Let us discuss the legendary Redoutable class—the first six French nuclear-powered submarines capable of launching ballistic missiles, forming the naval strategic component of the Force de Frappe.
The photos show the submarine under construction at the Cherbourg naval base, the launch hatches for submarine-launched ballistic missiles (SLBMs), and some of the submarine's interior.
The class was built during Charles de Gaulle's presidency, a time when France had withdrawn from NATO's integrated military command and was seeking to emerge as a power independent of the Russian and American blocs. Constructing the Redoutable class was therefore vital for France; it guaranteed the ability to launch a nuclear retaliatory strike, as it was impossible to destroy the submarines in a preemptive first strike.
The submarine is powered by a light-water nuclear reactor, granting it virtually unlimited endurance for 20 to 25 years; it measures 128 meters in length and weighs 8,000 tons, requiring 14 million man-hours and 6 kilometers of welding to build.
France obtained highly enriched uranium from the United States and developed a test reactor to verify the project's feasibility; all six submarines entered service between 1971 and 1985 and were progressively decommissioned between 1991 and 2008.
Its nuclear armament initially consisted of 16 launch tubes for M1 SLBMs, which were gradually replaced by M2 and finally M4 missiles—systems we will discuss later.
While the United Kingdom was doing the same with crucial American aid, France chose the path of isolation, developing and manufacturing every single component on its own; it embarked on a genuine engineering feat that paid off, resulting in exceptionally high operational readiness—with nearly half of their service time spent submerged—and a system where each vessel had two identical crews (Red and Blue) alternating operations to ensure the submarine remained in continuous active service. France became the fourth country in the world capable of launching nuclear missile strikes from nuclear-powered submarines; during the 1970s and 1980s, the Redoutable class was not particularly quiet in terms of propulsion—making it easier to detect than American and British submarines, though not by Soviet ones until the introduction of the Akula class in the 1980s.
Between the late 1980s and the 1990s, the Redoutable class underwent gradual upgrades—starting with the Inflexible, which entered service in 1985—to improve stealth and modernize the missile systems, effectively creating a transitional subclass of vessels. To minimize sonar detectability, the Redoutable class employed elastic and rubber mountings for the noisiest or vibration-prone components; furthermore, it was powered by an electric turbine driven by the nuclear reactor—rather than being directly connected to the shaft—to prevent vibrations from propagating into the water.
The propellers themselves were angled to avoid generating surface bubbles and to prevent cavitation. All of this was the result of the "Coelacanthe" inter-ministerial program launched by De Gaulle to develop the submarine component of the nuclear deterrent force; this initiative drastically streamlined bureaucracy and enabled the rapid miniaturization of a nuclear reactor and the development of submarine-launched ballistic missiles.
In the mid-1950s, France was already planning the construction of a nuclear submarine—the Q 244—with US support, but the program was cancelled following De Gaulle's rise to power and the deterioration of relations with the United States.
In 1959, France possessed only 440 kg of uranium—barely enough for a land-based reactor—yet a marine nuclear reactor was built the following year as a testbed; in 1964, the Gymnote, a conventional ballistic missile submarine, entered service and contributed to the program's development.
It was not until 1965 that 50% of the defense budget was allocated to the Coelacanthe program.