 Like all Type VIIA submarines , U @-@ 36 displaced 626 tonnes ( 616 long tons ) while surfaced and 745 t ( 733 long tons ) when submerged . She was 64 @.@ 51 m ( 211 ft 8 in ) in overall length and had a 45 @.@ 50 m ( 149 ft 3 in ) pressure hull . U @-@ 36 's propulsion consisted of two MAN 6 @-@ cylinder 4 @-@ stroke <unk> 40 / 46 diesel engines that totaled 2 @,@ 100 – 2 @,@ 310 PS ( 1 @,@ 540 – 1 @,@ 700 kW ; 2 @,@ 070 – 2 @,@ 280 bhp ) . Her maximum rpm was between 470 and 485 . The submarine was also equipped with two Brown , Boveri & Cie GG UB 720 / 8 electric motors that totaled 750 PS ( 550 kW ; 740 shp ) . Their maximum rpm was 322 . These engines gave U @-@ 36 a total speed of 17 knots ( 31 km / h ; 20 mph ) while surfaced and 8 knots ( 15 km / h ; 9 @.@ 2 mph ) when submerged . This resulted in a range of 6 @,@ 200 nmi ( 11 @,@ 500 km ; 7 @,@ 100 mi ) while traveling at 10 knots ( 19 km / h ; 12 mph ) on the surface and 73 – 94 nmi ( 135 – 174 km ; 84 – 108 mi ) at 4 knots ( 7 @.@ 4 km / h ; 4 @.@ 6 mph ) when submerged . The U @-@ boat 's test depth was 220 m ( 720 ft ) but she could go as deep as 230 – 250 m ( 750 – 820 ft ) without having her hull crushed . 
