can begin to appreciate the many advantages.