A system for the storage and traction of a cable, in particular a synthetic cable fitted to an offshore crane, wherein said storage / traction system comprises a frame that carries a combination of devices (6, 7, 8) cooperating with said cable: (i) a storage device including: - a storage reel on which said cable is intended to be wound, - a support, carrying said storage reel through assembly means defining an axis of rotation, and - a motorization, adapted to rotate said storage reel about said axis of rotation, (ii) a traction device, adapted to exert a traction on said cable, wherein said traction device includes at least one drum associated with a motorization, and (iii) a winding device, interposed between said storage device and said traction device, to guide the cable during the winding / unwinding thereof with respect to said storage reel, wherein, between said storage reel and said support, said assembly means consist of a single slewing ring comprising two rings that are free to rotate with respect to each other: - a fixed ring that is fastened to said support, and - a moving ring that is, on the one hand, fastened to said storage reel and, on the other hand, rotated by said motorization. wherein said storage / traction system comprises a frame that carries a combination of devices (6, 7, 8) cooperating with said cable: (i) a storage device including: - a storage reel on which said cable is intended to be wound, - a support, carrying said storage reel through assembly means defining an axis of rotation, and - a motorization, adapted to rotate said storage reel about said axis of rotation, (ii) a traction device, adapted to exert a traction on said cable, wherein said traction device includes at least one drum associated with a motorization, and (iii) a winding device, interposed between said storage device and said traction device, to guide the cable during the winding / unwinding thereof with respect to said storage reel, (i) a storage device including: - a storage reel on which said cable is intended to be wound, - a support, carrying said storage reel through assembly means defining an axis of rotation, and - a motorization, adapted to rotate said storage reel about said axis of rotation, - a storage reel on which said cable is intended to be wound, - a support, carrying said storage reel through assembly means defining an axis of rotation, and - a motorization, adapted to rotate said storage reel about said axis of rotation, (ii) a traction device, adapted to exert a traction on said cable, wherein said traction device includes at least one drum associated with a motorization, and (iii) a winding device, interposed between said storage device and said traction device, to guide the cable during the winding / unwinding thereof with respect to said storage reel, wherein, between said storage reel and said support, said assembly means consist of a single slewing ring comprising two rings that are free to rotate with respect to each other: - a fixed ring that is fastened to said support, and - a moving ring that is, on the one hand, fastened to said storage reel and, on the other hand, rotated by said motorization. - a fixed ring that is fastened to said support, and - a moving ring that is, on the one hand, fastened to said storage reel and, on the other hand, rotated by said motorization.