The Ship Model Forum

[quote="Woodstock74"]Am I correct to think that the small maneuvering propellers the Russians use are "variable" geometry? That is, they can be planed/rotated for use, and they rotated so the blades are parrallel to travel direction (and lower drag)?[/quote]

There is a photo of the Komsomolets wreck that shows one of the secondary propulsion motors (note these are essentially only for emergency use, like their U.S. and British counterparts):

https://i.imgur.com/Ge0m7OA.jpeg

The blades are rotated to feather as you mentioned, and you can see a circle at the blade root, which is highly suggestive of a controllable pitch propeller.

Jacob

Am I correct to think that the small maneuvering propellers the Russians use are "variable" geometry? That is, they can be planed/rotated for use, and they rotated so the blades are parrallel to travel direction (and lower drag)?

Wow, I'm impressed, that actually looks quite good. I suspect they used these plans, which I believe are quite accurate:

[url]https://i.imgur.com/nDoI73K.png[/url]

Jacob

Takom has released a 1/350 Project 658M (Hotel) SSBN: https://www.1999.co.jp/eng/11135558

[quote="Timmy C"]Here's a close-up of that flag, posted by Capt_Navy on Twitter and credited to Alexandre Meneghini of Reuters. Resembles some kind of Spartan or other Ancient Greek hoplite with a Swordfish on the shield.[/quote]

Good stuff Timmy. That answers that! Thanks.

Not as cool as USS INDIANA's Bad Ass Battle Bass, but still pretty sweet.

Dance

Here's a close-up of that flag, posted by Capt_Navy on Twitter and credited to Alexandre Meneghini of Reuters. Resembles some kind of Spartan or other Ancient Greek hoplite with a Swordfish on the shield.

Russian Nuclear-Powered Submarine Arrives in Cuba:

[url]https://www.themoscowtimes.com/2024/06/12/russian-nuclear-powered-submarine-arrives-in-cuba-a85388[/url]

It's the Yasen Class Submarine Kazan. Wonder what is the black flag / symbol she is displaying on the side of her sail? Re-posted for ease of viewing, copyright rests with original owner:

[attachment=0]AFP__20240612__34WH3EC__v1__HighRes__CubaRussiaWarships.jpg[/attachment]

A dragon perhaps? As that features in the coat of arms of the city of Kazan?

And the Yankee Class screws, which were not skewback and probably emitted a significant "blade rate" low frequency for US sonar detections.

Dave, Mike,
Here are the Oscar propellers photos I have, and are Oscar II.
Oscar I is reported to have (depending on the source) either 4 or 5 blade non-skew screws. Probably similar to the Delta III and Papa 5 blade screws below
These are from Vepr's collection. He would probably answer himself but is busy on his research work.

I appreciate you considering the things I proposed and putting so much work in. Unfortunately pictures of OSCAR I screws are few (and are probably all screencaps from the same movie). I'll keep looking.

Cheers,

Dave

[quote="ssn705"][quote="Woodstock74"]Mikro-Mir doing a Yankee class:

[url]https://www.facebook.com/mikro.mir.dnepr/posts/pfbid0zkCRNofdnpq2UZeRkf9rx9QVwS2eXv9xBuR15BSj9kTgEuLsBXeVxtuSFw9mBpjsl[/url][/quote]

Saw it yesterday. Very exciting. Especially with the hull break that could potentially make STRETCH, SIDECAR and NOTCH more easily possible :)

Planning on doing screws for it (and others I might have mentioned)?

Cheers,

Dave[/quote]

Always a possibility of course. As for the Oscar I and Akula suggestion. The Akula was fairly straight forward but I haven't printed a production level yet, only a handful of prototypes. The Oscar is a pickle and I've been working on it on and off since the summer; without photos to go off of I'm using the Victor screw (the tandem-fixed screw like on the Mike) as a surrogate. And I'm struggling to get anything I like and for now avoiding reevaluating the Mike while I'm at it (but once I crack the Oscar I'll probably look at reworking the Mike).


it is unlike the Mike and more like the Victor but for now I just can't get it to look 'right'. And I'm avoiding reevaluating the Mike, and it'll probably need it once I crack the shape issues I'm running into with the Oscar I. And the shame of it all is that using the Victor screw as a surrogate, there are actually tons of photos from different angles and what I'm running into is a hardstop on my CAD abilities I think, for now.

[quote="Woodstock74"]Mikro-Mir doing a Yankee class:

[url]https://www.facebook.com/mikro.mir.dnepr/posts/pfbid0zkCRNofdnpq2UZeRkf9rx9QVwS2eXv9xBuR15BSj9kTgEuLsBXeVxtuSFw9mBpjsl[/url][/quote]

Saw it yesterday. Very exciting. Especially with the hull break that could potentially make STRETCH, SIDECAR and NOTCH more easily possible :)

Planning on doing screws for it (and others I might have mentioned)?

Cheers,

Dave

Mikro-Mir doing a Yankee class:

[url]https://www.facebook.com/mikro.mir.dnepr/posts/pfbid0zkCRNofdnpq2UZeRkf9rx9QVwS2eXv9xBuR15BSj9kTgEuLsBXeVxtuSFw9mBpjsl[/url]

Another screenshot...

Nice. Thanks Jacob. I love these old movies.

Dave

[quote="ssn705"]Anyone happen to have a picture of OSCAR I with the early tandem screws.

Dave[/quote]

Dave,

See this 1983 Soviet film about Project 949:

https://www.youtube.com/watch?v=Fk29x3u928o

The propellers are at 5:10.

Jacob

Anyone happen to have a picture of OSCAR I with the early tandem screws.

Dave

Jacob,
Great reference. Thanks for posting. The large tank under the pressure hull is certainly interesting.

Dave

[quote="ssn705"]Could be. It is just interesting that they are high on the outer hull. I'm doing an OSCAR II with one side of the missile hatches open (so I'll be scratching some internals), so I'm just trying to decide which way to position the small doors on the side...seems like shut is the way to go.

Dave[/quote]

Yeah, I think closed is fine. It appears that only the limber holes next to the missiles have covers; all the others are open with gratings. You can see some of them open and some closed in this photo of the Orel:

[url]https://i.imgur.com/7olm3hA.jpg[/url]

The limber holes next to the missile tubes are probably to flood and drain the "bathtub," analogous to the VLS bathtub flood holes on U.S. SSNs. These cross-sectional views show the missile bathtub areas (MBTs shown in dark shades):

[url]https://i.imgur.com/Ucd1CV4.png[/url]

These sectional views are pretty illuminating because they show where the flood holes must be. At the keel there is some sort of variable ballast tank (safety, negative, or auxiliary tank?), so the MBT flood holes are not right at the keel. The tops of the MBTs are often within the superstructure (like old U.S. double-hull submarines) and that superstructure needs to flood and drain somehow.

Jacob