The latest installment in the eternal USN SSN vs. SSK debate

[Lex Parsimoniae]

An interesting article from a well-known Naval War College professor:

http://www.usni.org/magazines/proceedings/story.asp?STORY_ID=2382

 

[Pat in Halifax]

Interesting article which truly makes one think. I wonder if our "decision makers" might jump on this saying they knew it already to justify draining both FMFs of resources the last 6-8 years.  I recall during my last 'shore posting' (49 days!) at FMF CS as a TSS. I would get a cell phone call at home around 0600 from someone else saying that somebody senior had woke up dreaming "black" which meant, reel in all your crews and stand by to stand by (and call the PM desk-Submarines on the 3rd floor!)
All pessimism aside, this may be the ticket to Canada formulating a policy on submarine employment. I just finished up the conference in Halifax and that was an area largely ignored I believe because no one really had an idea. There was a talk early on (on day 1 I think) about some of the ASW and 'shadowing' patrols in the 80s and 90s (recently declassified) and drug interdictions in the 90s but no mention of future employment of this unique platform. Too bad I didn't see this article last week.

 

[Retired AF Guy]

" FMF CS as a TSS."??? Sorry I'm not familiar with navy lingo.

 

[Neill McKay]

" FMF CS as a TSS."??? Sorry I'm not familiar with navy lingo.

Fleet Maintenance Facility Cape Scott (in Halifax), but TSS is a new one on me too.

 

[Pat in Halifax]

Technical Support Supervisor (Sorry!!!); Generally for subsystems there is one civilian and one military working together. These are the individuals who take the work requests from the planners and with the assigned priority, assign specific crews to jobs. They work alongside each ship's PL (Project Leader) to get everything done (yeah right!!) the ship has asked for during a Work Period. It is actually quite interesting but sometimes can be self defeating. If a Task Group is out for example and no one is dreaming about submarines that week then there is likely only one 'Normal Readiness' unit alongside - any work should be a no brainer. I actually got into a bit of ka-ka for coming in one morning and sending a couple guys (uniformed) down to one of the ships with no paperwork.
Anyway, back on the topic, this sounds like a bit of leverage for a 'cheaper' submarine force (Cheaper meaning conventionally powered vice nuclear-not related to quality)

 

[drunknsubmrnr]

The article's writer is handwaving away the difficulty and expense in supporting SSK operations, while overemphasizing the utility of operating in very shallow waters.

Tenders are extremely expensive to build and run. They require most of the manpower and capabilities of an FMF, while keeping everything in a basic hull. That hull is also very vulnerable. Losing it will cripple a Navy's SSK capabilities to the point the money would have been better spent elsewhere.

SSN's are able to run just fine in shallow water, and not many submariners of any type will willingly go into water quite as shallow as he mentioned. SSN's are also able to sit on the bottom, using the same techniques as SSK's.

He's also mixing costs. An SSK built to USN standards wouldn't be much cheaper than an SSN, since almost all of the really expensive equipment would be the same between the two types. Same combat system, same sensors, same weapons, same diesels. That leads to pretty similar costs for a lot less capability.

 

[Lex Parsimoniae]

Tenders are extremely expensive to build and run. They require most of the manpower and capabilities of an FMF, while keeping everything in a basic hull. That hull is also very vulnerable. Losing it will cripple a Navy's SSK capabilities to the point the money would have been better spent elsewhere.

Why do you believe that an SSK requires a tender to deploy with it?  Name a single western nation that deploys tenders with their SSK?  SUBPAC had a number of forward deployed diesel boats [USS Barbel (SS-580), USS Blueback (SS-581), USS Bonefish (SS-582), and others] in WesPac without tender support, or need for tender support, for most of the cold war, including a number of black ops during the Vietnam War.  Voyage repairs and overhauls were conducted in Yokosuka and Subic Bay.

SSN's are also able to sit on the bottom, using the same techniques as SSK's.

How do you deal with the reactor cooling inlets?

He's also mixing costs. An SSK built to USN standards wouldn't be much cheaper than an SSN, since almost all of the really expensive equipment would be the same between the two types. Same combat system, same sensors, same weapons, same diesels. That leads to pretty similar costs for a lot less capability.

Many submarine forces have QA programs that are equivalent to SUBSAFE.  The major portion of the budget for an SSN is the reactor (never mind the TBD disposal costs).  Look at what a T-Boat cost vs. an Upholder.  Essentially the same hull, auxiliary systems, sensors, but substantially more expensive.

 

[drunknsubmrnr]

Why do you believe that an SSK requires a tender to deploy with it?  Name a single western nation that deploys tenders with their SSK?

Math mostly. Boats normally operate <1000 miles (aka ~1 weeks transit) from their base/tender. If you happen to have a properly equipped base within 1000 miles of all probabable targets you probably don't need a tender but I think you'll find that isn't the case for even the US. Thats one reason that most countries don't deploy SSK's abroad any more.

SUBPAC had a number of forward deployed diesel boats [USS Barbel (SS-580), USS Blueback (SS-581), USS Bonefish (SS-582), and others] in WesPac without tender support, or need for tender support, for most of the cold war, including a number of black ops during the Vietnam War.  Voyage repairs and overhauls were conducted in Yokosuka and Subic Bay.

I think if you look at a chart you'll find that the operating areas for those SSK's were ~1000 nm from either Subic Bay or Yokusuka, which were both full fleet bases boasting more facilities than we could provide in Halifax. Note that smaller harbours such as Apra and Holy Loch had tenders.

SSK's replaced SSN's when the SSN's weren't available, not because they were the best platform. They were banned from inshore ISR vs the Soviets before the Vietnam War really got started...one was found and hunted pretty much to exhaustion by the Soviet Navy.

How do you deal with the reactor cooling inlets?

Same way you keep muck out of your tank inlets and the screw clear: trim forward when you're just above the bottom. The bow sits on the bottom, and the screws and inlets stay a few feet off the bottom.

Look at what a T-Boat cost vs. an Upholder.  Essentially the same hull, auxiliary systems, sensors, but substantially more expensive.

Costs in the mid-80's for a Trafalgar were ~275 million $US while the Upholders were advertised at 215 million $US. Thats not that much more expensive, although operating costs would be a lot higher for an SSN.

 

[Lex Parsimoniae]

Math mostly. Boats normally operate <1000 miles (aka ~1 weeks transit) from their base/tender. If you happen to have a properly equipped base within 1000 miles of all probabable targets you probably don't need a tender but I think you'll find that isn't the case for even the US.

Where does the 1000 mile limit come from?

Same way you keep muck out of your tank inlets and the screw clear: trim forward when you're just above the bottom. The bow sits on the bottom, and the screws and inlets stay a few feet off the bottom.

Even if an SSN skipper was willing to get his inlets that close to the muck on the bottom, how do you avoid damaging the bow array?

 

[Sub Standard]

Even if an SSN skipper was willing to get his inlets that close to the muck on the bottom, how do you avoid damaging the bow array?

Most boats have their bow array on the top half of the forward dome and the torpedo tubes on the bottom.  This includes the USN SSNs.  The Victoria class is one of the only ones to be reversed.

 

[drunknsubmrnr]

Where does the 1000 mile limit come from?

It's about 1 week's transit. Leaves about 30 days on patrol out of a nominal 45 days endurance.

Even if an SSN skipper was willing to get his inlets that close to the muck on the bottom, how do you avoid damaging the bow array?

The bow array is inside a free-flooding fiberglass shroud, as well as being placed away from the bottom. It's in more danger from a collision than a grounding.

 

[Lex Parsimoniae]

Most boats have their bow array on the top half of the forward dome and the torpedo tubes on the bottom.  This includes the USN SSNs.  The Victoria class is one of the only ones to be reversed.

Not a bad guess.  Older SSNs did indeed have their sonar arrays on the top but many/most navies went away from that approach with the advent of wire guided weapons. 

Here are some open source drawings of modern submarines with the sonar array on the bottom/front:

688 (the largest class of SSN ever produced):
http://commons.wikimedia.org/wiki/File:Los_Angeles_class_submarine_3D_drawing.svg

Astute Class:
http://www.naval-technology.com/projects/astute/astute11.html

Barracuda Class:

http://www.naval-technology.com/projects/barracuda/barracuda2.html

Oscar II Class:
http://www.naval-technology.com/projects/oscar/oscar6.html 

Kilo Class:
http://www.naval-technology.com/projects/kilo/kilo9.html

 

[Lex Parsimoniae]

It's about 1 week's transit. Leaves about 30 days on patrol out of a nominal 45 days endurance.

I’ll try re-phrasing my question.  Why do SSKs need a tender but SSNs don’t?

The bow array is inside a free-flooding fiberglass shroud, as well as being placed away from the bottom. It's in more danger from a collision than a grounding.

Without explaining the technical reasons for why the fibreglass needs to be protected, look at pictures from the groundings of USS San Francisco, HMS Trafalgar, and HMS Superb…

 

[drunknsubmrnr]

Older SSNs did indeed have their sonar arrays on the top but many/most navies went away from that approach with the advent of wire guided weapons.

If you look at the non-USN SSN's, you'll see that that the arrays wrap around the front and both sides. They don't carry directly under the bow where they'd touch down.

Why do SSKs need a tender but SSNs don’t?

SSN's can transit roughly 6000 nm in a week, rather than an SSK's 1000 miles. That means they can use a base that's a lot farther away. SSN's also have longer endurance, allowing worldwide deployments from just a few bases.

Without explaining the technical reasons for why the fibreglass needs to be protected, look at pictures from the groundings of USS San Francisco, HMS Trafalgar, and HMS Superb…

There's a big difference between a light touchdown at very slow speed, and smacking into a seamount at 30 knots.

 

[Lex Parsimoniae]

If you look at the non-USN SSN's, you'll see that that the arrays wrap around the front and both sides. They don't carry directly under the bow where they'd touch down.

Which leaves them vulnerable to your proposed touch down and trim forward technique.  The lack of a keel block is another impediment to bottoming since the base of the sonar array doesn’t appear to be sufficiently reinforced to support that kind of weight.  However this discussion is about USN SSNs and they clearly cannot bottom due to their spherical arrays.  Take it from an anonymous internet source – SSNs cannot bottom due the reactor cooling pumps regardless of bow sonars.

SSN's can transit roughly 6000 nm in a week, rather than an SSK's 1000 miles. That means they can use a base that's a lot farther away. SSN's also have longer endurance, allowing worldwide deployments from just a few bases.

Using assumed speeds of <6 kts for an SSK and >35 kts for an SSN???

There's a big difference between a light touchdown at very slow speed, and smacking into a seamount at 30 knots.

True enough but that wasn’t the case for the two British boats.

 

[drunknsubmrnr]

Which leaves them vulnerable to your proposed touch down and trim forward technique.  The lack of a keel block is another impediment to bottoming since the base of the sonar array doesn’t appear to be sufficiently reinforced to support that kind of weight.

They only have a very slight load when touching down. Lack of a keel block is irrelevant, since they're under water all the time and only very slightly negatively bouyant.

However this discussion is about USN SSNs and they clearly cannot bottom due to their spherical arrays.  Take it from an anonymous internet source – SSNs cannot bottom due the reactor cooling pumps regardless of bow sonars.

Cough...Ivy Bells...cough.

Using assumed speeds of <6 kts for an SSK and >35 kts for an SSN???

About that, yes.

True enough but that wasn’t the case for the two British boats.

Close enough. Trafalgar's BoI had her grounding at 14.7 knots at a constant depth. There's a huge difference between that and tapping the bottom at 0 knots.

 

[Lex Parsimoniae]

Cough...Ivy Bells...cough.

from Wikipedia...

... August 1968 when she transferred to Mare Island for overhaul and installation of: side thrusters; hangar section sea lock; anchoring winches with fore and aft mushroom anchors...

Since it is not really relevant to the debate of SSK vs. SSN, I'll move on from your insistence that SSN can bottom despite Dr Vego publishing in a USN journal that "...an SSN cannot sit on the bottom because of the danger of clogging vital inlets to condensers..." 

The thrust of Dr Vego's pro-SSK argument doesn't rely on their ability to bottom but instead centres around cost, size, and their ability to perform some missions in the littorals more effectively than SSNs.

 

[a_majoor]

This debate may become moot as technologies advance. Very small reactors which use thorium salts now exist which provide electrical energy without the need for large, highly trained staffs for day to day operation (the ultimate example of this design is being sold as a nuclear battery, just bury it and let run for a decade or more), potentially allowing for very small boats with the size of an SSK but the power density of an SSN (The engine room would be far smaller than that of an SSN or even SSK). Even without the exotic form of nuclear reactor, the USN had instituted a program called Bravo Tango which was forecast to create capable SSN's with about half the displacement of current attack boats, so the ability to operate in shallow waters would be greatly enhanced.

Fuel cell technology is advancing and other AIP technologies will give notional SSK's the abilities of SSN's for periods of time, further blurring the line between the two. Submarines may end up being classified as "Littoral" and "Blue Water" based on their ability to cruise at speed or shallow water performance rather than their propulsion systems. As for which ones the USN will buy, a combination of service requirements and politics will decide at the end of the day.

 

[drunknsubmrnr]

.. August 1968 when she transferred to Mare Island for overhaul and installation of: side thrusters; hangar section sea lock; anchoring winches with fore and aft mushroom anchors...

She needed anchors because she routinely stayed on the bottom for extended periods, and the operations she conducted needed an extremely stable platform.

Since it is not really relevant to the debate of SSK vs. SSN, I'll move on from your insistence that SSN can bottom despite Dr Vego publishing in a USN journal that "...an SSN cannot sit on the bottom because of the danger of clogging vital inlets to condensers..." 

Dr Vego's article was in Proceedings, which is published by the US Naval Institute and is not part of the USN. FWIW, that article was thoroughly fisked in submariner circles when it came out.

The thrust of Dr Vego's pro-SSK argument doesn't rely on their ability to bottom but instead centres around cost, size, and their ability to perform some missions in the littorals more effectively than SSNs.

A lot of the reasons he gave to back up his opinions were factually wrong, leading to incorrect conclusions.

 

[Lex Parsimoniae]

She needed anchors because she routinely stayed on the bottom for extended periods, and the operations she conducted needed an extremely stable platform.

Bottomed and anchored? ;D 
FYI - it's the weight of the anchor cable that holds a vessel fast and not the anchor itself.  How do you run the cable out while bottomed or vice versa?

Dr Vego's article was in Proceedings, which is published by the US Naval Institute and is not part of the USN. FWIW, that article was thoroughly fisked in submariner circles when it came out..

USNI is as close to an inside journal as possible but whatever.  Dr. Vego is a professor of operations at the Naval War College. Before coming to the United States in 1976, he served as commanding officer of torpedo boats and gunboats in the former Yugoslav Navy and as 2nd officer (Deck) in the former West German merchant marine. He is the author of Naval Strategy and Operations in Narrow Seas (London: Frank Cass Publishers, 1999 and 2nd ed., 2003), and of many articles on littoral warfare.  I'll take his word over some bloggers who let their obvious nuclear bias overrule any possible discussion of non-nuclear for the USN.

A lot of the reasons he gave to back up his opinions were factually wrong, leading to incorrect conclusions.

Such as?