The method and {HEAD ~ structure} includes defining an inner circumferential seat, and an outer circumferential seat, in {TAIL ~ the vessels bottom}, those seats being disposed inside of and outside of, respectively, the circular wear path previously formed in the bottom 
The method and { HEAD ~ structure } includes defining an inner circumferential seat , and an outer circumferential seat , in { TAIL ~ the vessels bottom } , those seats being disposed inside of and outside of , respectively , the circular wear path previously formed in the bottom
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH