Charles de Gaulle - Modifications
The cost of the Charles de Gaulle program was estimated at 20 billion francs in 1999. The construction of the aircraft carrier accounts for two thirds of this sum, the other third corresponding to the fixed costs of development and logistics. Compared with the estimate established in 1985, the overrun is 18%. One third of this additional cost is attributable to budgetary shifts and another third to changes in nuclear safety standards. A final third is related to the prototype character of the building. Most of this extra cost (16% of the 18%) came before 1995, the additional cost resulting from modifications deemed necessary after the trial periods at sea and on shore. The construction of the aircraft carrier accounts for two thirds of this sum, the other third corresponding to the fixed costs of development and logistics. Compared with the estimate established in 1985, the overrun is 18%. One third of this additional cost is attributable to budgetary shifts and another third to changes in nuclear safety standards. A final third is related to the prototype character of the building. Most of this extra cost (16% of the 18%) came before 1995, the additional cost resulting from modifications deemed necessary after the trial periods at sea and on shore.
During the test period from January to September 1999, the vessel had nearly 96 days of navigation and 256 berths by the modernized Super Etendard (SEM), Rafale and Hawkeye. These tests, and those that will follow, allow to test each equipment and to adjust, as and when, the residual difficulties. As Charles de Gaulle integrated a large number of installations with a prototype character, the qualification of each was carried out in an industrial process which ended with final tests, in real environment, to highlight the Final adjustments needed.
In the first round of tests, scheduled for 25 January 1999, had to be delayed for weather reasons, as the propulsion system and the maneuverability of the ship had not been tested in full scale. On its first outing, scheduled for eight days, the aircraft carrier suffered several damages which required the return of the vessel to Brest within 48 hours. The failure of an electric pump in the secondary cooling system prevented the operation of the boiler rooms beyond 50% of their maximum power, which was necessary for the scheduled tests.
These pumps supply water to the two generators dedicated to the propulsion of the aircraft carrier. This supply of water is made by special pumps whose motor contains special ball bearings for its operation. At their level, a over-heating occurred. In order not to risk deteriorating them, the decision was taken to stop them, to return to port and to resume a series of studies and tests on shore.
After a series of sea trials, the post-test retrofit period (RANAE) ran from October 1999 to May 2000. During this phase, significant work was carried out, at a cost of 400 million francs. To the ordinary adjustments were added maintenance operations related to the very long period of construction of the vessel. The main work carried out concerned the bringing into conformity of the boiler rooms with the new European standards of radiation protection, the reliability of the electrical plant, extension of the premises of the General Staff, and the extension of the oblique runway. Similarly, it was necessary to carry out the recovery of the deck of the take-off bridge, an intervention on the steering gear, and finally the installation of a fifth coupe.
The radiation protection work was to adapt the protections to the new international regulations on the subject, which fixed the limits of exposure of the public and workers to artificial radiation caused by nuclear installations. It is enacted by the International Commission on the Prevention of Ionizing Radiation (CIPRI). The old standard, ICRP 26, had already imposed work in 1998, and the new was much more restrictive. It imposed a ceiling of artificial radiation in some cases lower than natural radiation. The adaptation of the aircraft carrier's facilities consisted of adding an absorbent shield inside the boiler rooms. It was precisely this new layer of absorbent, placed too close to the thermal insulation of the tank which, when heated, engaged a slow combustion (28 February 2000). Substantial operations were then necessary, causing a total of 6 weeks delay of the date originally scheduled for completion of the post-test refit.
The flight deck was extended by 4.40 meters to add a runway for the Hawkeye landing. This modification represented a cost of 5 million francs. Under the original program in 1986, the aircraft carrier was designed to allow the catapult, the landing and maneuvers on the deck of the Super Etendard, the Rafale and possibly F/A-18C/D. The choice, in 1992, of the Hawkeye as a lookout aircraft changed the situation. Although the deck was designed to allow catapulting and landing under normal safety conditions, its handling at the end of the flight deck during deck landing in extreme conditions would have risked slowing down its conveyance to the hangar park and preventing others Rapid succession. The aircraft has a very large wingspan for an aircraft carrier, close to 25 meters.
Another intervention was necessary on the flight deck: the change in paint on the runway's surface, which was found to be too abrasive for the new brake cables of the Charles de Gaulle stopping brakes. A new liner was therefore chosen and installed on the deck.
In addition, during the second outing at Charles de Gaulle sea ??from 18 to 30 March 1999, a vibratory phenomenon appeared in the steering gear during the high-speed tests. Despite these difficulties, the Charles de Gaulle could reach a speed of 20 to 22 knots, or even 28 knots in a straight line. Further studies made it possible to locate the source of the dysfunctions: The rear rudders were slightly moved to lie in line with the propellers.
The aircraft carrier was ready in October 2000 for the armament closure, which marked the delivery of the ship by the DGA to the Navy.
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