Evolution towards the Barracuda SSN

REQUEST

Submarine Matters has had its first request from a Donor:

    JHM asks - "Can you advise me of the evolution of French submarines that 

    have resulted in the Barracuda SSN?"

RESPONSE

In the long term the design of the Barracuda SSN is based on knowledge accumulated by French designers from more than a century of French submarine building and operating. Basic design ideas also come from broader international submarine community. For example, viewing a surfaced Virginia SSN and talking photos might be very useful when the photos are combined with advanced submarin design computer programs. 

More immediately the Barracuda design descends from SSKs, SSNs and SSBNs built in France over the last 50 years See the Table I have compiled below..

FRENCH SUBMARINE TABLE

Submarine (how many built?)	First Sub Laid Down	Last Sub Commissioned	Some still building?
Redoutable SSBN 6 built	1964	2008
Agosta SSKs 13 built	Early 1970s S 620 for French Navy	2006 for Pakistani Navy	no
Rubis SSNs 6 built	1976
AMETHYSTE rebuild of Rubis	1989 (rebuilding began)	1995
Triomphant SSBNs 4 built	1986	2010
Scorpene SSKs 5 completed	1999 O’Higgins Chile	Sep 2016 Kalvari India	5 x Kalvaris India 4 x S-BR Brazil
SN-BR SSN 1 planned	DCNS designing non-nuclear portion. Brazil building reactor.		Maybe launched in late 2020s
Barracuda SSNs 6 planned	2007	2029 for the last of the six
Shortfin Barracuda Block 1A 12 planned	2028?	2052? Assuming one sub built every two years

The Table indicates that there are a wide range of submarines providing experience for DCNS staff when they designed and build the first Barracuda.

The Barracuda is only the second SSN generation France has produced so it will be far more capable. than the first generation (th Rubis)

Interestingly Brazil envisages developing a submarine reactor and then installing it into Brazil's first nuclear sub (SN-BR).

Note the striking similarity between the Barracuda's sideview (bottom of wallchart) with the  Scorpene's (second from bottom). (Artwork courtesy DCNS Australia)

Clearly the Barracuda's hull and sail/fin are heavily infuenced by design work done for the Scorpene. Using the same external design has advantages in perfecting such critical traits (without reinventing the wheel) as low acoustic signatures and an efficient hydrodynamic design. 

Lessons learned in the operation of reactors in the Rubis and Triomphant submarines would have assisted Barracuda designers. More specifically DCNS designers and French Naval crews are experienced with the K15 reactor. The K15 has also become a mature design - as it is already fitted in Triomphants - and will be installed in the Barracudas. 

Experience with Scorpenes, Triomphants and Rubis also would have assisted Barracuda design in  less obvious features such as:

-  the positioning of on-hull sonar sensors
-  similar combat systems and weapons
-  use of a pumpjets on Triomphants acting as a testbed before using them on Barracudas
-  proving more crew comfort for long missions.

-  quieting technology including from anechoic tiles, elestic mounts to dampen sound and active noise
    control

So clearly Barracuda technology has been evolving from previous submarine designs. Increasing French Naval experience in using this technology contributes to even more evolution.

Pete

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