Complaint riser yoke assembly with breakway support means

In a compliant riser for connecting a marine hydrocarbon production system between a marine bottom base through a fixed-position riser section and flexible flowline section to a surface facility, the improvement which comprises:

• slotted, lateral support arms mounted on the fixed riser section at a top portion thereof for receiving a yoke beam beside the fixed riser section;
• yoke assembly means including said yoke beam for supporting one end of a plurality of flexible conduits in catenary arrangement and retaining said conduit ends in spaced apart positions between said lateral support arms;
• releasable beam end support means at each end of said yoke beam for mounting said yoke beam adjacent the fixed riser section on a corresponding one of said lateral support arms;
• each of said releasable beam end support means comprising at least one laterally-projecting beam extension member extending outwardly from the beam end over a corresponding one of said lateral support arms and adapted for passing through a mating slot in said lateral support arm, and horizontally-retractable pin means disposed between each of said beam extension members and its corresponding lateral support arm, each of said pin means including a span portion overlying the corresponding support arm slot and directly supporting the corresponding beam extension member, whereby said yoke beam bears indirectly on said lateral support arms through each of said pin means;
• power means for retracting each of said pin means and corresponding span portion away from the corresponding support arm slot;
• and
• said yoke assembly means and said lateral support arms being disposed to permit said yoke assembly means to fall freely from the fixed riser section and said support arms by retracting at least one of said pin means.