Struc­tu­ral Per­for­mance of An­chor To­wing Win­ches

The ex­ploi­ta­ti­on of oil fiel­ds in in­crea­singly hars­her en­vi­ron­ments re­qui­res ever stron­ger Off­shore Sup­ply Ves­sels for the an­cho­ra­ge of the dril­ling plat­forms. The same ap­plies for the win­ches on­board the as­sis­tan­ce ves­sels.

Some in­ci­dents in the re­cent past de­mons­tra­ted that the per­for­mance of win­ches and founda­ti­on struc­tu­res did not fit the strength re­qui­re­ments. Da­ma­ges oc­cur­red from load in­du­ced mi­s­a­li­gn­ment of the gear wheels. The wheels ob­vious­ly de­flect in trans­la­to­ry and ro­ta­to­ry mo­vements and thus their teeth grip pat­tern be­co­mes in­suf­fici­ent. As a re­sult heavy wear in short pe­ri­ods oc­cur­red fre­quent­ly.

The pro­ject in­ves­ti­ga­ted the teeth grip pat­tern of ty­pi­cal win­ches as a func­tion of the struc­tu­ral stiff­ness and in com­bi­na­ti­on with the sup­por­ting deck struc­tu­res.