DU Elevator

This idea builds upon some existing half-baked ideas, but with two important twists:

1. It uses DU, which is a very dense material.

2. It adds the concept of peak time/off-peak time.

First, by using counterweights, the amount of electrical energy uses to raise and lower elevators should be reduced. I'm going to basically have to hand-wave through this point, the design will be more complex than current elevators, but basically, when people go up, counterweights go down, when people go down, counterweights go up, and, if possible, design the elevators so that people can counterweigh each other, that is, a carload of people going down helps lift the carload going up.

The counterweights will be dynamic, i.e., if only one person is on the elevator, less counterweight is used, or the counterweight is geared to a kind of pulley system so that it doesn't drop as far as the elevator is raised.

The counterweights in question will have to be quite heavy, after all, if there are, say 100 people that go to the top floor, and each weighs 200 lbs, we are talking about 10 tons of counterweights. And this pattern would be repeated for every floor.

One of the heaviest substances known to man is depleted uranium. Sure, it's radioactive, but a nice coating of lead (which is also heavy) will dampen the radiation quite nicely. Perhaps additional layers will be called for, i.e, ceramics, plastics, etc, but the radiation can be safely blocked. The new market for DU will reduce the temptation (and availability) to turn DU into armor piercing bullets, etc, where the radioactivity will actually matter. Bullets will chip, burnoff, etc, much moreso than a chunk of DU packed in a nice lead sheath, put to work in elevators.

The final piece of this puzzle is the concept of peak/off-peak hours. Obviously, no machine is perfect, and there will be losses of stored potential energy over the course of the day. But, in some markets, electrical energy is much cheaper during off-peak hours, i.e. 3 a.m. at night when everyone is sleeping.

And this would be when the counterweight system is automatically reset so that all the counterweights are at maximum height, ready for the morning traffic.