I suppose it's 追加, i.e. to add, to include as a supplement.
No. 59 - The things you gave meGanbare Kreigmarine! (Fight Hard, German Navy!)Increasing her bulgeGraf ZeppelinCatapault, present8 x 15cm anti-aircraft guns, presentWhat's wrong onee-chan?Leave me alone....Around herebut...
[Construction Halted]Aircraft Carrier "Weser"
(alias "Seydlitz")