Rubis-class SSN Perle suffered damages during a fire in June 2020.
According to the French Navy, the SSN Perle completed its period of “unavailability for maintenance and repairs” (dubbed “IPER” in French) on June 30, 2023, following successful sea trials, This means that the submarine is back in the operational cycle of the French Navy and able to deploy on missions.
The submarine started a refit period back in 2019. A fire broke out in June 2020 while the submarine was in dry dock in Toulon naval base. Following unprecedented repair work, carried by Naval Group at its submarine shipyard in Cherbourg, the SSN resumed its “IPER” in Toulon at the end of 2021. It began its dockside trials after leaving the dry dock on November 10, 2022. At sea trials began in May 2023. The start of the sea trials was marked by the first static dive carried out on May 22, in the harbor of Toulon.
During its IPER, Perle received a number of upgrade. The SSN is now capable of implementing the F21 heavyweight torpedo initially designed for Suffren-class submarines. During its operational qualifications, the crew will fire a practice F21 torpedo.
Pele now has an operational potential until 2028, the French MoD said in a statement released today.
About Perle‘s unique repairs
Perle was transferred from Toulon to Cherbourg in December 2020. During the fire which lasted 13 hours, the high temperature altered the the quality of the submarine’ steel in the forward section of the hull. In order to “save” the submarine, the forward section of Perle was cut off and the forward section of another Rubis-class SSN, the Saphir, was welded back to Perle‘s aft section. The Rubis-class SSN Saphir (second boat of the class) was decommissioned in July 2019.
The “transplanting” operation of the two submarines took place in the following way:
- cutting of the two submarines – January to March 2021
- movement and alignment of the submarines halves – May 2021
- welding of the thick hull
- splicing of hundreds of cables and manifolds (130 electrical cables and 70 hydraulic pipes had to be reconnected)
This operation was a first in France. The decision to proceed with this solution was taken following careful analysis by the technical experts of Naval Group, the DGA and French Navy.
About Perle’s fire
For the record, on June 12 2020, at 10:35 am, a fire broke out in the fore zone of the Rubis-class SSN Perle in a basin within the naval base of Toulon. The blaze was put out at 12:50 am the next day, after more than 14 hours of a fight that mobilized a hundred firefighters and more than 150 sailors in support.
Perle’s fire left a capability gap affecting the French submarine force as well as the security of the French nuclear deterrence. The French Navy is left with only 4 operational SSN. The next class of SSN, the first ship-in-class Suffren , won’t be fully operational for a few weeks still.
About French Navy Rubis-class SSN
According to Covert Shores’ World Submarines Recognition Guide, The first of the six Rubis-class submarines was commissioned in 1983 and the final one in 1993. They are the smallest nuclear-powered submarines in the world with a length of just 73.6 meters and a submerged displacement of 2,600 tons.
From the beginning, the boats were disappointingly noisy and failed to achieve some of the performance objectives (such as top speed). As a consequence, the French Navy and industry embarked on the Amethyste upgrade program in 1989. AMETHYSTE stand for Amélioration tactique, hydrodynamique, silence, transmission, écoute (Silent Acoustic Transmission Tactical Hydrodynamic Improvement). It brought a number of upgrades including a major change to the hull form and bow. By 1995, all six boats of the class had been upgraded. Rubis-class submarines are now regarded as very capable boats. The French Navy deployed the Emeraude all the way to the Pacific Ocean earlier this year. It also conducted a South China Sea patrol.
Rubis-class submarine specifications
- Displacement: 2,400 tons surfaced; 2,600 tons submerged
- Length: 73.6 meters (241 feet)
- Beam: 7 meters (25 feet)
- Speed: 18 knots surfaced; 25+ knots submerged
- Depth: 300 meters (984 feet) operational
- Propulsion: K48 pressurized water reactor (64,000 hp); 2x turbo-alternators; 1x 9400 hp electric motor, one shaft
- Complement: 70 sailors
- Weapon systems: 4x 533mm torpedo tubes for 14x F17 torpedo (F21 aboard Perle) or 14x Exocet SM39 anti-ship missiles
- Sensor systems: DMUX-20 active/passive sonar; DSUV-62C towed array
