February 13, 2018

Japan Increasingly its Submarine Propulsion (Diesels & Motors), Soryu TABLE

Submarine Propulsion in 7 lines. Air through snorkel is sucked into the Diesel Engine. Combustion from [spark and?] compressed diesel fuel produces the Diesel's mechanical power - Which then drives the Generator (which changes mechanical energy into electrical energy). The electricity and drives the Electric Motor which charges the Batteries. Diesels/Generator/Electric Motor/Magnets to rotate propeller to produce (about) 8-12? knot snorting speed. OR Batteries/Electric Motor/Magnets producing the silent running speed which is above 6 knots.
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Following Submarine Matters Possible Motor Modifications for Australia's Future Submarine, February 9, 2018 Anonymous kindly commented on February 5, 2018 (with a bit of further translation by Pete):

The Soryu Mk 2 (at 27SS in the Table below) importantly will have:

(A)  a modified propulsion motor (designated “SMC-8B”) [1]
(B)  accompanied by Lithium-ion Batteries (LIBs). LIBs provide various benefits such as a low 
       indiscretion ratio (IR) [a lower the ratio of time spent at periscope depth snorting to time   completely submerged 
(C)  flexibility of operation and high speed performance submerged and
(D)  12V25/25SB diesels used in the current Soryu Mk 1 Soryu Mk 2 prior to use of 12V25/31S in Soryu Mk 3.

The newly modified propulsion motor (designated “SMC-8B”) will benefit from the more powerful diesel and the more electrically powerful LIBs quick charging of LIBs in order to achieve flexibility of operation and high speed performance submerged. In Soryu Mk 1, low speed performance is emphasized because of low effective capacity of LABs. 

In the Soryu Mk 2, higher silent (6> knots) speed performance will be emphasized, because of drastically improved LIB and motor capacity. This allows higher silent speed fully submerged for a much longer period. 

In other words, the main objective of the SMC-8B is the improvement of maximum silent speed. Key factors will be optimized to reduce vibration/noise, in Anonymous's opinion. As result, maximum speed from point to point somewhat changes as shown in [2] and [3]. Even a tiny improvement in the existing 5 minute duration of the 20 knots maximum speed would require a much more powerful engine. Anonymous does not think such a tiny improvement has meaning in actual operation. [4]

[1]       Budget of Japanese Ministry of Defense (MoD)

Soryu Mk 1s have propulsion motor SMC-8 and Mk 2s have SMC-8B (where the B means first revision) see Table below. The degree of revision can be measured by the first year cost which is the cost of new equipment and so on in the first year.  In SMC-8B, the first year cost was budgeted suggesting that SMC-8B experienced huge modifications or SMC-8B is actually a new model. So overall the last Soryu Mk 1 (26SS with SMC-8) costs ¥51.7B FY2014 (see Table below). Then the cost for the first Soryu Mk 2 (27SS) jumps to ¥64.4B FY2015 of which the development and unit costs of the first SMC-8B are a part.

[2]       “FY2014 Annual Report on Life Cycle Cost Management”, Equipment
Procurement and Construction Office, Ministry of Defense (MoD), page 78, Tabale 2. The maximum submerged speed of 26SS (Soryu Mk 1 with Lead-acid Batteries (LABs) + AIP) and 27SS (Soryu Mk 2 with LIBs) are both 20 knots.

[3]       Using English wikipedia websites - LIBs have a greater average charge and discharge efficiency 80%-90% (see LIB sidebar) compared to LABs with a lower average in the 50%-95% (see LAB sidebar). A Soryu Mk 2 submarine using LIBs, like a Soryu Mk 1 submarine using LABs both will not exceed 20 knots.

[4]       Additional comments by Anonymous of February 13, 2018. Japanese submarines are not equipped with reduction gear. Their speeds are electrically adjusted. The DC motors of Oyashios and AC motors (PMSM) of Soryus have different adjustment systems. In the Soryu Mk 1 (SMC-8), maximum silent speed is greater than 6 knots. This may correspond to the maximum operating output of a small rotor. In the Soryu Mk 2 (SMC-8B) an increased maximum silent speed for a longer period is expected.

Since 20 knots for 5 minutes is a performance limitation of the SMC-8, achieving 20 knots for an hour would require major modifications such as an increased cooling system, bigger rotor and stator, reinforced bearing and shaft. The speed of a submarine is proportional to cubes of output of the propulsion motor. A 10% increase in maximum speed (from 20 knots to 22 knots ) would need a 33% increase in output (from 5.9MW to 8MW). This requires major modifications. These modification may cause additional vibration leading to greater submarine noise.

Achieving a higher silent speed for a longer time within the framework of the submarine's current output is a more realistic objective.

TABLE SORYU & Oyashio Program as at March 142018 

SS
No.
Diesel Type
Motor
Build No
Name
Pennant
No.
MoF approved amount ¥
Billions FY
LABs, LIBs, AIP
Laid Down
Laun
-ched
Commi
ssioned
Built
By
8105 Oyashio
SS-590/ TS3608
¥52.2B FY1993
LABs only
 Jan 1994
Oct 1996
Mar 1998
 KHI
6SS-15SS
Oyashios 
10 subs
2 Toshiba motors
SMC-7?
8106
-8115
various
SS-591-600
¥52.2B per sub
FY1994-FY2003
LABs only
 15SS Feb
2004
15SS
Nov
2006
15SS
Mar 2008
 MHI
&
KHI
16SS
Soryu Mk 1
12V25/25SB
SMC-8
8116
Sōryū
SS-501
¥60B FY2004
LABs + AIP
Mar 2005
Dec 2007
Mar
2009
MHI
17SS
8117
Unryū
SS-502
¥58.7B FY2005
LABs + AIP
Mar 2006
Oct 2008
Mar
2010
KHI
18SS
8118
Hakuryū
SS-503
¥56.2 FY2006
LABs + AIP
Feb 2007
Oct 2009
Mar
2011
MHI
19SS
8119
Kenryū
SS-504
¥53B FY2007
LABs + AIP
Mar 2008
Nov 2010
Mar
2012
KHI
20SS
8120
Zuiryū
SS-505
¥51B FY2008
LABs + AIP
Mar 2009
Oct 2011
Mar
2013
MHI
No 21SS
No 21SS built
22SS
8121
Kokuryū
SS-506
¥52.8B FY2010
LABs + AIP
Jan 2011
Oct 2013
Mar
2015
KHI
23SS
8122
Jinryu
SS-507
¥54.6B FY2011
LABs + AIP
Feb 2012
Oct 2014
7 Mar 2016
MHI
24SS
8123
Sekiryū
SS-508
¥54.7B FY2012
LABs + AIP
KHI
25SS
8124
SS-509
¥53.1B FY2013
LABs + AIP
22 Oct 2013
12 Oct   2016
MHI
26SS
end of SMC-8s
8125
Shoryū
SS-510
LABs + AIP
2014
6 Nov 2017
Mar 2019?
KHI
27SS First
Soryu Mk 2
12V25/25SB
first SMC-8B
8126
SS-511
LIBs only
2015
2018?
Mar
2020
MHI
28SS  Second
Soryu Mark 2
12V25/25SB
SMC-8B
8127
SS-512
¥63.6B FY2016
LIBs only
2016?
2018?
Mar 2021?
KHI
29SS First Soryu Mk 3
SMC-9?
8128
?
¥76B FY2017
LIBs only
?
?
2023?
MHI?
30SS Second Soryu Mk 3
12V25/31S
8029?
?
¥71.5B FY2018
LIBs only
?
?
2024?
KHI?
Table from information exclusively provided to Submarine MattersLABs = lead-acid batteries, AIP = air independent propulsion, LIBs = lithium-ion batteries. ¥***B = Billion Yen. MHI = Mitsubishi Heavy Industries, KHI Kawasaki Shipbuilding Corporation of Kawasaki Heavy Industries. On Feb 13 2018 Diesel and Motor types were added.
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Anonymous and Pete

2 comments:

Anonymous said...

Hi Pete

Japanese submarine does not equip with reduction gear, and its speed is electrically adjusted. DC motor of Oyasho and AC motor (PMSM) of Soryu have different adjustment system. In Soryu MKI (SMC-8), maximum silent speed which is bigger than 6knot/h, may correspond to maximum output at single operation by small roter. In Soryu MKII (SMC-8B),incleased maximum silent speed for longer period is expected.

Since 20knot/h for 5min is limitation of SMC-8 as a machine, achieving 20knot/h for 1h requires big modification such as increased cooling system, bigger roter and stator, inforced bearing and shaft. Speed of submarine is propotional to cubes of output of then propultion motor, and then 10% increase in maximum speed (from 20knot/h to22knot/h) needs 33% increase in output (from 5.9MW to 8MW), and this also requires big modification. These modification may cause additional vibration.

Achieving higher silent speed for longer time at least within the framework of current output is most realistic.

Regards

Peter Coates said...

Hi Anonymous

Thanks for your suggested changes.

I'll alter the text accordingly tomorrow.

Regards

Pete