Patent ID: 8545131

Claim:
A ship lock for a first ship and a second ship to move between a first and a second waterway comprising: a first chamber, having first chamber water therein, located between a first waterway and a second waterway, said first chamber having a first port and a second port leading respectively to said first waterway and to said second waterway for a first ship to pass through; a second chamber, having second chamber water therein, located between said first waterway and said second waterway, and proximate to said first chamber, said second chamber having a third port and a fourth port leading respectively to said first waterway and to said second waterway for a second ship to pass through; a first slave tank open to the atmosphere and proximate to said first chamber and to said second chamber, and located to be in fluid communication with both said first chamber and said second chamber; said first slave tank sized and located at an elevation that permits one sixth of the first chamber water in said first chamber being drained during a lock operating cycle to flow out only by gravity to said first slave tank, and that also permits said first chamber water in said first slave tank to subsequently flow only by gravity from said first slave tank to the second chamber being filled during said lock operating cycle; a second slave tank open to the atmosphere and proximate to said first chamber, and to said second chamber, and to said first slave tank, said second slave tank located to be in fluid communication with both said first chamber and said second chamber; said second slave tank sized and located at an elevation that permits the one sixth of the first chamber water in said first chamber being drained during a lock operating cycle to flow out only by gravity to said second slave tank, and that also permits said first chamber water in said second slave tank to subsequently flow only by gravity from said second slave tank to begin filling said first chamber during the next lock operating cycle; connecting means extending between said first chamber and said second chamber including a plurality of pipes with valves fluidly connecting said first chamber to said second chamber, and said first chamber and said second chamber to said first slave tank, and said first chamber and said second chamber to said second slave tank, and further connecting each said first chamber and said second chamber to said first waterway and to said second waterway, said connecting means operable to direct water from said first chamber into said first slave tank and vice versa, from said first chamber into said second chamber and vice versa, from said first slave tank into said second chamber and vice versa, and from said first chamber into said second slave tank and vice versa, said connecting means also operable to direct water from said second slave tank into said second chamber and vice versa.