May 17, 2018

The S-80 Plus to Be the 1st 3,000+ tonne EuroSub Launched

Artwork of the future S-80 Plus courtesy maritimeherald.com. Estimated range/speed 10,000nm at 10 knots snorting. Has 6 x 533 mm torpedo tubes with total of 20? HWT DM2A4 torpedoes, Harpoon missiles, mines. Crew/Complement 32 (+ 8 Special Forces depending on mission)
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In the early-mid 1990s France and Spain jointly undertook a Scorpene S-80 Program. However events and different requirements led to a split between established submarine partners France and Spain.

The end of the Cold War cost cutting ("peace dividend") ended French interest in buying a high specs Scorpene S-80 for French Navy use. Instead France developed and successfully marketed an export Scorpene to Chile, Malaysia, Brazil and India. France relied soley on SSNs (Rubis class and soon the Barracudas) as its attack submarine arm.

Meanwhile Spain relied on its Agosta S-70 SSKs. By the late 1990s-early 2000s Spain wanted a much larger higher specs, second generation AIP, S-80 submarine for Spanish Navy use.

In 2010-2012 Submarine Matters' sitemeter picked up substantial Australian Government interest in considering the future S-80 for Australia's Future Submarine. But then, in May 2013, Navantia announced that a serious weight imbalance design flaw had been identified in the S-80 (under development) which would delay the delivery of the first S-80 submarine Isaac Peral 
(S-81) for the Spanish Navy until possibly 2017.

More specifically S-80 program management inadequacies did fully not take into account an extra 75 to 100 tonnes which prevented the simulated S-80 resurfacing after diving. The extra weight may have mainly been in the Lockheed Martin integrated combat system (sensors, databases and especially weapons (torpedo tubes and about 20 HWT torpedos / missiles).

In June 2013 Spain's Navantia hired US nuclear submarine builder General Dynamics Electric Boat to help solve the S-80's excess weight problem. The solution was that  S-80 needed to be substantially enlarged to achieve buoyancy:

-   from 71m long, and 2,200 tonnes surfaced (see "S-80" diagram above)

-   to 81m long, 3,200 tonnes (surfaced), 3,426 tonnes (submerged) (see "S-80 Plus" diagram above)

With these mistakes and uncertainty Navantia S-80 was excluded from the competition for Australia's Future Submarine (decided in April 2016). But the S-80 now has many characteristics worthy of technology transfer.

Now that the US and Spain have sunk considerable effort in making the S-80 the most modern large SSK approaching launch it may be useful for Naval Group to negotiate a substantial technology transfer from the S-80 to Australia's Future Submarine program. Australia's Future Submarine will need to be larger, of course, sufficient for a crew of 60 + 8 Special Forces. 

A useful source on Scorpene-S-80 history is page 5 of The Market for Submarines Product Code #F673 A Special Focused Market Segment Analysis by: Forecast International (2010?) at http://www.ForecastInternational.com/samples/F673_CompleteSample.pdf.

Pete

3 comments:

Ztev Konrad said...

Some things caught my eye. Based on the numbers and side views you dont add 10m and 1000 t ( surfaced) to correct a lack of buoyancy of 70 t. Ballast tanks would be fairly light weight and are outside the pressure hull. Certainly batteries along the bottom of hull and engine machinery at the rear and torpedoes and their equipment at the bow are heavy.

https://www.marineinsight.com/naval-architecture/submarine-design-unique-tanks-submarine/
They may have buoyancy issues that needed help but they have added a lot more to get another 1000 t surface displacement. As is common exactly what could be classified.

'Back in 2013, media reported that the Spanish Navy’s fleet of S80 submarines was faced with serious delays as it turned out the submarines were 70 tones too heavy to be able to float at all.'
https://navaltoday.com/2016/04/06/navantia-a-step-closer-to-fixing-spanish-submarines-weight-problem/

Anonymous said...

While I tend to agree with you, I would point out that the 70t was to float at all (although I thought it could float but not surface if dived). If I remember correctly, it was not capable of even basic sea trials. They don't load up with all the armaments & supplies at launch & start of first of class sea trials, you work up to it, so there is considerably more weight it has to be able to handle. I would suspect they were considerably more out of wack than 70t to get the sub up to full operational spec. Of course, if you are going to add a plug to a submarine you start to think about what you will put in there & though its said that 'steel is cheap & air is free', its also said 'nature abhores a vacuum', not to mention the 'if we could just add another two meters we could....'. Capability creap is nothing new.

Regards

Ztev Konrad said...

My understanding in these single hull subs the ballast tanks are at either end, outside the pressure hull in free flooding areas. Minor tanks can be inside hull sometimes at centre of gravity or nearer torpedo tubes.
It wouldnt really be necessary to cut the pressure hull on the S80 to increase the volume of the outside ballast tanks, and Im sceptical of general media reports saying the submarines cant surface after diving - although that may be true from its test depth. Much more likely for the cutting the hull and lengthening is the problems for the AIP system. Lengthening the hull and creating greater internal volume only increases the volume of ballast tanks required to allow the sub to sink, so would create the reverse problem , a submarine than cant sink below the surface.