April 26, 2017

Figure 5 Relationship between output of DE and IR for a LIB-submarine on patrol.

Anonymous has kindly provided the following figure and description. This is in the context of Anonymous's previous article Submarine electricity discharge & generation using combinations of Diesels, LIBs, LABs & AIP of April 20, 2017.

Figure 5 Relationship between output of a Diesel generator (DE) and Indiscretion Ratio (IR) during a LIB submarine’s patrol.
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The Vertical axis (above) is output of the is in kW.

The Horizontal axis is Indiscretion Ratio (IR) expressed as:

time for snorting /time for snorking + time for operating AIP or batteries) x 100

Power required (PT) is: Propulsion Load (PL= 60kW) and Hotel Load (HL)

Blue, PT=250kW (HL=190kW) based on current submarine; red, PT=300kW(HL=240kW); green, PT=350kW (HL=290kW); violet, PL=400kW(HL=350kW). IR=indiscretion ratio.

With the combat system requiring large amounts of electricity, Lead-acid Batteries (LABs) frequently cannot satisfy the electrical requirement because of its poor capacity. As a result, the capability of  the sonar system of a LAB submarine is inferior to that of an SSN.

In contrast, Lithium-ion Batteries (LIBs) can meet the high electical requirements. Utilising higher kW DEs, LIBs can supply more electricity for the HL, remembering that the PL also requires large amounts of electricity in a large conventional submarine.

If the output of DE is 6000kW within the framework of snorting ability, there is an excellent Indiscretion Ration of 6.25% where expected PL  is 400kW and HL is 350kW..

A well-developed LIB-submarine has the following advantages:
i)        a reduction in indiscretion ratio,
ii)      improvement of high speed performance, and
iii)    enhancement of sensors and processing systems.

Anonymous

April 25, 2017

Submarine Matter's expectation of an Ohio class SSGN now confirmed

On April 13, 2017 Submarine Matters published an article, US & Japanese ABM - BMD forces slowly approaching North Korea, which stated:


"Submarine-wise one SSN or two (with Tomahawk land attack missiles) would normally accompany the Carl Vinson Group. To enhance the option of a first or second strike of Tomahawk SLCMs onto NK targets a US Ohio SSGN might also be on hand in the region. Submarine fired Tomahawks all have the advantage of a greater element of surprise because they can emerge from unexpected undersea launch points."
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This suspicion was confirmed 11 days later on April 24-25, 2017 when Fox News reported

"The USS Michigan, a nuclear powered Ohio class submarine will pull into the South Korean port of Busan for a hull check in the coming hours, military sources confirmed Monday to Fox News...The USS Michigan is one of four Ohio-class guided-missile submarines, originally designed to launch nuclear missiles, that were converted between 2003 and 2007 to be able to fire Tomahawk cruise missiles....The USS Florida (SSGN 728) was converted in August 2003, the USS Michigan (SSGN 727) in October 2004, the USS Ohio (SSGN 726) in December 2005, and the USS Georgia (SSGN 729) in December 2007."


A US Ohio class SSGN is very large (around 17,000 tons (surfaced) and 19,000 tons (submerged)). Its size can be judged from how small the crew look standing on the hull.
Can astute readers spot the (non-Asia Pacific) location?
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Pete

April 24, 2017

Japan & US - No submarine building Unions? But the Most Efficient?

I’ve been doing a bit of research on  Japanese and US submarine building industries.

Japan has built submarines almost uninterrupted since 1906. That interruption occurring 1945-1957 when Japan was devastated by bombs and a US submarine blockade.

Japan has two large submarine building companies:
-  the conglomerate Mitsubishi Heavy Industries (MHI) (see a MHI built submarine), and

-  Kawasaki Shipbuilding Corporation (KSC) of the KHI conglomerate, See a Kawasaki submarine website.

They form a submarine building duopoly in the port city of Kobe, with each company continuous building one submarine every two years with launches occurring alternatly and rigidly every October to December. For the on-time, on-budget, schedule see the SORYU-Oyashio TABLE.

The structure of Japanese shipbuilding unions is quite complex, starting with likely extinct Japanese shipbuilding union "Zenzosen". Ztev Konrad advises (comments 25/4/17 8:12 AM below) from Wikipedia "Zenzōsen [the All Japan Shipbuilding and Engineering Union] is a federation of individual, enterprise-level unions - the normal model of trades unionism in Japan. It was initially the dominant union in the Japanese shipbuilding industry, but was [dissolved on September 9, 2016] eventually eclipsed by the Jūki Rōren (Japanese Federation of Shipbuilding and Engineering Workers' Unions). Zenzōsen was the more militant of the two unions, and was more strongly represented at the smaller shipyards. Zenzōsen was affiliated to the Japanese Socialist Party." https://en.wikipedia.org/wiki/Zenz%C5%8Dsen "Pete was on the right track with likely company unions dominating the sub shipyards."

In that direction S advises (comments 25/4/17 9:24 PM) that there are two worker’s unions (KHI Worker’s Union, Federation of Worker’s Union of the KHI Group of companies). The KHI Worker’s Union consists of 9 branches. Workers of KHI Kobe Shipyard belong to KHI Kobe branch.
S continues that information on MHI workers’s unions is not clear. Workers of MHI's Kobe Shipyard belong to the MHI Kobe Shipbuilding Branch.
The workers’s unions of KHI and MHI both belong to the Japanese Federation of Basic Industry Worker’s Union (JBU). JBU is an industrial union confederation of 400 worker’s unions with 251,965 members (source is Japanese wikipedia)."

I am guessing the submarine building workforces of MHI and KSC are around 1,000 each (2,000 total). Perhaps the Japanese Ministry of Defense and ATLA (a sub example) have 1,000 staff total dedicated to submarine research, contracts, production and availability?
Along with the US Japan might be the most efficient submarine builder in the world. This comes from:
1.  duopoly conditions (a government can always favour the competing company)
2.  continuous build (Japan building one SSK every year and the US building 1 to 2 SSNs)
3.  long runs of submarines with relatively few changes eg. few differences between the 10 Soryu
     Mk. 1s (see TABLE) and between the first 39! Los Angeles SSNs, and
4,  only building subs for one customer (US or Japanese) in their own navies.

Or perhaps other counties are more efficient by other measures such as:
-  country A achieving greater economies of scale, through production for foreigners, than A's 
   domestic demand can provide, or
-  raising foreign exchange through sales to foreign customers.

It takes the large, wealthy US economy to build an SSN or two each year (and eventually one Columbia class SSBN as well). The USSR used to churn out nuclear submarines at that rate but this was a major contributor to the ruination of its economy. China still cannot afford it or is dissatisfied with its SSNs' quality, prefering to mass produce SSKs instead.

A Japanese Soryu submarine being launched, with much fanfare, in Kobe.

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A Virginia class SSN under construction at Huntington Ingalls Industries Inc - Newport News. Note the propulsor about a mile back, in the distance :)
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Pete

April 20, 2017

Submarine electricity discharge & generation using combinations of Diesels, LIBs, LABs & AIP

Following last week's articles (here, here and here) Anonymous continues representation of electricity discharge and generation using combinations of Lithium-ion Batteries (LIBs), Lead-acid Batteries (LABs) and Air Independent Propulsion (AIP). An extra variable is use of Diesels on full or half power.

Tables 1 and 2 present extra comparative information.


Figure 4 (below) is the output of diesel generators for model submarines:

Diesels in LIBs-sub operate once every two-days (no operation on Day 2) using diesel on full power.
(a) LIBs + new diesel generator (GE), Power of new Diesel increases to 125% compare to old Diesel. This is noting LIBs require (or benefit from) more powerful Diesels.
(b) LIBs + full power Diesel, 

C-rate of LABs is 0.2C. Output of each Diesel is 2 and 4M in half and full power, respectively.
(c) LABs + half power Diesel + AIP. In AIP operation. LABs are not discharged.
(d) LABs + half power Diesel, Operation cycle of LABs-sub is once a day. 

Grey represents no generation using Diesel; 
Green represents Diesel generation; 
Purple represents AIP generation; 

Lower axis Figure 4 represents electricity discharge and generation according to which team of the 3-watch crew roster are on duty. Where:
- Red represents team 1;
- Yellow represents team 2; 

- Blue represents team 3;  

Figure 4 
8

















































6
















































4


Snorkeling/Diesel

(a)  LIBs+new Diesel (day 1 of 2 days)

















2
Discharge





Discharge to day 3, 20:00






0

















































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4








(b) LIBs +full power Diesel (day 1 of 2 days)







Snorkeling/Diesel







2
Discharge
Discharge to day 3, 20:00







0

















































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6

















































4








(c) LABs + half power Diesel + AIP (every day)





























2
Discharge
Snorkeling/Diesel

Discharge

AIP mode (240kW)

0

















































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4








(d)LABs + half power Diesel (every day)































2
Discharge
Snorkeling/Diesel
Discharge
Snorkeling
/Diesel
Discharge

0
























MW
























time
19

20

21

22

23

00

01

02

03

04

05

06



Table 1 - Performances of models
Model
Indiscretion ratio, IR [1] %
Submerge at max speed [2] h
Capacity of battery
MW
Output of Diesel [3]
MW
Rotation of Diesel
rpm
C-rate
Current
status
Limit [4]
LIBs + new Diesel
5.2
10
50
5
1200
0.1
1
LIBs + full power Diesel
6.3
10
50
4
1200
0.08
1
LABs + half power Diesel AIP
8.3
1
10
2
600
0.2
0.4
LABs + half power Diesel
12.5
1
10
2
600
0.2
0.4
[1] LIBs, IR=operation time (green)/48 x 100; LABs, IR= green/24 x100.
[2] Max speed is 18 knots; Energy consumptions are 4.5 and 40.5MW for LABs and LIBs, 
respectively.
[3] Data is total output of 2 Diesels. Model sub is equipped with 2 Diesels operating 
simultaneously.
[4] C-rate of LIBs is general data. Value of LABs is for high speed charge/discharge rate.


“C” means one Coulomb. C-rate is the inverse of charging time in hours. An empty
  battery with a C-rate of 0.5 just needs 2 hours to be recharged completely.


Table 2 -  Important factors
Term
Discussion
LAB
LIB
C-rate
As C-rate of LAB is small (0.1C, 0.2C) and capacity is low, C-rate dominates charge/discharge rate. Higher C-rate (0.4, 0.5C) is possible, but, it shortens life of LAB. Half power of Diesel can satisfy C-rate of 0.2C.
Dominative
-
Output of Diesel
As C-rate of LIB is large (0.5C, 1C) and capacity is high, output of Diesel  dominates charge/discharge rate. To get low indiscretion ratio, output of Diesel needs to be increased. In Fig.4 (a), C-rate is only 0.1C. Higher rotation of Diesel or increase of Diesels is possible measure, but it increases noise or vibration.
-
Dominative
Snorkel capacity
To realize high performance of LIBs, an improvement of the Diesel will be conducted within framework of snorkel system capacity to effectively discharge exhaust gases.

To achieve C-rate of 1 for LIBs is difficult (max. two- or three-fold increases?), C-rate of 1 is difficult to achieve (max 02-0.3?).
-
Dominative
Propulsion motor
To achieve high speed performance by LIBs, improvement of propulsion motor is required.
-
Important
Conclusion
To realize high performance submarine equipped with LIBs, comprehensive improvement of power system including Diesel, snorkel system and propulsion motors as well as development of LIBs are required.
Also, improvement and establishment of peripheral technologies including safety system and further reduction of noise/vibration are needed.

Anonymous