Calling all Thresher-class (SSN-593) & Permit-class (SSN-594) fans

[krgf15]

http://www.ebay.com/itm/USS-Thresher-SS ... 43d84048d7

Saw this on EBAY today, I have heard nothing about it until now. There is also a Permit. The hull is pre-colored, I'm not sure if I like that....

[Maarten Sch�nfeld]

Thresher/Permit Class LargeSail Sizes
Length: 26.85�
Height: 13.90�
Width: 4.76�

Hi,

I took the data from this thread to cut up a MikroMir Thresher, to create one of the three 'improved' Permits (Flasher, Greenling or Gato). The hull ended up being exactly the same size as the Sturgeon just behind it - no surprise as both should be 292ft3in. The enlarged sail looks gorgeous, I'm only wondering whether the dive planes should be increased in size too?

[Vepr157]

I believe the fairwater planes are the same size on the boats with the tall sails.

[SSNJim]

I think the sail planes are the only thing in common between the 594 long and short hull sail structures. I've never seen a difference between them.

Here's some photos of a 594 stretch surfacing during UNITAS XX:
http://research.archives.gov/description/6352044
http://research.archives.gov/description/6352043

Here's a bow-on comparison of 593 and 614 showing the differences in the width of the sails:
http://www.navsource.org/archives/08/0861409.jpg
http://commons.wikimedia.org/wiki/Categ ... 3)_bow.jpg

[Maarten Sch�nfeld]

I think the sail planes are the only thing in common between the 594 long and short hull sail structures. I've never seen a difference between them.

Thanks, both of you for the note. I'll leave the 'fairwater planes' as they are.

Maarten

[merriman]

...................

[Tom Dougherty]

David,
Great to see you on this forum! A quick question on the Thresher. Years ago Jim Roushey built a Thresher for the Portsmouth Naval Shipyard. In the accompanying article, he mentioned that Thresher never received the 7 blade J-prop, but sank with the 5 blade speed prop still on the sub in early 1963. Do you have any clarity on whether this is so or not?

Best regards,
Tom

[merriman]

David,
Great to see you on this forum! A quick question on the Thresher. Years ago Jim Roushey built a Thresher for the Portsmouth Naval Shipyard. In the accompanying article, he mentioned that Thresher never received the 7 blade J-prop, but sank with the 5 blade speed prop still on the sub in early 1963. Do you have any clarity on whether this is so or not?

Best regards,
Tom

Yeah, ten days and I have not managed to get banned from this forum yet. Must be loosing my touch. Gonna have to work on that.

You've seen the real-life underwater fly-by's (filmed on a range in the Brahma's I think) of an early THRESHER class boat -- clearly sporting the seven-blade wheel. I've heard, but have not been able to definitively discover, that footage was of the THRESHER herself. Which would answer the question. I've never seen a yard or dry-dock shot of these boats with anything but the skew-back wheel at the ass-end.

So .... I don't know.

Model wise, I will only put the five-blader on the SKIPJACK and GW's. All other S5G boats get the seven-blader. I'm currently building 1/72 and 1/96 seven-blade wheels -- doing this again because of the great dope Adam Carlson has dug up on these once super-dupper-double-secrete-probation screws (from The Smithsonian, no less!). http://americanhistory.si.edu/subs/angl ... ming6.html

David

[Vepr157]

You've seen the real-life underwater fly-by's (filmed on a range in the Brahma's I think) of an early THRESHER class boat

Do you know if this footage is on the internet somewhere? I'd love to see it. Thresher had PUFFS on her aft planes until a few months before she sank. I don't know how large the fairings were, but they might be identifiable in the footage.

I have circumstantial evidence that Thresher had a five-bladed screw. It's been reported that Thresher reached 33 knots (same as the Skipjacks) on sea trials, which is not as crazy as it might sound. The wetted area was about the same as the Skipjacks due to the tiny sails of the later class and of course both classes had the same power. However the top speed the later boats in the class was around 28 knots with the seven-bladed skewback. The Skipjacks also had around a 28 knot top speed when fitted with the J-screws. So it seems pretty clear to me that Thresher had a five-bladed screw, at least on trials. I have also heard anecdotes of 637s doing speed trials with five-bladed screws fitted, but I'm skeptical.

If only we had drydock photos of Thresher. It seems that the number of drydock photos is proportional to the square of the number of years in service. I would also kill for a drydock photo of Barb with the 637-esque end-plates on her aft planes.

Jacob

[merriman]

You've seen the real-life underwater fly-by's (filmed on a range in the Brahma's I think) of an early THRESHER class boat

Do you know if this footage is on the internet somewhere? I'd love to see it. Thresher had PUFFS on her aft planes until a few months before she sank. I don't know how large the fairings were, but they might be identifiable in the footage.

I have circumstantial evidence that Thresher had a five-bladed screw. It's been reported that Thresher reached 33 knots (same as the Skipjacks) on sea trials, which is not as crazy as it might sound. The wetted area was about the same as the Skipjacks due to the tiny sails of the later class and of course both classes had the same power. However the top speed the later boats in the class was around 28 knots with the seven-bladed skewback. The Skipjacks also had around a 28 knot top speed when fitted with the J-screws. So it seems pretty clear to me that Thresher had a five-bladed screw, at least on trials. I have also heard anecdotes of 637s doing speed trials with five-bladed screws fitted, but I'm skeptical.

If only we had drydock photos of Thresher. It seems that the number of drydock photos is proportional to the square of the number of years in service. I would also kill for a drydock photo of Barb with the 637-esque end-plates on her aft planes.

Jacob

https://www.youtube.com/watch?v=ZhPHCpeuLOg 1:55 (very poor quality)

David

[Vepr157]

I always just assumed that shot was a model. I guess the waters in the Bahamas must be pretty clear.

How are you able to tell whether it's a seven or five bladed screw? Is there better quality footage out there that you've seen?

Jacob

[merriman]

I always just assumed that shot was a model. I guess the waters in the Bahamas must be pretty clear.

How are you able to tell whether it's a seven or five bladed screw? Is there better quality footage out there that you've seen?

Jacob

That was a spur-of-the-moment find on Youtube. Much better quality stuff has been out there for decades. Yes, they showed the skewed propeller -- that one got past the security guys. I'll keep looking for a better quality version.

I was a Diver in the navy. Once talked with a Photographer's Mate who was a working diver as well and he told me about this range where they would film submerged combat submarines running through a set of gates.

David

[Kagou]

Hi Guys

Anyboby has built the 1/700 models from print3D "Click2detail" ?

Are they great models ?

Pierre

[Vepr157]

Does anyone know if the two shots at the beginning of this video show a real submarine? Ordinarily I would assume it was a model, but I know that there exists footage of Permits taken in the Bahamas that is similar to these shots.

https://www.youtube.com/watch?v=0NvCdtP ... KekF1zZHxg

Jacob

[rshoker]

I just ordered a Thor Design new tool Permit (1/96th) after reading Andrew Karem's "Rig the ship for Ultra Quite. The last deployment of the Plunger. I intend to build her as an RC model. I will pist a review when I get her.

Randy

[Vepr157]

Does anyone have any good photos or more information about the Thresher's BQG-1 PUFFS sonar?

She had a unique array of four hydrophones: (according to Friedman) one near the keel in the bow sonar dome, one aft of the sail topside, one near the keel and SPM in the "waist" ballast tanks amidships, and one topside near the rudder. I was able to find these photos showing the mast for the hydrophone aft of the sail extended:

https://i.imgur.com/jorBGR2.jpg
https://i.imgur.com/21p9kO6.jpg

Apparently this array wasn't very sensitive, and was replaced by a BQG-2A array, which had six arrays, three on each side of the hull: two in the sonar dome, two amidships in the "waist" ballast tanks, and two on endplates (similar, but smaller than the endplates on the Sturgeon-class). You can see the end plates on photos of her wreck:

https://i.imgur.com/nJ7huez.png

According to Friedman, the Thresher's BQG-2A was removed before her loss and put on the Barb during her post-shakedown availability in 1963:

https://i.imgur.com/Y9dDSZR.jpg
https://i.imgur.com/MXuVBnC.jpg

Jacob

[Guest]

I would like very much to build a model of Jack, SSN-605. Unfortunately, I�ve never seen a really good picture of her screws. I�ve seen them on display, off the boat, and I�ve seen a murky underwater pic of them, but nothing clear. Does anyone have any drawings, pics or models of Jack that might help me? Thanks!

[Tom Dougherty]

Since you did not sign in, I have no idea where to send the high resolution versions of these. USS Jack (working model) built by a SubCommittee member some 10 years ago. He used the actual prop blade photos from the Jack propellers, now in Portsmouth NH at the Albacore Museum. I have photos of those as well. Click photos for larger versions.

[Vepr157]

The models Tom posted should give you a very good idea of what they looked like. I only have one grainy photo of the Jack's screws:

https://i.imgur.com/SJ9kItm.jpg

Also, I have these two elevation views of the Jack:

https://i.imgur.com/gTD4PLN.jpg

and a short-hull Permit for comparison:

https://i.imgur.com/Ul2z7Xh.jpg

Besides the screws, the only difference between the Jack and the short-hull Permits was that the Jack's engine room was about 10 feet longer to accommodate the twin-spool direct-drive turbine.

Jacob

[MikeK]

Since you did not sign in, I have no idea where to send the high resolution versions of these. USS Jack (working model) built by a SubCommittee member some 10 years ago. He used the actual prop blade photos from the Jack propellers, now in Portsmouth NH at the Albacore Museum. I have photos of those as well. Click photos for larger versions.

Thanks!

I am a new user, I'm not sure why it logged me in as "guest". I appreciate your help, Tom and Vepr!