Offshore deck installation

摘要

A method and apparatus that eliminates the need for a derrick barge to lift the deck into place on a floating offshore structure. A connector is used to connect the transport barge to the floating offshore structure. The connector is a type that allows only relative pitch motions between the transport barge and floating offshore structure in response to sea states acting on the barge and floating offshore structure. The connector is also a type that allows disconnection while large forces are acting on the connector. One or more skidding girders attached to the legs of the deck support the legs of the deck above the skidding surface of the transport barge. A skidding surface on the girders, and complementary skidding surface on the surface of the transport barge and floating offshore structure, allow the deck to be skidded from the barge to the floating offshore structure. Once the deck is in the proper position on the floating offshore structure, the deck legs are lowered into contact with the floating offshore structure by removing spacers provided in the girders. The girders are then detached from the legs of the deck and removed. The deck may also be transferred from the transport barge to the floating offshore structure in a manner where relative pitch between the transport barge and floating offshore structure is not allowed. This is accomplished by also using a knee brace that is attached between a submerged portion of the floating offshore structure and the transport barge.