April 13, 2021 – Naval Group received the French Minister of the Armed Forces, Florence Parly and the French Chief of Navy, Admiral Pierre Vandier, at its Cherbourg site. They toured the shipyard where the nuclear attack submarine (SSN) Perle is currently being repaired. The Minister of the Armed Forces and Ambassador of Australia Gillian Bird also met with the Franco-Australian teams working on the Australian Future Submarine program.
“Naval Group and its industrial partners are fully committed to enable to allow the French Navy to recover as quickly as possible the potential of its six nuclear attack submarines. The success of the repair works on the Perle owes a lot to the know-how and professionalism of the Naval Group teams involved and we are proud to offer these unique skills at the service of a challenge whose scope we fully appreciate” declared Pierre-Eric Pommellet, Naval Group Chairman and CEO
The Perle repair and transformation
The repair and transformation works on the SSN Perle that has been heavily damaged last June is a totally new challenge. Five months after the beginning of the work, the undamaged back of the Perle will be assembled with the bow of the Saphir. The latter was withdrawn from service in July 2019.
The hybridisation of two submarines is both an innovative and controlled operation. Different steps included:
- The cutting of the two submarines Perle and Saphir, respectively in February and March
- The very accurate movement and alignment of halves of the submarines on “walkers” at the beginning of April
- The welding of the thick hull of the two half-submarines, followed by the reconstruction of the inner decks in the junction area
- The splicing of hundreds of cables and manifolds
Around 100, 000 hours of engineering studies are underway to update some 1,4 meter long area added to the submarine) and the splicing area of thecables and pipes that run through the submarine from bow to stern. An important layout work of the junction area has been carried out using a 3D digital model of the Perle, realised by a team of five design integrators. hey created a digital twin of the area, in which they defined the pipe and cable routes, the supports that will hold the pipes and cables, etc. This 3D model will also allow the electricians and pipe fitters to rehearse their movements in virtual reality before carrying out the operations on board.
Once refurbished, the SSN Perle will be stationed at the Toulon naval base. Naval Group will start afresh at the end of 2021 the Periodic Interruption for Maintenance and Repair (PIMR) and finally the upgrade of the submarine.Since the French Minister of the Armed forced decided on October 22nd to proceed with the SSN Perle repair, all the milestones have been reached. The Perle was transported from Toulon to Cherbourg. She was positioned on the launching device at the beginning of January 2021 and the preparation works for the thick hull cutting have started with the decks, bulkheads and electrical cables cutting. The thick hull cutting was a sensitive step perfectly mastered.
This large-scale project represents more than :
- 300 people and more than 20 skills;
- 100, 000 hours of engineering work with the creation and the update of more than 2,000 drawings and design documents;
- 250, 000 hours of industrial work shared between cutting tasks, desk and internal partitions reconstitution, welding and junctionning;
- More than 120 electric cables that will be reconnected, which is equivalent to more than 2,000 connections;
- The PIMR works that will take place in Toulon and that will represent more than one million hours of work
The nuclear attack submarine Perle is the last of six Rubis Class submarines, admitted to active service in 1993. Once renovated, she will be 1,4 meters longer, a volume specifically created to integrate the junctions box necessary for the splicing of electrical cables in particular. This extension will also provide two new living quarters, which will save space for the crews.
The Rubis Class will be progressively be replaced by the Barracuda submarines. The first of series, the SSN Suffren, was delivered to the French Navy in November 2020. The construction of the Barracuda submarines continues with 5 submarines under construction at the Cherbourg site.