The Ship Model Forum

Yes, the air emitter was on both sides of the sail. See attached photos of the late, great Clamagore with Masker piping indicated at red arrows.

Prairie-Masker was an addition to the Guppy subs and was not on the original versions. I don't know if the step sail versions (Electric Boat and Portsmouth sails) ever received the Master system. The Guppy III "Atlantic" plastic sail presented a large, slab like aspect to sonar and did receive the Masker piping.

Really good point about the surface area of the sail, hadn't thought about that.

Was the emitter pipe on both sides of the sail?

Additionally, I'm not seeing this on EB or Portsmouth GUPPY sails? Anyone know the history?

[quote="CC Clarke"]The Prairie Masker system's purpose was two-fold, taking advantage of sound transmission trying to pass through two very different mediums (air being 1/4 the density of water: Approx 1100 fps compared to 4800 fps.) The Masker attenuated own-ship's noise and degraded active sonar returns.

Prairie refers to the air released to reduce cavitation. Masker was the "bubble curtain" which enveloped the hull.

The sail is a huge flat surface whose sides reflects active sonar. Sound doesn't transmit through water to air to water efficiently as it tries to pass through bubbles. Some surface ship classes have employed versions of the system.

Anechoic tiles were the next evolution in external sound silencing and active sonar attenuation, in addition to acoustic countermeasures, which are launched when you've been snapped-up (detected); -another topic altogether.[/quote]

The Prairie Masker system's purpose was two-fold, taking advantage of sound transmission trying to pass through two very different mediums (air being 1/4 the density of water: Approx 1100 fps compared to 4800 fps.) The Masker attenuated own-ship's noise and degraded active sonar returns.

Prairie refers to the air released to reduce cavitation. Masker was the "bubble curtain" which enveloped the hull.

The sail is a huge flat surface whose sides reflects active sonar. Sound doesn't transmit through water to air to water efficiently as it tries to pass through bubbles. Some surface ship classes have employed versions of the system.

Anechoic tiles were the next evolution in external sound silencing and active sonar attenuation, in addition to acoustic countermeasures, which are launched when you've been snapped-up (detected); -another topic altogether.

Question about the use of the Prairie/Masker system used on GUPPYs. Looking at the elevation drawings of a number of GUPPYs I've noticed the masker system called out on the hull, but also on the the sail. Looking at pictures of the USS Razorback, Clamagore, etc you can see the masker line running down the side of the sail that is also called out on the drawing. I can understand the use of the masker on the side of the hull to quiet mechanical noise while snorkeling, but I'm more interested in the masker use on the sail. Was the sail considered a source of mechanical noise leak? I've only vetted the Atlantic sail contingent, but was the sail Masker also used on EB and Portsmouth sailed GUPPYs?

Excellent find, thanks for posting!

Jacob

Thought this would be of interest to some here, details of the passive sonar on the USS Cochino (some interesting images showing the streamlined sonar plus drawings as well as operating details). I hadn't seen this before, maybe it's also new to others:

[url]https://www.mulsannescorner.com/models/Submarines/USS%20Cochino/AD1135105.pdf[/url]

[quote="Tom Dougherty"]My resin 1/350 version of a Guppy submarine is in the “ What’s New” section. Unfortunately, the ModelWarships main page has not been updated to reflect the posting of my model as well as two additional models.

Tom[/quote]

Here is Tom's Becuna:

http://www.modelshipgallery.com/gallery/ss/ss-319/Becuna-350-td/index.htm

My resin 1/350 version of a Guppy submarine is in the “ What’s New” section. Unfortunately, the ModelWarships main page has not been updated to reflect the posting of my model as well as two additional models.

Tom

I'm not sure exactly when it was first at sea, but the idea appears to date from the 1920s, although the application was to provide an acoustic baffle for a destroyer sonar. The use of bubble curtains for quieting came right after WWII. I would guess that the GUPPYs got it around 1960, plus or minus five years maybe.

As for the Russians, I recall seeing a few things on some of their diesel boats that look like girth emitters, but I wasn't able to find much (I don't know what such a system is called in Russian).

I found an interesting paper on the subject (which you can access via sci-hub): https://doi.org/10.1190/1.1441340

[quote="Vepr157"][quote="Woodstock74"]Interesting, so the only possible visual indication of Prairie/Masker are what are effectively pipes I'm guessing running outside the pressure hull/exterior cladding?[/quote]

Right. The hull emitters are often difficult to spot, but the stern ones are very apparent. Although it's not a fleet boat, this photo shows the aft piping on the Tang (the pipes look pretty much the same on GUPPYs):

[img]https://i.imgur.com/rxyFZfh.jpg[/img][/quote]

When did this system originally debut? Did the Soviets ever come up with something similar?

[quote="Woodstock74"]Interesting, so the only possible visual indication of Prairie/Masker are what are effectively pipes I'm guessing running outside the pressure hull/exterior cladding?[/quote]

Right. The hull emitters are often difficult to spot, but the stern ones are very apparent. Although it's not a fleet boat, this photo shows the aft piping on the Tang (the pipes look pretty much the same on GUPPYs):

[img]https://i.imgur.com/rxyFZfh.jpg[/img]

Interesting, so the only possible visual indication of Prairie/Masker are what are effectively pipes I'm guessing running outside the pressure hull/exterior cladding?

[quote="Woodstock74"]Is this shot of the Tork's screw indicative of Fleet Snorkel screws? As this image is of her in dry dock in modern day, wanted to make sure what I'm seeing would be accurate to in-era. I'm specifically wondering about the slots in the screw boss trailing edge. Is this part of the Prairie system?

[img]http://www.mulsannescorner.com/models/Submarines/Screws/Fleet%20Snorkel/DSC_2510.jpg[/img][/quote]

That looks like the standard fleet boat propeller, which is what I assume the fleet snorkels kept. I don't believe any of them get Prarie-Masker as it required an engine to be removed. The holes in the propeller blades are tiny, so the best way to tell is if there is a girth emitter and pipe leading to the propellers like this, which the Torsk doesn't have:

[img]https://i.imgur.com/3Cs118K.png[/img]

Is this shot of the Tork's screw indicative of Fleet Snorkel screws? As this image is of her in dry dock in modern day, wanted to make sure what I'm seeing would be accurate to in-era. I'm specifically wondering about the slots in the screw boss trailing edge. Is this part of the Prairie system?

[img]http://www.mulsannescorner.com/models/Submarines/Screws/Fleet%20Snorkel/DSC_2510.jpg[/img]

[quote="Tom Dougherty"]Here’s hoping she stays just down the road. The plan by Patriot’s Point was to sink her for an artificial reef for divers. The exterior hull is in bad shape, but the interior is in excellent condition. It is the sole remaining Guppy III.

Yeah, the printed description of the 1963 edition is sparse, to say the least. If it is not a reprint, but an update, I would expect it covers Guppy III.

I do know that the Guppy III program was an early 1960’s effort. The motivation to modify existing Guppy subs to Guppy III standard was due to the slow build up of nuclear SSNs. This was partly due to the diversion of building to the Polaris SSBN program, and later the delays due to the loss of Thresher and implementation of SubSafe measures.[/quote]

Someone posted images of the Clamagore taken recently and it appeared they were in the process of dismantling the upper deck structure, thus moving forward with the reefing plan? Man I hope not. Only one of her kind as you point out. That alone should be enough to spare her, surely? That and money, of course...

Here’s hoping she stays just down the road. The plan by Patriot’s Point was to sink her for an artificial reef for divers. The exterior hull is in bad shape, but the interior is in excellent condition. It is the sole remaining Guppy III.

Yeah, the printed description of the 1963 edition is sparse, to say the least. If it is not a reprint, but an update, I would expect it covers Guppy III.

I do know that the Guppy III program was an early 1960’s effort. The motivation to modify existing Guppy subs to Guppy III standard was due to the slow build up of nuclear SSNs. This was partly due to the diversion of building to the Polaris SSBN program, and later the delays due to the loss of Thresher and implementation of SubSafe measures.

[quote="Tom Dougherty"]There are two versions of the Guppy submarine book. The 1956 edition book is an update of the WWII Fleet Submarine Manual, hence a highly technical, nuts & bolts coverage of submarine systems. It uses Becuna, SS319 as the example. Becuna was a Guppy Ia, so features such as the expanded 514 cell battery of Guppy II are probably only mentioned. Since it was published in the 1950’s, coverage of the heavily modified Guppy III e.g., Clamagore) are absent. There is a later, 1963 Edition Submarine book also listed on the site below. That appears to cover the later and final evolution, the Guppy III. Again a highly technical coverage of the systems in these boats, The Guppy III boats were literally cut forward of the control room and a 15 foot “hull plug” installed to create space for an expanded sonar suite. Externally, they all had the High Atlantic Sail and three PUFFS sonar fins on deck. You can see more in my coverage of Clamagore here: [url]http://navsource.org/archives/08/pdf/0834331.pdf[/url]

Best source for the books (least expensive) is probably Periscope Films. Here are the manuals, including both of the Guppy manuals.
[url]https://periscopefilm.com/submarine-manual/[/url][/quote]


Came across your pdf the other night and grabbed it though until you pointed it out I wasn't aware you had written it! Very well done and it goes straight into my reference library. Love the Guppys and have been on the Clamagore before (about 11 years ago) as she's just down the road from me.

[quote="Tom Dougherty"]So that book is an update of the WWII Fleet Submarine Manual, hence a highly technical, nuts & bolts coverage of submarine systems. It uses Becuna, SS319 as the example. Becuna was a Guppy Ia, so features such as the expanded 514 cell battery of Guppy II are probably only mentioned. Since it was published in the 1950’s, coverage of the heavily modified Guppy III e.g., Clamagore) are absent. There is a 1963 Submarine book also listed on the site below. Whether that covers Guppy III, I don’t know.

Best source (least expensive) is probably Periscope Films. Here are the manuals, including the Guppy manual.
[url]https://periscopefilm.com/submarine-manual/[/url][/quote]

Thanks for the reply Tom. Reading through the description of the 1963 book it doesn't make any mention of Guppys so the Guppy-specific book (published in 1961) might be the way to go, though I'm now on the fence altogether, lol!

There are two versions of the Guppy submarine book. The 1956 edition book is an update of the WWII Fleet Submarine Manual, hence a highly technical, nuts & bolts coverage of submarine systems. It uses Becuna, SS319 as the example. Becuna was a Guppy Ia, so features such as the expanded 514 cell battery of Guppy II are probably only mentioned. Since it was published in the 1950’s, coverage of the heavily modified Guppy III e.g., Clamagore) are absent. There is a later, 1963 Edition Submarine book also listed on the site below. That appears to cover the later and final evolution, the Guppy III. Again a highly technical coverage of the systems in these boats, The Guppy III boats were literally cut forward of the control room and a 15 foot “hull plug” installed to create space for an expanded sonar suite. Externally, they all had the High Atlantic Sail and three PUFFS sonar fins on deck. You can see more in my coverage of Clamagore here: [url]http://navsource.org/archives/08/pdf/0834331.pdf[/url]

Best source for the books (least expensive) is probably Periscope Films. Here are the manuals, including both of the Guppy manuals.
[url]https://periscopefilm.com/submarine-manual/[/url]

Anyone have any thoughts about the book [u]The Submarine Guppy Edition[/u], [url]https://www.amazon.com/Submarine-Guppy-United-States-Navy/dp/1935327143[/url]?