With direct relevance to the Netherland's Walrus Replacement issue, many other submarine and battery issues, Locum has provided this very interesting, lengthy comment (set out in Parts 1. and 2.):
Locum commented (with addition of hyperlinks by Pete) on February 7, 2021 7:04am:
Part 1:
Our planet is now in the conversion phase from a
geo-political uni-polar [one Superpower, the US] situation towards a multi-polar
world. Currently and in the future, we will face more threats, which can be
technically equal or superior. The threats will also be more diverse, more
complex and unpredictable.
In order to cope with this rapidly changing world,
Darwin's Law becomes more important. The species that adapts the best, will
have the most chance at survival.
Submarines are changing considerably to, because of technological developments like: AIP, drones, new types of batteries, and increasing automation.
To give a submarine more potential of adaptation, or
flexibility, the new generation subs need more multi-role capabilities. The new
gen. sub must be able to operate in 'brown water' and 'blue water'.
Considerably more max. diving depth, range, endurance and speed. All to cope
better with nuclear propelled subs and operations further away.
Surface ship design is ruled by the "iron
triangle" of: speed - range - payload.
Submarine design has to do with the "iron diamond": speed - range - payload - diving depth.
- An AIP will give much more endurance, but will also
add roughly 5 meters to submarine length. During transit, the AIP is not
working and thus will eat into your payload and range.
- The payload will consist of bigger and better
sensors, more drones and Special Operation Forces (SOF, commandos). Because
they will play structurally a bigger role in the new boats.
Anti Surface Warfare (ASuW) and Land Attack
capabilities are becoming more important too, so add more cruise missiles in
your torpedo room or ... add a VLS. Not only for cruise missiles, but also
(quasi) ballistic weapons.
If you want to operate your submarine not only in
the cold North-European waters, but also in the (sub)-Tropics (with saltier
water) your boat needs bigger trimming tanks.
Yes, further automation results in smaller crews, but
significantly longer range and endurance asks for relatively bigger crews to
prevent exhaustion.
In January 2015, the Netherland’s Damen Schelde Naval Shipyard CEO Heijn van Ameijde, announced the submarine cooperation with Saab-Kockums. During that announcement he noted the structural shift in the submarine market, especially in Asia, towards more 3.000 - 3.000+ tonnes submarine types.
If we want to believe the Saab-Kockums marketing.
Than just stretching the A26 till a maximum of over 80 meters will serve that growing
market segment.
The standard A26 has already an unfavourable Length/ Diameter (L/D) ratio of 10.3. The Kilo, TR-1700, Walrus, Type 212 and Dolphin's have a very good L/D ratio of approx 8. That's close to the optimal submarine L/D ratio of 7.0.
__________________________
- a pressure hull (pink and of smaller diameter) and the
- outer hull (lighter steel and larger diamenter - built for easier movement through water).
The diagram is by "wispywood2344" and was in this article of September 6, 2016. A larger version is at wispywood2344's blog here .
Locum continues with Part 2. posted February 7, 2021 7:48am.
Originally, at the end of the 1990s, the Spanish Navy
wanted to buy the Scorpene.
A relatively cheap export boat, with moderate
performance and capabilities and optimised for littoral / 'brown water'. In
2002 - '03 the Spanish DoD ran an assessment of the future geo-political
reality and threats. It concluded “we” [Spain and/or the Netherlands?] do not need a defensive coastal water boat, but an ocean-going defensive and
offensive capable (power projection) sub.
It would have, significantly higher range of 10,000 –
12,500nm, deeper max. diving depth, cruise missile capability. This all means a
much higher price.
Spain’s Navantia came up with a quite compact
solution. A sub 2,200 tonnes (surfaced), 2,426 tonnes (submerged), total length
of 71.05m, diameter of pressure-hull is just 7.30m.
The Netherlands’ Walrus class is already a cramped
design. It is by comparison: (submerged) 2,800 tonnes, 67.7m length and a max.
diameter of 8.40m. Both are propelled by 3 side-by-side diesel generator sets
and built in Marel? steel, equivalent to HY-100.
The 2,400 tonnes (submerged) and 68.6 meter long Israeli
Dolphin 2s, which are designed to the same doctrine as the S-80, have 3 x MTU
16V 396 SE84s as well. This is because of the higher safety margin, needed in a
long range sub.
Try to squeeze 3 x MTU 396's or 3 x MTU 16V 4000's,
depending on version: 1.69 – 1.80 m. wide, in
an officially 6.80 meter wide pressure-hull [of an A26?]. Hhmm, mission impossible.
The Argentinian TR-1700 surfaced 2,140 tonnes and submerged 2,336
tonnes. Has a length of 65.93m; a diameter of 8.36m. Max. range is 12,500nm,
with a max. speed of 25 knots. The TR-1700 was the fastest operational diesel-electric
sub, propelled by 4 MTU 16V diesels. The TR-1700 had a crew of 37, while the
Dolphin's have 35 crew + 10 extra crew or SOFs.
The Walrus has a crew of 50, while the (original) S-80 has a very compact crew of just 32. The S-80's Combat Information Center (CIC, command center) is cramped. In this CIC there is certainly no room for extra (drone) consoles. In this tight boat concept, there is also no spare space for extra crew, Special Operations Forces members, or drones. Yes, the S-80 Plus submarine got stretched from 71.05m to 80.81m, but that's to restore the buoyancy of the too heavy boat. The L/D ratio went from 9.73 to a very high 11.07. Originally, the S-80 should had a theoretical max. speed of 22 knots, but for the S-80 Plus it is calculated at 19 knots.
So technically and commercially it's better for a
submarine manufacturer to set up a 3,000 tonnes sub product line, which is not
a stretched version of a littoral submarine, but a shortened variant of a
bigger boat. A shorter version of the Type 216 was the favoured choice of the
Singaporean Navy. Unfortunately, because of the quickly growing Chinese threat,
they wanted their new submarines ASAP. Singapore also didn't want to bear the
risks of being a the first customer of an entirely new Type 216 sub.
Lithium-Ion batteries
Scientific research concluded that statistically
seen, sooner or later a Lithium-ion Battery (LIB) equipped submarine will catch
fire. LIBs have been used safely underwater already for 25 years [Pete comment:
maybe or maybe not]. However, it's the application of much
larger numbers of LIBs cells in submarines and over a long timespan (25-30
years) that makes the statistical chance at a Li-Ion battery fire realistic.
Lithium Iron Phosphate (LiFePO) batteries are significantly more stable than other LIBs, in other words: as safe as Lead-acid Batteries (LABs). Compared to LABs, LiFePO batteries have also a 9 % lower specific weight.
The lifespan of LiFePO batteries is longer (more discharge cycles) and their re-charge time is shorter.
The LiFePO manufacturer for TKMS is SAFT [Pete comment: see many
mentions of SAFT and some of TKMS in this article]. First LiFePO batteries for rigorous
defense applications, were introduced by SAFT in 2009.
LiFePO batteries will not only find application in Type 212CDs, but also 212CD Es, Type 214s, etc.
Locum
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