had to be capable of inter-service operations with the Troupes de Marine brigades of the French Army. Evolution of the concept The studies for a multi-purpose intervention ship (, BIP) began during a time where the defence industries were preparing to undergo restructuring and integration. The BIP was intended to be a modular, scalable design that could be made available to the various European Union nations and constructed cooperatively, but political issues relating to employment and repartition of contracts caused the integration of the European nations with naval engineering expertise to fail, and saw the BIP project revert to a solely French concern. In 1997, several common ship designs referred to as (NTCD), loosely based on the aborted PH 75 nuclear helicopter carrier, were revealed. The largest design, BIP-19, was the future basis of the Mistral class. The BIP-19 included a long flush deck, with a beam, a draught of , and a displacement of 19,000 tonnes; dimensions which exceeded the requirements of the NTCD concept. Three smaller ship designs were also revealed, basically scaled-down BIP-19 versions, with a common beam of : BIP-13 (13,000 tonnes, ), BIP-10 (10,000 tonnes, ), and BIP-8 (8,000 tonnes, ). BIP-8 incorporated features of the Italian amphibious transports, but with a helicopter hangar. At the design stage, the NTCD concept featured an aircraft lift on the port side (like the U.S. ), another on the starboard side, one in the centre of the flight deck, and one forward of the island superstructure. These were later reduced in number and relocated: a main lift towards the aft of the ship was originally located to starboard but then moved to centre, and an auxiliary lift behind the island superstructure. Concept drawings and descriptions created by Direction des Constructions Navales (DCN), one of the two shipbuilders involved, showed several aircraft carrier-like features, including a ski-jump ramp for STOBAR aircraft (like the AV-8B Harrier II and F-35B fighters), four or five helicopter landing spots (including one strengthened to accommodate V-22 Osprey or CH-53E Super Stallion helicopters), and a well deck capable of accommodating a , or two LCAC hovercraft. A French Senate review concluded that STOBAR aircraft were outside the CNOA's scope, requiring design changes. The NTCD was renamed Porte-hélicoptères d'intervention (PHI, for "intervention helicopter carrier") in December 2001, before being eventually named Bâtiment de projection et de commandement (BPC) to emphasize the amphibious and command aspects of