In the construction industry, the volume of a building is an important parameter for its construction costs. Though the shape which could have the greatest usable internal storage area for its external surface area would be the sphere, this concept is impracticable for buildings, namely parking structures. The next most efficient shape is the cylinder, and this deemed to be an effective compromise between the sphere and the current more expensive conventional cube formats already in use at the moment.

Sphere Smallest Possible Volume	Cylinder Smallest Usable Volume	Cube Largest Volume

A transportation vehicle, the TENDER, is used to move the vehicles up or down this cylindrically shaped building. This TENDER belongs to the group of driver-less vehicles which are widely used today in production plants and other industrial situations, performing routine tasks in internal company storage and conveying techniques.

The TENDER is a moving vehicle, or "truck", which is equipped with

all-wheel drive
electric motors with brakes and gear
solid tires (industrial standard parts for heavy loads)
a shuttle device for lifting and moving a car forward or backward
automatically

and is

driven by its tires along a single track
steered by mechanical means
operated and controlled solely by computer

Transportation of this TENDER from the bottom of the cylindrically shaped building to the top is achieved by means of a single track formed like a spiral (or auger). The tires of the TENDER run on this track, and when the TENDER revolves, this causes its tires to run up or down the track which gently slopes.

The TENDER twists one way, the tires run up the track, and the TENDER moves upward.

The TENDER twists the opposite way, and the tires run down the track , and the TENDER moves down towards the exit chamber.

Conventional heavy duty elevators, which are slow, have a tendency to creeping (misalignment) and are prone to failure, are eliminated. The TENDER rolls on tires up or down on its sloping track. The weight is therefore supported by the wheels and the alignment with the storage chamber does not have to be performed against the full load as is it is the case with elevator type of storage systems.
Access to each single car storage chamber is possible at any time that the computer commands, as GRANDO® allows full random access to each chamber in the system.

This system utilizes two optimum physical concepts:

Cylindrical shape
Gradual ascending or descending movement of units

In reality, we have all the advantages of conventional multi-level "rack storage", but with the added advantage of easier and faster access than mechanical parking stations using the usual elevator system.