Japanese Political, New Soryu and Torpedo Issues

Comments by Japanese friends, in July and August 2016, provide a whole body of insights and details little discussed in the submarine Anglosphere.

New Japanese Defence Minister Inada. Nakatani demoted?

In early August 2016 Japan’s conservative Prime Minister Abe appointed a like-minded conservative as Defence Minister. She is Tomomi Inada. Too early to tell what impact she will have. She is considered highly nationalist by China and some other regional neighbours. “Many political observers in Japan believe that Abe is grooming Inada to be his successor…”

I don’t know if former Defence Minister Nakatani has been demoted? If so, was it due to not selling the sub to Australia?

Sub size and sonars

Gleaned from Comments (27/7/16 12:05) from ex-Vice Admiral, Masao Kobayashi (SHIPS OF THE WORLD, from 2016, No.9) along the lines that generally the larger the submarine the more powerful and effective its sonars. This places larger, reactor powered, submarines at the top of the sonar effectiveness tree (particularly for more commonly used passive sonars). The large SSKs, like the Soryu and future Shortfin, would rate highly. Small SSKs (eg. TKMS Ula class and Type 210mod) not so much.

SORYU TABLE (with earlier Oyashios) as at August 26, 2016

SS No.	Build No Name	Pennant No.	MoF approved amount ¥ Billions & FY	LABs, LIBs, AIP	Laid Down	Laun -ched	Commi-ssioned	Built By
5SS Oyashio	8105 Oyashio	SS-590/ TS3608	¥52.2B FY1993	LABs only	Jan 1994	Oct 1996	Mar 1998	KHI
6SS-15SS Oyashios 10 subs	8106 -8115 various	SS-591-600	¥52.2B per sub FY1994-FY2003	LABs only	Feb 1994		Mar 2008	MHI & KHI
16SS Soryu Mk 1	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	Mar 2013	2 Nov 2015	Mar? 2017	KHI
25SS	8124	SS-509	¥53.1B FY2013	LABs + AIP	22 Oct 2013	Nov? 2016	Mar? 2018	MHI
26SS	8125	SS-510	¥51.7B FY2014	LABs + AIP	2014	?	Mar 2019?	KHI
27SS First Soryu Mk 2	8126	SS-511	¥64.3B FY2015	LIBs only	2015	2017?	Mar 2020?	MHI
28SS  Second Soryu Mark 2	8127	SS-512	¥63.6B FY2016	LIBs only	2016?	2018?	Mar 2021?	KHI
29SS First of New Class	?	?	¥76B FY2018	LIBs only	?	?	2023?	MHI?

Table courtesy of information provided to Submarine Matters. LABs = lead-acid batteries,  AIP = air independent propulsion, LIBs = lithium-ion batteries. ¥***B = Billion Yen.

HIGHER COST FOR HIGHER PERFORMANCE OF SORYU MARK 2s (Mk 2s) 
THEY ARE 27SS AND 28SS

[Pete Comment - The budgeting for the Japanese Ministry of Defence (MoD) is single year and multi-year depending on the documents. The Board of Audit (BoA) and Ministry of Finance (MoF) need to be convinced that ongoing or higher funding is needed for MoD's new submarine requests. The conceptual complexity of these requests is something MoD needs to constantly explain to MoF and to other relevant branches of Government.] 

Gleaned from Comments The non-AIP Soryu Mark 2’s (27SS onwards) and follow-on class will paradoxically have some structural similarities to the non-AIP Oyashios that preceded the AIP Soryu Mark 1’s.

The Oyashios themselves are undergoing life extension, including combat system upgrades, to bring Japan’s operational submarine numbers up from the existing average of 16 up to 22 (to meet increasing strategic threats to Japan). (24/7/16 11:35 AM)

Gleaned from Comments (on 21/8/16 3:30 PM) In the FY 2018 budgetary request, the Japanese Ministry of Defence (MoD) will request 76 billion Yen (0.99 billion AUD) for the first of the New Submarine Class (29SS) which will be Commissioned? “End of FY 2021” [that is in 2022?]. 29SS will be equipped with an improved sonar system and will be more silent/stealthy.

Comments gleaned May 2016 to August 2016

New Snorkel Budgeting Details

[Pete comment - Japan is perfecting a new snorkel system that is effective in the higher sea states (eg, storms) that are common in the Pacific.]

(12/5/16 2:19 PM) The snorkel generation system which MoD will use for Soryu Mark 2s (27SS and 28SS) is to be consist of a snorkel system and diesel generator. This terminology is rather difficult to understand, because the snorkel system does not generate power. But, this odd terminology has important meaning in the MoD budget and tender system.

27SS budget complexities

A competitive tender is applied for purchasing the diesel generator, because it is general equipment. In contrast, an optional contract can be applied for purchasing the snorkel generation system, according to related law [known as Cabinet Order on Budgets, the Settlement of Accounts, and Accounting (Chapter VII), Article 102-4, (iii)]. The suppler of snorkel generation system can select diesel generator as part, and consequently MoD can effectively exclude undesired diesel generator, I think.

The MoD may explain the increased budgets for 27SS and 28SS to the Board of Audit (BoA), but BoA will not accept the increased budget [merely] due to the price of LIBs. If 27SS and 28SS are not equipped with the new snorkel generation system, the floating [elastc sound reducing] deck and new sonar system, the price of 29SS which utilises these systems and new [G-RX6 see above] torpedoes will be nearly 80 billion yen. This is too expensive. [Pete comment - This quite confusing logistical budgeting situation will be clarified over time.]

Higher LIBs performance at higher cost

The new propulsion systems for LIBs-Soryus (27SS and 28SS) are more expensive (1.1 billion yen) than those for LABs-Soryus (0.9 billion yen). TMEIC (Toshiba Mitsubishi-Electric Industrial Systems Corporation) won the competitive tender of the propulsion systems against the conventional supplier, Fuji Electric Co., LTD.

It is expected the new propulsion systems are much more powerful than those for LABs-Soryus. LIB Soryus 27SS and 28SS will have a higher maximum speed than previous Soryus (reliant on LABs).

This is assuming

i)    increases in numbers and energy density of battery modules are both +50%,

ii)   maximum speed of submarine is proportionate to cube root of total capacity of batteries,

iii)  hotel loads at maximum speed are same for LIBs and LABs Soryus.

G-RX6 - Future Heavy Weight Torpedo

It is not clear whether the FY 2018 budget for the first of the New (post Soryu) Submarine Class 29SS includes the new torpedo, G-RX6, cost or not. If the cost of the G-RX6s is not taken into account for this budget request, this will present a budgetary problem. The 29SS, if equipped with G-RX6s, will too expensive (eg. 80 billion Yen). 


Judging from the budget status for development of the G-RX6, the development has nearly finished and 29SS can be equipped with G-RX6s. It is expected the 29SS will show much superior performance to current AIP Soryu Mark 1s (16SS to 26SS), because 29SS is 50% more expensive than 26SS!

-  See http://www.mod.go.jp/trdi/en/research/gijutu_senpa_en.html Japan is developing the Heavy weight [G-RX6] torpedo (HWT) for submarine, in order to oppose highly efficient surface warships and submarines. The HWT hass an advanced [Torpedo counter counter measures] TCCM function, and is excellent in detection, tailing, and the performance in deep and shallow ocean. The TCCM capability reduces or eliminates the effect of enemy ship's or submarine's decoys and acoustic jamming. [Pete comment: It is strongly assumed Japanese HWTs share technology with the US Mark 48 eg. in TCCM and  deeper/shallower performance.]

Pete and Japanese Friends