 The ships had an overall length of 152 metres ( 498 ft 8 in ) , a beam of 27 @.@ 90 metres ( 91 ft 6 in ) , and a draught of 8 @.@ 70 metres ( 28 ft 7 in ) at deep load . They displaced 20 @,@ 000 tonnes ( 19 @,@ 684 long tons ) at load and 21 @,@ 689 tonnes ( 21 @,@ 346 long tons ) at deep load . 
