October 8, 2022

News About French Barracuda SSNs

The French Barracuda SSN program, after some years of delay is finally reaching maturity. Delays were most officially due to revisions of the future Barracuda’s roles combining multiroles suiting the relative peace after 1992 with the end of the West vs Russian First Cold War. However a greater design emphasis (perhaps mainly in the combat system) on anti-submarine warfare may have emerged with the Second Cold War from around 2014 with a new Russian threat, as well as (for the first time) a Chinese threat. Also I suspect that the Barracuda’s K15 reactor needed some extra miniaturisation from its larger K15 dimensions in the French Triomphant-class SSBNs and in the French nuclear carrier Charles de Gaulle. 

I am advised by a French friend that first commissioned Barracuda SSN, French Ship (FS) Suffren (photo above) recently visited the UK’s largest nuclear submarine base HMNB Clyde at Faslane, Scotland starting September 22, 2022. Clyde (photo below) is of course Britain’s SSBN base and I believe British SSNs also frequently visit.

Other news is that the second Barracuda, Duguay Trouin, was launched on September 9, 2022. Its K15 reactor (with 150MW (thermal) power) has gone “critical” (ie. nuclear fuel activated and steam produced). 

Six Barracudas have long been planned, but with the resurgent Russian threat there are rumours that a 7th or even 8th Barracuda might be built.

9 comments:

Anonymous said...

Regarding the thermal output of the K15 reactor, the CEO of TechnicAtome mentioned that it's not 150MW thermal. It's less.

Anonymous said...

Be careful not to confuse Thermal and Mechanical /Electrical power ..
150 Mw T means typically 35 to 40 Mw E or about 50 000 HP at most (Thermodynamic Cycle and I Hp is 736 W).This is what is mostly reported in the open press . Exact top speed and actual power is not public
Remember this 5000T sub is sailing at 25+ knots submerged.The defuncts Aus Barracuda were deemed to run at 7Mw ..power moves with the square of the speed roughly..

Pete said...

Hi Anonymous @Oct 8, 2022, 10:52:00 PM

If, as you say, "not 150MW thermal. It's less." Then how many MWs is the K15's THERMAL power?

++++++++++++++++++

NOTE:

French website https://fr.wikipedia.org/wiki/K15 translates to:

"The K15 is a type of pressurized water reactor...with a thermal power of 150 megawatts

designed by the TechnicAtome company in the early 1980s to equip the Le Triomphant class nuclear submarines."

Anonymous said...

Pete

Thanks. Whilst in the past I have expressed a strong preference for the RAN to acquire British Astutes for its SSN under AUKUS, recent announcements have modified that view on my part. These are:
- UK Def Sec Ben Wallace confirming Astutes were going out of production and proposing a joint UK/US/AUS SSN under AUKUS. This is presumably SSN(R). That carries a cost and delivery time risk, with presumably first delivery to the RAN not before 2040.
- US Rear Adm Mike Papalano advising that Australian SSN production would strain the US shipyard capacity. So again, presumably no prospect of Virginias before 2040 either.
- Reporting that France Macron) had offered to build the RAN four SSKs in September. Building the first 2 or 3 SSNs of an RAN Suffren program would be far more useful, but the willingness of France to still allocate shipyard capacity to an RAN build is significant.
https://www.navyrecognition.com/index.php/naval-news/naval-news-archive/2022/september/12202-france-offers-four-submarines-to-australia-despite-the-stab-in-the-back-of-aukus.html

Given the constraints on the UK and US options we are now in the world of pragmatic decisions. Any UK/RAN partnership for a new design (SSN(R)?) is sure to be slower and more costly than building a smaller existing design that is already in production.

Therefore in my view if France is willing to supply Australia 2 or 3 Suffren class SSNs built in Cherbourg now, desirably fitted with the US combat system and weapons as was intended for the Attack Class, Australia should take the deal. Further, if Naval will build the remaining 8 or so SSNs at ASC with French supplied reactor compartments, again Australia should take the deal.

I note France double crews Suffrens and the crew size is similar to Collins. Three double crewed Suffrens could largely replace the Collins class in operational terms. If this could be done before 2035 it would save the RAN $6 billion on the LOTE project. There would still be a large crew training task, but that is true for any option.

GhalibKabir said...

I think it might be a typo as 150 MWth is usually available max as 25 MWe to 30 MWe using the rough rule of thumb as max 1/5-1/6 thermal power becoming electrical power in marine propulsion plants.
I remember reading this in one of Peter Lobner’s papers

Pete said...

Hi Anonymous @Oct 9, 2022, 9:04:00 PM

Yes the French SSN variations will be aired and UK-US options developed in my next blog "SubmarineMatters2..." starting next week. Building SSNs in Adelaide being a priority...

Other milestones in SubmarineMatters2 will be many comments on the:

- 1 November 2022: Houston/Smith Australian Strategic Defence Review "Interim Big Picture" Report

- 1 February 2023: Australian Strategic Defence Review FINAL REPORT

- March 2023: Australian Nuclear Powered Submarine Taskforce REPORT

- May 2023: Albanese Government's Initial Budgeting for the Australian Nuclear Powered Submarine Program

Cheers Pete

Pete said...

Hi GhalibKabir @Oct 9, 2022, 10:08:00 PM

Page 206 of Peter Lobner's "Marine Nuclear Power 1939 – 2018_Part 4_Europe & Canada" at https://secureservercdn.net/198.71.233.183/gkz.aeb.myftpupload.com/wp-content/uploads/2018/07/Marine-Nuclear-Power-1939-2018_Part-4_Europe-Canada.pdf

gives the K15's "Integral PWR rated at 150 MWt."

Indeed an SSN's electrical output (MWe) derived from its reactor and electical motor conversion is a more important figure than MW Thermal(t)/"Integral Power".

- with the Barracuda SSN's 25 MWe to 30 MWe being for Propulsion and Hotel Load.

Cheers Pete

Anonymous said...

Here is a link with the interview with TechnicAtome:
https://www.pressreader.com/france/la-tribune-france/20200618/281621012585463

Relevant quote : "Le réacteur du Suffren est moins puissant que ceux de la génération précédente qui équipe le porte-avions et les SNLE de la génération du Triomphant".

Conclusion :
Suffren's K15 has les than 150MW thermal output.

Pete said...

Thanks Anonymous @Oct 13, 2022, 6:27:00 PM

Relevant quote : "Le réacteur du Suffren est moins puissant que ceux de la génération précédente qui équipe le porte-avions et les SNLE de la génération du Triomphant".

Translates as "The Suffren [K15] reactor is less powerful than those of the previous generation which equip the aircraft carrier [Charle de Gaulle's 2 x K15s] and the [K15 of the] SSBNs of the Triomphant generation."

Pete Comment

I suspect one reason is that the Barracuda/Suffren's reactor is smaller/less tall (as it is has to fit in a smaller SSN hull) than the carrier Charles de Gaulle's and Triomphant SSBN's K15(s).

The more importan comparative measure is the conversion from mechanical/thermal to Electrical energy. With:

- https://en.wikipedia.org/wiki/French_aircraft_carrier_Charles_de_Gaulle 2 x K15 reactors = 2 x 30.5 MWe + 61 MWe

- Triomphant SSBN https://en.wikipedia.org/wiki/Triomphant-class_submarine 1 K15 = 30.5 MWe

while

Barracuda/Suffren's https://en.wikipedia.org/wiki/Barracuda-class_submarine_(France) K15 works out to 2 x Turbo-generator groups: 2 x 10 MW = 20 MWe. But does this smaller K15 also have a non-propulsion "Hotel Load" figure of 10.5 MWe or less?

Cheers Pete