The Ship Model Forum

The Ship Modelers Source
It is currently Thu Mar 28, 2024 3:13 pm

All times are UTC - 6 hours [ DST ]




Post new topic Reply to topic  [ 413 posts ]  Go to page Previous  1 ... 17, 18, 19, 20, 21
Author Message
PostPosted: Tue Jul 26, 2022 1:51 pm 
Offline
User avatar

Joined: Sun Mar 13, 2005 11:51 am
Posts: 2406
Location: Belgium
The other classes do not have pods, however I believe it may have to with one of the Sovs main roles, shore bombardments. The pods may be there to help them keep position for shore bombardments with the two double 130mm's.
The other classes don't have such a role of course.
May also have helped for mooring as I've heard they (Soviet Navy) rarely used tugs to moor, but then you'd expect the same pods on other designs of that time...

_________________
The merchant shipyard


Top
 Profile  
Reply with quote  
PostPosted: Thu Jul 28, 2022 2:09 am 
Offline
User avatar

Joined: Mon Jan 10, 2005 1:21 pm
Posts: 3374
Location: equidistant to everywhere
Hmmm, I believe even in WWII, naval shore bombardment did not require the ship to come to a dead stop and maintain perfect station. So I suspect the sovremennys didn’t need such precise station keeping either for shore bombardment.

The propulsion pods are neat, but their rationale seems a bit of mystery.

_________________
Assessing the impact of new area rug under modeling table.


Top
 Profile  
Reply with quote  
PostPosted: Thu Jul 28, 2022 5:29 pm 
Offline
User avatar

Joined: Mon Jan 10, 2005 1:21 pm
Posts: 3374
Location: equidistant to everywhere
Another observation, over the last century rudders on ocean going ships seems to me to generally evolved towards higher aspect ratio, that is to say the front back dimension of the moving part of rudder tend to shrink relative to the up and down dimension. So rudders tend to become narrower but deeper.

This is understandable because high aspect airfoil tend to suffer less from tip effect and is thus more efficient and create less drag for the desired effect the generate.

But the Soviets seem to be unique in defying this trend. Udaloy, sovremenny and Slava all have low aspect ratio rudders more reminiscent of big centerline rudders seen on big ships built before the 1950s.

_________________
Assessing the impact of new area rug under modeling table.


Top
 Profile  
Reply with quote  
PostPosted: Fri Jul 29, 2022 9:27 am 
Offline
User avatar

Joined: Sun Mar 13, 2005 11:51 am
Posts: 2406
Location: Belgium
I guess the battleships of the past didn't have to be as accurate as a Sov with a much smaller calibre. In the end accuracy is everything nowadays, so I wouldn't dismiss it entirely.

Their rudders are like that for easier manoeuvering, the configuration with a single rudder and twin props is the worst possible one for manoeuvering as the rudder only enters the props thrust at larger angles. By making the rudder longer, it (partially) enters that thrust field faster. A rudder without a propeller directly forward of it, is generally useless, also the reason why rudders don't work when running the engine astern.
Manoeuvering wasn't really their priority during design phase I guess.

_________________
The merchant shipyard


Top
 Profile  
Reply with quote  
PostPosted: Fri Aug 26, 2022 11:40 pm 
Offline
User avatar

Joined: Mon Jan 10, 2005 1:21 pm
Posts: 3374
Location: equidistant to everywhere
2 questions regarding the Udaloy II class destroyer Admiral Chabenanko:


1. On the Chabenanko. the sides of the forward superstructure block at main deck level contain two large cutouts screened by what appear to be mesh or fine grating. The area covered by the grating is located directly behind the big P-270 moskit/Ss-N-22 sunburn missile launchers.

These grating does not correspond to any ventilation or air intake on Udaloy I ships. There is no reason I can see why Udaloy II will need some huge new vents that Udaloy I didn’t need. So my suspicion is these grating do not cover any real vents in the superstructure. Rather they probably just afford some additional protection to an semi-enclosed area above the whether deck created by blast deflector behind the Moskit launchers. So the area behind these gratings is not properly inside the superstructure, buy just a sort of screened promenade on the weather deck.

If that is correct, then on the trumpeter model I intend to cut away the molded mesh pattern on the superstructure surface that close off these cut outs, replace it with a fine photo etch mesh, and scratch build the true sides of main superstructure behind the mesh.

Can anyone point me to any on-board photos showing this part of the admiral Chabanenko?

2. On Udaloy I class ships, the quadruple torpedo tubes are exposed above deck just behind the break of f’c’stle and fire over the side of the ship. There is a pivoting reload cradle right behind the torpedo tubes. Presumably the reload torpedo can be placed on carts at the mid-ship underway replenishment station via the use of the prominent crane, and then shuttled around the deck on rails until they can be located next to the reload cradle Where they can be pushed up through the pivoting reload cradle to be aligned with the individual torpedo tubes and be pushed into the tubes. On the Chabanenko, the break of f’c’stle has been moved aft to enclose the torpedo tubes, so the torpedo tubes are now completely below deck and normally protected from weather. They fire instead out the side of the ship through doors that open upwards, like on the Slava and Kirov classes. Being completely enclosed below deck, it would seem the Udaloy 1 method of reloading tubes via replenishment station and trolley rails around deck would not work unless there is some big door at the break of,f’c’stle that would enable the torpedo carts to be pushed through the break of f’c’stle. On the trumpeter model, there is only a normal sized water tight door. The cart rails stop and does not go in through the break of f’c’stle. Yet it clearly depicts a pivoting reload cradle straddling the cart rails right behind the f’c’stle break, where it could not possible play a role in loading the torpedo tubes. So I think trumpeter clearly merged features seen in Udaloy i with known layout of Udaloy ii and then added some conjectures where it had no firm information, , without realizing the mixture of features it depicted can’t be but nonsense, because the Udaloy I features it borrowed can’t work with the Udaloy ii configuration it depicted. My guess is the break of f’c’stle isn’t completely enclosed as depicted by trumpeter, and accessible only through a standard size water tight door. Rather it is open to the back, So the torpedo tubes are enclosed outboard by the hull side, protect4d overhead by the extended f’c’stle deck, but not enclosed to the rear. Does anyone know of any photos showing close up of the break of f’c’stle on udaloy ii Adm Chabanenko, preferably seen from the rear?

Thanks.

_________________
Assessing the impact of new area rug under modeling table.


Top
 Profile  
Reply with quote  
PostPosted: Fri Aug 26, 2022 11:59 pm 
Online
User avatar

Joined: Mon Jan 10, 2005 6:00 pm
Posts: 12138
Location: Ottawa, Canada
Can't help with the first query, but to the second query: you're right, it's one large barn-door-style hatch and two circular objects outboard.

See following Getty's Images photos:

https://media.gettyimages.com/photos/-i ... =2048x2048
https://media.gettyimages.com/photos/-i ... =2048x2048
https://media.gettyimages.com/photos/-i ... =2048x2048
https://media.gettyimages.com/photos/-i ... =2048x2048 (This one's the best shot)
https://media.gettyimages.com/photos/-i ... =2048x2048
https://media.gettyimages.com/photos/-i ... =2048x2048

_________________
De quoi s'agit-il?


Top
 Profile  
Reply with quote  
PostPosted: Sat Aug 27, 2022 8:10 am 
Offline
User avatar

Joined: Mon Jan 10, 2005 1:21 pm
Posts: 3374
Location: equidistant to everywhere
Thanks, Timmy!

_________________
Assessing the impact of new area rug under modeling table.


Top
 Profile  
Reply with quote  
PostPosted: Sun Aug 28, 2022 11:45 am 
Offline
User avatar

Joined: Mon Jan 10, 2005 1:21 pm
Posts: 3374
Location: equidistant to everywhere
I observed something interesting and curious from numerous onboard photos of Russian destroyers and cruisers. Using the rungs of the railing as a scale, it appears to me that Russian destroyers, cruisers and even the huge 28000 ton Pytor velickiy, all use bollards and fairleads of apparently same size and design. They also seem to have more or less the same number of bollards and fairleads regardless of the size of the ship. One would think bigger ships would need bigger bollards and fairleads for stronger lines able to resist greater pull, or failing that more bollards and fairleads?

Does anyone know if my observation is incorrect?

Also, it appears to me Russian warships uses smaller anchors than might be expected for ships of their size. Using known height of hull in dry dock as a scale and measuring from photographs of the ship in dry dock with its anchor chained played out and anchor sitting upright on the floor of the dock nest to the ship’s bulbous bow, it appears to me Pyotr velickiy uses anchors of the same size as and very similar design to the 4.5 ton stern anchors on the Bismarck. 4.5 ton anchor is rather puny for a 30000 ton ships, no?

USS Alaska, the WWII era american large cruiser similar in size to the Pyotr Velickiy, had 14 ton anchors.

_________________
Assessing the impact of new area rug under modeling table.


Top
 Profile  
Reply with quote  
PostPosted: Wed Sep 07, 2022 6:59 am 
Offline
User avatar

Joined: Sun Mar 13, 2005 11:51 am
Posts: 2406
Location: Belgium
First point is correct, however, it might be that the actual bollards on the smaller ships are on the large side... Also, bollard dimensions are not always directly related to their holding power, the main item regarding holding power is what's below deck. You can put a very large bollard on a normal deck plate and it will be simply ripped out by a small force. It's the framing below that deck plate that creates the bollard's holding power.
It's also somewhat a choice during construction, I know from experience that two similar sized LNG carriers had on one of them 72t SWL bollards, while the other one had 100t SWL bollards and they were the same size, so the forces acting on them during a moored period would be quite similar. So practically during construction they opted for a bit more safety on one of them. It also depends on whether you are going to tow on the bollards or only moor on them.

For anchors it's the same thing, the calculation depends on how much force you are going to have on your vessel with the wind from the bow. I didn't calculate anything, but I can imagine the wind force on a Tico or Spruance would be quite large compared to a similar sized vessel with a more sleek superstructure (a Slava class for example).
Additionally you have the type of anchor (high holding power or not) and the chain, as a lot of holding power from an anchoring system is actually created by the weight and drag of the pile of chain you put on the bottom rather than the anchor itself. So a smaller anchor with a slightly larger chain may have an equal or better holding power. Or they may simply have a different rule regarding how much chain they pay out in relation to the depth they anchor in.

_________________
The merchant shipyard


Top
 Profile  
Reply with quote  
PostPosted: Sun Jan 15, 2023 8:36 am 
Offline

Joined: Tue Jan 21, 2014 4:44 pm
Posts: 58
Location: Italy
Dear all,
Attached you can find the pictures of 2 Sovremenny under demolition (screenshot from a video I found). I encircled in red an object that I do not understand what it can be. Can anyone help me? I haven’t found any other image of it, neither in operation nor under demolition. It seems something folded or maybe not. If anyone has any idea, they are welcommed.


Attachments:
4E0080DF-AAC0-484F-9972-C51A4490982A.jpeg
4E0080DF-AAC0-484F-9972-C51A4490982A.jpeg [ 2.27 MiB | Viewed 855 times ]
Top
 Profile  
Reply with quote  
PostPosted: Sun Jan 15, 2023 10:37 am 
Offline

Joined: Tue Jun 14, 2005 6:23 am
Posts: 3689
Location: Bonn
The answer in another fora was that this could be one of the 600 kW diesel generators:
https://www.forum-marinearchiv.de/smf/index.php/topic,38904.0.html

Do you know which ships these are and when they were photographed?

_________________
Image


Top
 Profile  
Reply with quote  
PostPosted: Sun Jan 15, 2023 3:23 pm 
Offline

Joined: Tue Jun 14, 2005 6:23 am
Posts: 3689
Location: Bonn
There at this forum, they also identified the two ships: Bezuderzhnyy (Безудержный, 406) and Gremyashchiy (Гремящий, 404) in Severomorsk in 2018.

Probably the source for the photo:
https://www.youtube.com/watch?v=_SMIvHumrYY

_________________
Image


Top
 Profile  
Reply with quote  
PostPosted: Tue Jan 17, 2023 5:53 pm 
Offline

Joined: Tue Jan 21, 2014 4:44 pm
Posts: 58
Location: Italy
Dear Maxim,
Really really thanks. I had seen the first video (from which i had taken the screen shot), but the second video is better, since it allows different points of view. The video captured my attention more than one year ago, but the modelling time is very little and therefore only now i came to try to replicate that strange object, that was identified as, possibly, a diesel 600 kw engine. Please thank the german people of the other forum for their kind, quick and proactive reply. Indeed the replica of that device is challenging, since any enlarged picture gives very temptative borders to its shape.


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 413 posts ]  Go to page Previous  1 ... 17, 18, 19, 20, 21

All times are UTC - 6 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 29 guests


You can post new topics in this forum
You can reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Jump to:  
Powered by phpBB® Forum Software © phpBB Group