Perle was transferred from Toulon to Cherbourg in December 2020 in order to repair severe damages the submarine sustained following a fire which took place in June 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)
“Today Perle is back in the state she was in a few hours prior to the fire. We have erased the damages caused by the fire. As soon as the boat is back in Toulon, the major overhaul will resume […] Sea trials will begin at the end of 2022 and Perle will be operational again in the first half of 2023.”
French MoD spokesperson Hervé Grandjean
Perle is expected to remain in service until the 2030ies. During the upcoming overhaul, the flank array sonars will be upgraded.
Cutting, hull welding and connection work was carried out at the Naval Group submarine shipyard in Cherbourg Normandie. Perle is now on its way back to Toulon naval base (aboard the Rolldock Storm vessel) where Naval Group will resume the overhaul of the submarine which was interrupted in June 2020.
Contacted by Naval News, a Naval Group spokesperson said “all critical stages of the repair work have been completed. We will be able to resume work on the overhaul in Toulon for delivery in 2023”.
About 300 personnel took part in the repair work, including 100 from the Naval Group site in Toulon. They were transported to the Cherbourg shipyard by plane on a weekly basis. The repair took a total of 350,000 hours overall (including 100,000 hours of studies).
1.4 meters longer, 68 tons heavier
Perle now features an additional section and is therefore longer by approximately one meter. This is because the two “half hulls” were not cut at the exact same spot, in order to facilitate the connections of internal equipment (such as pipe and cables). The submarine’s displacement is increased by 68 tons. The additional section provides the crew with two new compartments aboard the submarine.
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 (South of France). 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 leaves 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 or 14x Exocet SM39 anti-ship missiles
- Sensor systems: DMUX-20 active/passive sonar; DSUV-62C towed array