Patent ID: 7610869

Claim:
A method for loading and unloading compressed natural gas onto and off first and second ships, wherein the ships are capable of sailing on the surface of the sea, the ships have receivers, and the compressed natural gas is storable in tubes that are installed on the receivers; the loading method comprising: establishing a loading zone where natural gas is loadable; placing the tubes in a first holder wherein the first holder is removable from the receivers in order to allow the tubes to be loaded and unloaded onto and off the receivers; positioning the first holder at a first defined level above the surface of the sea; lowering and positioning at least a first receiver of the first ship underneath the first holder and then raising the first receiver of the first ship until the first holder at the first defined level is supported on the first receiver of the first ship; and raising the first receiver of the first ship to lift the first holder above the first defined level; the unloading method comprising: establishing an unloading zone where natural gas is unloadable; supporting a second holder removably on a receiver of a second ship such that the second holder is at a height above a second defined level higher than a level of the surface of the sea; then lowering the receiver of the second ship, while supporting the removable second holder on the receiver of the second ship with the second holder above the second defined level and lowering the receiver of the second ship in such a way as to release the receiver of the second ship from the second holder, which receiver of the second ship had been supporting the second holder; and unloading natural gas from the second holder while supporting the second holder above the surface of the sea in the unloading zone, the loading and unloading method further comprising transferring a third holder along with the second ship from one of the loading and unloading zones to the other of the zones.