▁number ▁ 5 8 9 , ▁launched ▁on ▁ 2 9 ▁January ▁ 1 9 4 2 ▁and ▁commission ed ▁on ▁ 1 2 ▁March ▁ 1 9 4 2 ▁under ▁Kap it än le ut nant ▁Hel mut ▁Kö ppe . ▁ ▁Design ▁German ▁Type ▁VII C ▁sub mar ines ▁were ▁preced ed ▁by ▁the ▁shorter ▁Type ▁VII B ▁sub mar ines . ▁U - 6 1 3 ▁had ▁a ▁disp lacement ▁of ▁ ▁when ▁at ▁the ▁surface ▁and ▁ ▁while ▁sub mer ged . ▁She ▁had ▁a ▁total ▁length ▁of ▁, ▁a ▁pressure ▁h ull ▁length ▁of ▁, ▁a ▁beam ▁of ▁, ▁a ▁height ▁of ▁, ▁and ▁a ▁dra ug ht ▁of ▁. ▁The ▁sub marine ▁was ▁power ed ▁by ▁two ▁Germania wer ft ▁F 4 6 ▁four - stroke , ▁six - cy l inder ▁super charg ed ▁dies el ▁engines ▁producing ▁a ▁total ▁of ▁ ▁for ▁use ▁while ▁sur fac ed , ▁two ▁Brown , ▁B over i ▁& ▁C ie ▁G G ▁U B ▁ 7 2 0 / 8 ▁double - act ing ▁electric ▁mot ors ▁producing ▁a ▁total ▁of ▁ ▁for ▁use ▁while ▁sub mer ged . ▁She ▁had ▁two ▁sh aft s ▁and ▁two ▁ ▁prop ellers . ▁The ▁boat ▁was ▁capable ▁of ▁operating ▁at ▁depth s ▁of ▁up ▁to ▁. ▁ ▁The ▁sub marine ▁had ▁a ▁maximum ▁surface ▁speed ▁of ▁ ▁and ▁a ▁maximum ▁sub mer ged ▁speed ▁of ▁. ▁When ▁sub mer ged , ▁the ▁boat ▁could ▁operate ▁for ▁ ▁at ▁; ▁when