Elevator and Escalator Consulting Engineers
The Third Dimension
Over the next fifty to one hundred years with the increasing height, size and complexity of large multi-use inner city complexes, in-building transportation systems will be extended from the present elevator cabs each with its own hoistway to an integrated horizontal and vertical people-moving plant. In the following, possible features of such a transportation system are discussed.
The “people container”, formerly known as the “elevator cab” will morph into a smaller box which we will, for convenience call a “pod”. The pod will accommodate six passengers with three rows two seats and with three doors on either side of the pod - not unlike a variation of an automobile but without the hood and trunk. The doors need not be powered; they can be similar to a standard automobile door.
This pod design allows quick loading and unloading as well as presenting to the passengers, because of the likeness to the automobile, a familiar aspect.
Each pod will have its own electric motor and storage batteries similar to present-day electric automobiles and would run on tires, again much like automobiles.
These pods will travel horizontally within the complex and when they are required to move vertically they will enter “elevator” shafts and travel up or down the shafts. This transition between horizontal and vertical movement will involve a ninety degree rotation of the driving mechanism and this is obviously one area where much new design work would be involved.
The vertical shaft in which the pods travel can be enclosed in walls finished with the same material as the building floors and the pod tires can run up these walls. To prevent the pod from falling down the shaft and to give it traction on the walls, additional tires would be extended on the other side of the pod. Thus the pod would be driven by eight tires, one at each corner, with horizontal pressure between the two top pairs of tires and with horizontal pressure between the two bottom pairs of tires. The horizontal pressure would have to be sufficient to keep the pod from falling.
Alternatively, the vertical shaft could contain a track and the pod could drive up and down on this track. The track could be a rack with the pinion on the pod. Tracks on either side of the pod would provide greater stability. This rack and pinion system is presently employed on many construction hoists and presumably, with more advanced materials and technology, could be successfully used in this application.
Some of the current technology would serve us well. The pod could be constructed of carbon fibre or nanotubes thus minimizing the weight of the pod.
So as to maintain the passengers in an upright position, the passenger compartment of the pod could be mounted on a gimbal carriage or it could be rotated as necessary when transferring between the horizontal and vertical forms of travel.
One of the major differences between the future pod and the current elevator cab is the provision of more space and the transfer in a seated rather than standing position. The space available in an elevator cab has to be restricted to avoid using too much of the building for vertical hoistways. Many more passengers can be accommodated within the cab in a standing position as opposed to a seated position. We take it as a given that people stand in an elevator cab but in fact this was a requirement that was forced on elevator system designers from the onset of “high” building design in the late nineteenth century. With the use of pods, we now have much more space for each passenger since we are running multiple pods in the same shaft.
It is apparent that there are similarities between the pod and the unmanned automobiles presently in limited use. The pod would borrow much of the technology developed for the automatic automobile. For example, using similar guidance systems, the pods could follow flexible routes within the building complex; it would not be necessary to assign specific paths or corridors for pod movement. This, of course, is a pleasant happenstance for leasing agents since the floor layouts would not be absolutely dependent on the transportation layout.
These same similarities between the pod and unmanned automobiles lead to the natural conclusion that both systems could be linked. Within the city of the future a pod could be taken from any point in one building to any other point in another building.
What is preventing us from immediately manufacturing pods and building new horizontally-vertically integrated complexes?
Scale is one factor. To develop such a system for a two floor townhouse would not make much economic sense. To move forward with a new design such as this the building complex would have to be sizeable - probably in the ten million square foot range if not larger. Such a complex implies or demands government intervention or assistance in a major way.
A lot of the technology is iffy in our present stage of knowledge. In particular, the means of storing energy on each pod, which we have casually referred to as a “battery”, is crucial. Today's batteries leave much to be desired and, although used in the electric automobile, there is considerable doubt as to their longevity. As well, they are heavy. This is less of an obstacle for an automobile that only has to overcome gravity on modest inclines; it is quite another matter where the full force of gravity is imposed on the pod when travelling vertically. The consequence of greater weight is the need for more power to drive the pod; which means a heavier motor and drive which means greater weight which means a larger battery ... and so on. Probably we will need a major breakthrough in energy storage technology and indeed it is strange that something major in this area has not happened in the last fifty years. What we need is an energy storage device a hundred times smaller and lighter than the present ones although perhaps ten times smaller and lighter would do.
Still, the idea that one day people will call up a pod or reserve a pod (in the same way we do today for a taxi), climb in it and go from a residence directly to any destination in any building anywhere in the city is not far-fetched.