Pipelaying under ice by bottom pull
AssigneeMontreal Engineering Company, Limited
InventorRoger McGovern
Life of this patent
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Abstract
A method of laying an underwater pipeline underneath an ice sheet by a bottom pull which includes making up a pipe string, on a first shore of a water crossing, providing a first cable connection along the upper surface of the ice sheet between a pulling location and an on-ice pull sled, attaching a second cable between the pull sled and the leading end of the pipe string, cutting a slot through the ice along the path which the pipe is to take, ahead of the pull sled, and pulling the pull sled over the upper ice surface so as to tow the pipe string along the water bottom by means of the second cable which is submerged through the slot.
Claims6
A method of laying an underwater pipeline underneath an ice sheet by a bottom pull, comprising:
- locating a pipe string to be laid adjacent a first shore;
- providing first flexible cable means along the upper surface of the ice sheet;
- connecting said first cable means, on the one hand, to pulling means located at a pulling point, and on the other hand, to an ice surface pull sled;
- attaching a flexible underwater cable means between said pull sled and the pipe string to be laid;
- cutting a slot through the ice with an ice ditching means along a projected pipelaying path ahead of said pull sled;
- and operating said pulling means to pull said sled over the upper ice surface along said path and tow said pipe string along the water bottom by said underwater cable means through said slot.
Dependencies are inferred from the claim text.