Page 56 - Wire Rope News & Sling Technology
P. 56



                             By William Fischer

         I’d like to start out by wishing all our readers a great
         2018. I hope your holidays all went well. We made
         it through another year, and 2018 looms. The recent
         cold snap that enveloped the country seems to have
         ended, and  hopefully as  the  weather warms,  so
         will our industries prospects. With the possibility of
         infrastructure renewal, maybe we will see a significant
         increase in investment and construction activity.

         Method and apparatus for deep water deployment
         Pat. 8,235,228  U.S. class 212/256  Int. class B66C 23/10
         Inventor: Newt Vaastrand, Blommenholm, NO.
         Assignee: Aker Marine Contractors AS, Oslo, NO.
           A method of deploying an object onto the seabed in very
         deep water from a vessel having a heave compensated deck
         crane, comprises lowering the object a distance into the sea
         while being suspended in the crane wire. In an initial step,
         a first fibre rope section of a first length is connected to the
         object via a first connector on the object before the lowering
         is started and is freely run out supporting from a storage reel

                                                              Figure 2: Transverse section of the vessel, showing the start of the first
                                                              sequence of the deployment operation.
                                                              during the descent. Subsequently, the first rope section is the
                                                              object via a second connector located at the upper end of the
                                                              first rope section, the second connector being supported by a
                                                              support mechanism on the vessel deck, followed by off-loading
                                                              the crane wire and disconnecting it from the object and heav-
                                                              ing it up said first length for connection to the second connec-
                                                              tor at the vessel deck and taking over the load of the object.
                                                               Next, the object is lowered a second length into the water
                                                              by the crane while a second rope section connected to the
                                                              second connector is freely run out from a storage reel until a
                                                              third connector located at the upper end of the second rope
                                                              supports the load of the object in the support mechanism,
                                                              whereupon the crane hook can be released and be brought
                                                              up for  re-connection  to the third connector  for  the subse-
                                                              quent deployment, and any further deployment by addition
                                                              to the string of ropes, thereby allowing the object to reach a
                                                              depth of up to 3000 meter, or even more.
                                                               Figure 1 is showing the support mechanism  1 made  up
                                                              by a hang-off cradle 2 supporting the roundel plate 3 that
         Figure 1: Front and side elevations and a section through the support   is connecting the 1000 meter rope sections 4. The roundel
         mechanism comprising a hang-off cradle capable to support roundel   3 has a number of holes in the circumference for rope and
         plates that are connecting 1000 meter rope section.  crane hook connections via rope thimbles 5 and shackles 7.
         56     Wire Rope News & Sling Technology   February 2018
   51   52   53   54   55   56   57   58   59   60   61