▁and ▁B AE ▁Systems ▁comm enced , ▁with ▁the ▁main ▁issue ▁being ▁the ▁estimated ▁ 3 0 0 ▁t onnes ▁increase ▁in ▁weight ▁which ▁could ▁cause ▁potential ▁ha z ard ▁when ▁OP V s ▁are ▁in ▁ice ▁in ▁Ant arct ica ▁as ▁the ▁weight ▁increased ▁over ▁the ▁life ▁of ▁the ▁vessels . ▁ ▁On ▁the ▁ 1 8 ▁February ▁ 2 0 1 0 ▁O tag o ▁was ▁accepted ▁into ▁the ▁Royal ▁New ▁Zealand ▁Navy . ▁N Z ▁Ministry ▁of ▁Def ence ▁claimed ▁the ▁over weight ▁issue ▁was ▁not ▁as ▁bad ▁as ▁previously ▁thought , ▁but ▁" weight ▁will ▁have ▁to ▁be ▁carefully ▁monitor ed ▁during ▁the ▁ship ' s ▁life ". ▁The ▁vessel ▁was ▁scheduled ▁to ▁arrive ▁at ▁Dev on port ▁( A uck land ) ▁Naval ▁Base ▁on ▁ 2 6 ▁March ▁ 2 0 1 0 . ▁Well ington ▁was ▁accepted ▁on ▁ 6 ▁May ▁ 2 0 1 0 ▁and ▁arrived ▁at ▁Dev on port ▁later ▁that ▁month . ▁H M N Z S ▁O tag o ▁arrived ▁at ▁Dev on port ▁Naval ▁Base ▁after ▁further ▁delay ▁in ▁Australia ▁due ▁to ▁engine ▁problems , ▁which ▁were ▁fixed ▁under ▁war rant y . ▁ ▁Design ▁origin ▁Con ce ived ▁as ▁part ▁of ▁Project ▁Prote ctor , ▁the ▁Ministry ▁of ▁Def ence ▁project ▁consisted ▁of ▁acqu iring ▁one ▁multi - role ▁vessel , ▁two ▁off sh ore ▁and ▁four ▁in sh ore ▁pat rol ▁vessels . ▁The ▁Project ▁Prote ctor ▁vessels ▁will ▁be ▁operated ▁by ▁the ▁R N Z N ▁to