أنشئ حسابًا أو سجّل الدخول للانضمام إلى مجتمعك المهني.
<p>In some condos in an emergency there should be a method of transporting people from upper floors to ground floor & 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>
