In Costa Rica (wet tropics) we wish to build a tramway of about 700 meters length which is almost perpendicular. This would be powered by water weight. There would be two cars, one a 4 person passenger car and the other containing an easily loaded or emptied water tank,the heavier car moving downwards. This is to climb a slightly sloping, forested cliff. There is a good sized stream on top which becomes a spectacular waterfall.

If the water car is at the top and the passenger car below, the passengers enter and water is allowed to fill the tank in the other car. The water car moves downwards raising the other car. This movement is controlled by brakes. When the passengers leave the car which has reached the top, passengers to go down enter and the water tank is emptied, reversing the weight arrangement.

Does this make sense to anyone with experience in tramways?