The SSN was in dry dock, undergoing a major overhaul at Toulon naval base in Southern France, where all French Navy Rubis-class submarines are home ported.
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.
There was no nuclear fuel on board , this having been removed as part of the technical shutdown. There were no weapons such as missiles or torpedoes, ammunition and no batteries on board either.
The damages sustained by Perle may be significant given the duration of the blaze. Should Perle not be able to return to active duty, the consequences may be serious for the French Navy as it would leave a large capability gap affecting the French submarine force as well as the security of the French nuclear deterrence.
This would leave the French Navy with only 4 operational SSNs. The Rubis-class SSN Saphir, second boat of the class, was decommissioned in July 2019. The next class of SSN, the first ship-in-class Suffren , which started sea trials recently, won’t be fully operational until 2021.
Following her inspection of the Perle, the french minister of armed forces said most of the ship’s equipment such as sonars and combat systems were not aboard and are therefore intact. She added that should the Perle be fixable, everything will be done to repair it.
The U.S. Navy had a similar experience dealing with a fire aboard the Los Angeles class submarine USS Miami in 2012. That fire, which was also during an overhaul, lasted 12 hours and caused so much damage that the boat had to be written off. That fire was started deliberately by a dockyard worker hoping that the alarm would get him off work early.