On Tue, 20 Jul 1999 08:26:00 -0700 (PDT) Brian D Williams
>The Sears tower solved the elevator problem by having three
>elevators in each shaft, you have to transfer about every 33
>floors, only a few elevators go all the way. Trivia question: How
>many elevators does the Sears tower have? Answer: same as the
>number of floors, 110.
Express elevators could be set up like a conveyor belt, with an 'up' shaft next to a 'down' shaft. That would require sideways car transfer from shaft to shaft at the top and bottom. The shafts would be filled with as many cars as there are express stops.