220 in position and on through ball pipe 218 cargo base 92 on the yoke 40 is connected to the top of ball pipe 218 to receive the cargo after the clamping arms 84 have securely grasped ball 216 the vessel 10 can rotate freely about the riser the sleeve bearings 202 and 204 permit the ball pipe 218 and the transfer pipe 210 to rotate relative to the riser 12 fig7 depicts a second alternative embodiment generally indicated by reference number 300 of the yoke mooring system for detachably coupling a storage vessel to a riser the riser 12 terminates at its upper end in a cone shaped cap 302 a pipe 304 communicates with the upper end of the conduit 28 and terminates a flange 306 a fluid swivel 308 allows the pipe 304 to rotate relative to riser pipe 28 bearings 310 are positioned between the cone and the ball segment 312 so that the ball segment can rotate about the riser cone 302 a plurality of clamp wheels 314 are arranged about the periphery of the depressions 90 in the clamp arms 84 their axles 316 are tangential to the hemispherical depression in the clamp arm when the clamping arms 84 are closed around the cone 302 on the riser top 300 the clamp wheels 314 bear against the underside of the ball segment 312 thus the ball segment 312 can pivot in a vertical plane by rolling on the wheels 314 a pipe arm 320 on the yoke 40 has a flange 322 at its end which abuts against flange 306 a quick coupler 324 joins the flanges together and maintains arm 320 locked to the riser when the coupler.