Method and apparatus for tapping a submerged pipe

A process for preparing confronting ends of a submerged pipe for tapping after two preliminary traverse cuts have been made in said pipe in order to removed a section of said pipe thus forming first and second temporary pipe ends, said preliminary traverse cuts being closer together than intended final traverse cuts, comprising the steps of:

• installing a lifting device so that a part thereof is vertically above a first pipe portion terminating at said first temporary pipe end;
• installing a working platform vertically above said first temporary pipe end;
• attaching a modular tool-carrier to a support girder;
• lowering said support girder onto said working platform;
• conducting an operation on said first pipe portion, said operation being one of a plurality of operations consisting of stripping concrete from said first pipe portion, stripping an anti-corrosion covering from said first pipe portion, making a final cut in said first pipe portion, fettling said final cut in said first pipe portion, internally brushing said first pipe portion over a predetermined length thereof, and making a longitudinal weld of said first pipe portion flush;
• raising said support girder to a water surface;
• and
• performing the above steps on said second pipe portion terminating at said second temporary pipe end.

An apparatus for preparing confronting ends of a submerged pipe for tapping after two preliminary traverse cuts have been made in said pipe in order to remove a section of said pipe thus forming first and second temporary pipe ends, said temporary pipe ends being closer together than intended final traverse cuts to be made in said pipe, comprising:

• means for engaging and lifting a first portion of said pipe terminating at said first temporary pipe end, said engaging and lifting means including means for displacing said first pipe portion in vertical and horizontal directions while in contact with a floor;
• a support girder;
• a working platform including means for engaging a pipe while in contact with said floor, said support girder being selectively received on said working platform and being selectively locked thereto;
• said support girder being provided with means for receiving any one of a plurality of tool-carriers, each of said tool-carriers carrying tools required to carry out an operation, said operation being one of a plurality of operations consisting of stripping concrete from said first pipe portion, stripping and anti-corrosion covering from said first pipe portion, making a final cut in said first pipe portion, fettling said final cut in said first pipe portion, internally brushing said first pipe portion over a predetermined length, and making a longitudinal weld of said first pipe portion flush, said tool-carriers including means for being removably attached to said support girder;
• and
• handling and control means adapted to be displaced between a water surface and said floor for handling and controlling said engaging and lifting means, said support girder, and said working platform.