SNA Perle lives again: Meet France's new 'Frankensub'

Severely damaged by a fire in 2020, France's nuclear attack submarine, the SNA Perle, was thought lost. But major "submarine surgery" has saved her from the scrapyard.
Christopher McFadden
frankensub-sna-perle.jpg
Image of the new "frankensub" SNA Perle.

Naval Group 

The French Navy has officially received what has been termed a "Frankensub" submarine. A conglomeration of the front and back of two formerly separate submarines, the new submarine is a marvel of engineering and very novel indeed. Overseen by Naval Group, the "new" jerry-rigged submarine, the SNA Perle, should remain in active service until around 2028.

But why was this strange engineering project undertaken in the first place? Before we get to that, here is a little history on the submarine(s) in question.

Frankenstein's monster ship

One of the two parts came from the ship of the same name as the new "merged" boat, the original SNA Perle. This submarine was a first-generation nuclear attack vessel of the French Navy. She was also the sixth and final vessel in the Rubis-class. Construction began on March 27, 1987, and the submarine was launched on September 22, 1990. It became operational on July 7, 1993.

In June 2020, the French Navy experienced a significant incident where the SNA Perle, a Rubis-class nuclear attack submarine, caught fire while in drydock in Toulon. The fire caused extensive damage to the forward section, and it was almost deemed necessary to discard the submarine. However, the French government opted for a solution that was nearly as ambitious as constructing an entirely new one.

The Fleet Support Service oversaw the Naval Group's contract to transport the damaged submarine to Cherbourg for repairs and refueling. The undamaged aft section of the Perle was also modernized, and the firefighting foam was cleared out. Additionally, the Naval Group removed the aft section of the decommissioned Rubis-class SNA Saphir, which had been retired in 2019.

The next step was the most difficult, as New Atlas explains. The Naval Group attempted to combine the front section of Saphir with the back section of Perle. Although it may seem like a straightforward task, in reality, it was a complex engineering challenge. Even if two submarines belong to the same class and have the same design, every vessel is a distinct creation, as shipyard experts and engineers encounter numerous issues that must be resolved on the spot to ensure the boat operates optimally.

A tricky task

Joining the two sections required techniques akin to an organ transplant, with the added challenge of withstanding immense pressure from the ocean depths. The process involved advanced cutting and welding methods and meticulous alignment of the hulls. Even a minor deviation could have catastrophic consequences.

Next came the "fun" task of rebuilding the interior decks and linking hundreds of pipes, cables, wires, and various systems. The Naval Group reported that this required the efforts of 300 individuals, 100,000 engineering hours, 2,000 updated plans and design documents, 250,000 industrial hours, 2,000 electrical connections, and one million hours of maintenance and repairs.

An impressive feat of engineering, we think you'll agree.

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