It is also possible to upgrade these submarines with the latest Air-independent propulsion (AIP) systems. The first ships to receive this upgrade were to be three ships of the Greek Poseidon class Type 209/1200 under the Neptune II upgrade program. They were to be upgraded by cutting the boat in half aft of the control room and adding a 6 m plug with a 120 kW Siemens AIP system to the ship. The program was canceled in 2009 due to cancellation of the Archimedes Project (Type 214), but not before Okeanos (S118) completed the upgrade. After the Archimedes Project settlement was reached, it was decided that instead of upgrading the remaining two Type 209s, two additional Type 214 ships were to be ordered, but that deal was cancelled by Howaldtswerke-Deutsche Werft. Turkish Navy's AIP upgrade of Atılay-class (209 Type 1200) was also shelved in favor of acquiring new Type 214 subs.