[Interview] The SSN Perle has arrived at the site of Cherbourg

14 January 2021 Defense Naval Group Fleet services Submarines Story

After its arrival at the site of Cherbourg late December on-board a semi-submersible ship, the SSN Perle was transferred into the Cachin dock, at the heart of the Naval Group site, on Wednesday 6 January. Assisted by French navy tug boats, the Perle was floated into the Cachin launching facility, where repair work will be carried out, and set down on its keel blocks. Since the statement issued by the Ministry of Armed Forces on 22 October on the decision to repair the submarine, the teams from Cherbourg and Toulon have been preparing for the start of this extraordinary task. Franck Ferrer, Programs Director for the Services Division and heading up the works on the Perle project, gives us an overview of the industrial challenges to come.

You are in charge of works on the Perle. How would you describe the mission with which the teams at Naval Group have been entrusted?

In October, the Minister of Armed Forces announced its decision to repair the Perle. Behind this decision lies the major strategic challenge of maintaining the operational capacities of the French navy’s SSN fleet, but with this also comes a show of confidence regarding our industrial capacities.
Of course, we are gauging the scope of responsibilities that are conferred upon us and we must make every effort to minimise the fleet’s downtime in order to allow the French navy to exercise all its missions and its sovereignty.
We have the capacity to live up to the task entrusted to us by our authorities, customers and partners: even though the operation is quite exceptional, the teams at Naval Group master the techniques and skills needed at every stage of the repair work.

How is the repair work organised?

The chosen repair solution consists in “joining” the fore end of SSN Saphir - a submarine taken out of active service in July 2019 and located in Cherbourg for dismantling work - with the aft end of SSN Perle. The repair work will therefore entail a series of cutting, welding and joining operations.
In fact, the activities for this project officially started in November: a team of around 100 employees from Toulon have come up to the Cotentin Peninsula and are working with the teams in Cherbourg to prepare the upcoming cutting work on the Saphir. The teams will now carry out the same repair operations on the Perle. The Engineering Department teams have also been working since last autumn to provide support for all these operations.
Once the cutting work is complete on the Perle and the Saphir in the first quarter, we will then move on to the joining work; but the project does not stop with there. The decks and internal bulkhead will then need to be reconstituted, and of course we will need to bind the numerous connections (around 80 cables, some 20 pipes, etc.)
After all this, the Perle is expected to return to Toulon at the end of 2021 in order to continue its technical stop, which includes the upgrade of its Combat System. The ship’s handover to the French navy is planned for early 2023.

How many people are involved in this shipyard?

Close to 300 Naval Group employees and subcontractors! This project mobilises the expertise of different Naval Group sites, and is a testament to our company’s exceptional know-how. The cutting and welding work on the pressure hull will be carried out by specialists from the site of Cherbourg as they hold the key skills in this field. As for the specialists from the site of Toulon, they will be responsible for the other cutting preparations and the binding of connections. Of course there is also the invaluable contribution of the engineering teams in Toulon, Brest and Cherbourg, who are currently performing studies for the design and change management necessary to perform these repair works.

Is this work the first of its kind?

Carrying out this type of project in these circumstances, i.e. repair work that involves joining the fore and aft ends of two sister ships, is of course a first in the modern history of Naval Group. However, upon closer inspection, our teams already master and are familiar with all the operations that will be performed throughout this project.
Naval Group has already carried out very similar “jumboisation” operations on the Agosta submarines and on the Chilean U2019 submarines. We have also previously completed joining operations for submarine parts that were produced in different shipyards throughout the world, as was the case with the Malaysia Scorpène® program (where several parts were built on the Spanish Navantia shipyard) or the Brazil Scorpène® program (where the fore end of the Riachuelo was manufactured in Cherbourg and then transferred to the Brazilian ICN shipyard to be joined to the aft end).  
Also, we must not forget that joining submarine sub-sections is a highly complex know-how in itself, but setting it up is an essential step in the construction process for a submarine. Our highly-experienced Cherbourg teams master these skills, currently being demonstrated at the site of Cherbourg with the construction of 5 Barracuda-class submarines simultaneously.


Franck Ferrer in front of the SSN Perle during its entry into the Cachin dock on the Cherbourg site