The Ship Model Forum

by **Tom Dougherty** » Mon Sep 15, 2025 10:53 am

The Sierra II has, as with many Russian submarines, a double hull, and the limber holes along the side would indicate a saddle-like double hull. You can see the Sierra II flattened deck structure, along with the modified sail (form the Sierra I) in these photos.

by **ssn705** » Sat Sep 06, 2025 8:31 pm

For what it's worth, I have the Polar Bear SIERRA II and it is a little squat. Deepstorm says 12.2m for S1 and 12.28 for S2 for beam.

Dave

by **Woodstock74** » Sat Sep 06, 2025 5:14 pm

by **Woodstock74** » Sat Sep 06, 2025 4:32 pm

Sierra II:

by **Vepr157** » Sat Sep 06, 2025 1:41 pm

Jon Warneke wrote:
Hi Jacob,

The plans posted show a Project 945 boat (Sierra 1), while the kit posted is the Project 945A boat (Sierra 2). The Sierra 2 hull is 6.7 feet wider than a Sierra 1, as well as 8.5 feet longer, (40.3 foot beam and 351.6 foot length for the Sierra 1, 47 foot beam and 360 foot length for the Sierra 2) with the same vertical height. This will show the cross section to be oblong along the y-axis when viewed from the bow rather than somewhat circular with the Sierra 1 viewed from the bow.

Jon

No Russian source I have mentions any difference between the beams of the Sierra I and Sierra II; both have the same beam of 12.2 m (40.0 feet). Where did you get the 47-foot figure? I don't see any evidence for this in drydock photos or drawings.

Jacob

by **Jon Warneke** » Fri Sep 05, 2025 2:38 pm

Vepr157 wrote:
Woodstock74 wrote:The cross section on the IronShipwrights model appears like a horizontal oval. It looks very odd. Is this correct?
The outer hull cross-section should be approximately circular like the drawing shows, so that looks way off.

Jacob

Hi Jacob,

The plans posted show a Project 945 boat (Sierra 1), while the kit posted is the Project 945A boat (Sierra 2). The Sierra 2 hull is 6.7 feet wider than a Sierra 1, as well as 8.5 feet longer, (40.3 foot beam and 351.6 foot length for the Sierra 1, 47 foot beam and 360 foot length for the Sierra 2) with the same vertical height. This will show the cross section to be oblong along the y-axis when viewed from the bow rather than somewhat circular with the Sierra 1 viewed from the bow.

Jon

by **Vepr157** » Thu Sep 04, 2025 1:09 pm

Woodstock74 wrote:The cross section on the IronShipwrights model appears like a horizontal oval. It looks very odd. Is this correct?

The outer hull cross-section should be approximately circular like the drawing shows, so that looks way off.

Jacob

by **Woodstock74** » Tue Sep 02, 2025 8:03 pm

The cross section on the IronShipwrights model appears like a horizontal oval. It looks very odd. Is this correct?

by **Tom Dougherty** » Sat Aug 02, 2025 2:30 pm

Just received my Iron Shipwrights Sierra II today. Hefty chunk of resin!
What was your question?

by **Woodstock74** » Fri Aug 01, 2025 7:05 am

Anyone else pick up Iron Shipwrights new Sierra I/II kits? I have some questions about hull shape/cross section. Will post pictures later.

by **Vepr157** » Tue Apr 15, 2025 3:38 pm

Woodstock74 wrote: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)?

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

by **Woodstock74** » Sun Apr 13, 2025 7:46 pm

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)?

by **Vepr157** » Fri Dec 06, 2024 1:50 pm

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

https://i.imgur.com/nDoI73K.png

Jacob

by **Timmy C** » Thu Dec 05, 2024 12:35 am

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

by **Mr. Church** » Sat Jul 06, 2024 12:06 pm

Timmy C wrote: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.

Good stuff Timmy. That answers that! Thanks.

by **ssn705** » Sat Jun 15, 2024 8:42 pm

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

Dance

by **Timmy C** » Thu Jun 13, 2024 8:59 pm

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.

by **Mr. Church** » Thu Jun 13, 2024 2:45 pm

Russian Nuclear-Powered Submarine Arrives in Cuba:

https://www.themoscowtimes.com/2024/06/ ... uba-a85388

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:

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

by **Tom Dougherty** » Thu Dec 14, 2023 9:56 am

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

by **Tom Dougherty** » Thu Dec 14, 2023 9:47 am

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.