Patent ID: 7163177

Claim:
An airship ballast system which comprises: a propeller having a plurality of blades with each blade having a tip: a motor mounted on the airship for rotating the propeller around an axis, wherein the motor generates exhaust gases and the propeller defines a tip path at a distance “r” from the axis; a cooling tube mounted on the airship and positioned substantially coplanar with the propeller tip path at a distance “d” from the axis, wherein the distance “d” is greater that the distance “r”, and further wherein the cooling tube has a first end and a second end, with the first end of the cooling tube connected in fluid communication with the motor to receive the exhaust gases from the motor for transit through the cooling tube to cool the exhaust gases and condense water therefrom in the cooling tube; and a ballast tank mounted on the airship, the ballast tank being connected in fluid communication with the second end of the cooling tube for receiving condensed water therefrom to maintain a ballast for the airship.