WELDING CHAMBER

摘要

A method of positioning a pipeline across a water-course. A first coffer dam is formed to isolate a first area of the water-course and a first part of the pipeline is then positioned in the first area. A chamber is put at the distal end of the first part of the pipeline. The chamber has an upper portion with an open top and a lower portion as opposed ports to receive the pipeline. The first coffer dam is then dismantled. A second coffer dam is formed to isolate a second area of the water-course. The second area includes the chamber. The first and second areas of the water-course are positioned to include the path of the pipeline across the water-course. A second part of the pipeline is located in the chamber and a aligned with the first part of the pipeline. The ports are sealed around the pipeline. Water is removed from the chamber to allow make-up of the pipeline by joining of the first and second parts within the chamber. The upper portion of the chamber is removed and the second coffer dam is dismantled. The pipeline is then in position. The invention also extends to the chamber useful in the above method.