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?
---

Pete

9 comments:

Anonymous said...

It is not an SSGN, but the Belgorod submarine will be even larger than a Typhoon, although based on an Oscar class design. It is supposed to carry Kanyon torpedoes as well as a deep diving midget submarine. Apparently Russia is building a nuclear powered sensor network 1km down on the sea floor in the Artic.
KQN

Josh said...

There are two PACFLT SSGNs with two crews a piece (they retain the Blue/Gold arrangement of the SSBNs). Given that the natural flash points in the Pacific for the US would be Chinese SCS islands and the DPRK, its reasonable to assume at any given time there's a good chance an SSGN is lurking just outside or just inside the first island chain even in times of relative calm. But making a port visit is underlining that presence to Xi and Fatty Kim.

Interestingly she's carrying a dry deck shelter for SEAL teams. This might imply that she had some other mission on this deployment or that she forward deploys like this to have the maximum number of options available (SEALS need not be on board for the whole deployment; they could be dropped off at a latter time). That would appear to cover up a half dozen of the available missile tubes however, reducing the BGM-109 strike she could put out.

Cheers,
Josh

Peter Coates said...

Thanks KQN

I'm sure one-off Belgorod will have a unique sound signature - something for US sensors to listen for then track.

Might Russian SLBMs and nuclear tipped SLCMs be greater threats?

It seems the US and USSR/Russia have tooled around with underwater static use small nuclear reactors or isotope batteries for decades. Projects have usually been discontinued as conventional batteries (or line array electrical connections) have become more efficient.
A known nuclear example is Ivy Bells https://en.wikipedia.org/wiki/Operation_Ivy_Bells#Use "Eventually, more taps were installed on Soviet lines in other parts of the world, with more advanced instruments built by AT&T's Bell Laboratories that were nuclear-powered and could store a year's worth of data.[2]:189"

Regards

Pete

Ztev Konrad said...

It seems that the conversion of the Trident tubes to vertical launch cruise missiles has led the USN to see its advantage and now new Virginia class submarines have similar diameter ( but not depth!) 'payload tubes in the forward hull ( outside the pressurized compartment)
http://foxtrotalpha.jalopnik.com/uss-john-warner-shows-off-jumbo-missile-tube-during-com-1722122511

"Virginia payload tubes’ large diameter and modular nature allows it to be adapted to larger diameter missiles in the future, breaking the previous 533mm diameter restrictions of the Tomahawk cruise missile. This will allow Virginia class submarines to more easily field emerging technologies, like hypersonic long-range missiles and it could even be used to launch and recover large autonomous unmanned underwater vehicles that can come and go for days, or even weeks at a time.

It seems that later Virginia production blocks will have more large diameter payload tubes further to the rear, but these seem to be full depth canisters , not just the length required for Tomahawk

Peter Coates said...

Hi Josh

The US SSBN/SSGN Naval Base Kitsap [1] in Washington State (US Pacific Coast) can cover the flashpoints in Northeast Asia you mention.

[1] Note that USS Michigan is listed as being main based at Kitsap
https://en.wikipedia.org/wiki/Naval_Base_Kitsap#Units.2C_warships_and_submarines

Forward bases for SSGNs may be:
- the US Seventh Fleet HQ Base at Yokosuka, Japan
- another south at Guam Naval Base, and
- even further south at Fremantle, Western Australia.

Yes. Every US SSGN I've seen on the Internet seems to have one dry deck shelter or two - so a semi-permanent fixture. I imagine China, N Korea would be too authoritarian-dangerous for a walk inland special forces mission.

Regards

Pete

Peter Coates said...

Hi Ztev

Yes it seems the US has been the leader in modern vertical launch tubes. Further back I think USSR/Russia (eg. Oscars and earlier SSGNs) had/have vertical and/or diagonal tubes. China seems to be developing vertical.

Germany for the Type 216 design contemplated large 6-7 cruise sized vertical and/or horizontal launch (and swim-out) known as Vertical multi-purpose locks (VMPLs). Sweden for the A26 design may incorporate a horizontal multi-purpose lock solution.

http://foxtrotalpha.jalopnik.com/uss-john-warner-shows-off-jumbo-missile-tube-during-com-1722122511 is interesting. There's a whole ongoing debate on the merits and downsides of SLBM capable Virginias (and maybe on later Astute SSGNs). Some similarity with nuclear tipped cruise-SLCM issues.

Regards

Pete

Josh said...

I believe Russian Echo/Charlie/Mike/Oscar platforms were diagonal. But all of those tubes were much larger affairs than the US ones (until the Ohio conversions). The newest classes of Russian and Chinese boats are to have VLS tubes, albeit more modest sizes than the payload tubes going into the most recent Virginias. While the new Virginia tubes are 'ballistic missile diameter', as far as I know they are not ballistic missile depth and couldn't be suited to that role. But if someone has a source saying they are I'd like to be informed.

I've actually never heard of SSGNs forward deploying. They have made port calls to friendly countries, but it is infrequent and definitely wouldn't qualify as a forward basing. They base with the regular SSBNs in Washington and Georgia as most of their maintenance needs are similar. In fact I'm not aware of the US ever basing nuclear subs in another country; I don't think even 7th Fleet in Japan actually hosts and maintains boats there.

Cheers,
Josh

Ztev Konrad said...

There was a relevant story about US submarine basing at Guam in a previous Submarine Matters
http://gentleseas.blogspot.co.nz/2015/06/guam-nuclear-submarine-and-air-base.html

It says the base supports SSGN,s Ohio and Michigan
Specialist facilities are provided by submarine tender USS Frank Cable

Peter Coates said...

Hi Ztev

Thanks for spotting that Submarine Matters in June 2015 at [ http://gentleseas.blogspot.co.nz/2015/06/guam-nuclear-submarine-and-air-base.html ]
already noted that Guam "Apra" Harbour naval base is used as forward base for SSGNs and mainly SUBRON 15 Los Angeles class SSNs.

As you say the (22,826 long tons full load) submarine tender https://en.wikipedia.org/wiki/USS_Frank_Cable_(AS-40) is a major facility in this forward base setup. The base is also served by long established shore facilities.

Regards

Pete