How can we operate a manually(hand,pedal) economically a lift with a wheel chair & 3 persons to serve 3 floors when no electric power is available?

<p>In some condos in an emergency there should be a method of transporting people from upper floors to ground floor &amp; vice versa when electricity is not available. Is there any lift which can be operated like a chainblock or by a pulley system or  handwheel or by pedalling by people inside the lift. If an aircraft can be powered by a single person why not a lift with3 persons or2 with a wheel chair</p>