 Swordfish could carry 102 long tons ( 104 t ) of fuel oil , which her builders estimated gave her an endurance of 3 @,@ 000 nautical miles ( 5 @,@ 600 km ; 3 @,@ 500 mi ) at a speed of 8 @.@ 5 knots ( 15 @.@ 7 km / h ; 9 @.@ 8 mph ) on the surface . On her batteries her submerged endurance was 60 nautical miles ( 110 km ; 69 mi ) at a speed of 6 knots ( 11 km / h ; 6 @.@ 9 mph ) . 
