 The concrete was delivered in huge steel buckets 7 feet high ( 2 @.@ 1 m ) and almost 7 feet in diameter ; Crowe was awarded two patents for their design . These buckets , which weighed 20 short tons ( 18 t ) when full , were filled at two massive concrete plants on the Nevada side , and were delivered to the site in special <unk> . The buckets were then suspended from aerial <unk> , which were used to deliver the bucket to a specific column . As the required grade of aggregate in the concrete differed depending on placement in the dam ( from pea @-@ sized gravel to 9 @-@ inch or 23 cm stones ) , it was vital that the bucket be <unk> to the proper column . When the bottom of the bucket opened up , <unk> 8 cu yd ( 6 @.@ 1 m3 ) of concrete , a team of men worked it throughout the form . Although there are myths that men were caught in the pour and are <unk> in the dam to this day , each bucket only deepened the concrete in a form by an inch , and Six Companies engineers would not have permitted a flaw caused by the presence of a human body . 
