Ask An Expert- Naval Forces

[desertswo]

Alaska class cruiser rudder modification?

I've always wondered what could have been done for them so I figured i'd ask :). Say the war lasted longer and someone decided the Alaskas needed to handle betterto evade those nasty Long lance torps what could be done? Could dual rudders be done or is that WAY to much work? I was reading about a Schilling rudder and how it improves handling how about that? This isn't meant as an "Alaskas were the best" idea just an idea thats floatin in my noggin :D.

A Schilling rudder, like any other, will only work at max hydrodynamic efficiency if placed directly, or nearly so, aft of a screw. The sort of SHIPALT you are referencing, while not impossible, would have been too expensive and invasive.

[85 gt kid]

It's crap. It's not only crap, it's incredibly silly crap. Let me know when you can get a MK-46 or MK-50 torpedo to do what they showed it doing last night.

You can find stuff like that in any movie/show. I just try to look past that and enjoy the rest of it. Now when you get a movie like American Warships now that's silly crap :puck:.

Thanks for the help guys!

[85 gt kid]

A Schilling rudder, like any other, will only work at max hydrodynamic efficiency if placed directly, or nearly so, aft of a screw. The sort of SHIPALT you are referencing, while not impossible, would have been too expensive and invasive.

So then basically it would still need a dual rudder setup right? Just spit balling ideas that the voices in my head come up with :fish:.

[desertswo]

So then basically it would still need a dual rudder setup right? Just spit balling ideas that the voices in my head come up with :fish:.

Yeah, but it's not like the ship is a total pig in a turn. The CG in which I was Chief Engineer only had one rudder between two screws. If you really want to get around quick, you just put a "twist" on and her head will get around pretty expeditiously. What is a "twist?" Back the screw on the side in the direction of the turn. So a port twist would have the rudder over to port, the port engine backing, and the starboard engine ahead. The more power you use, the faster and tighter she'll turn. If you want to practice, just push a shopping cart the next time you go for groceries. It's the best way I know of, short of the real thing, or an advanced simulator that will give you an example of a what a twist "feels" like when doing it. Oh, and it's also fun! The real thing, not the shopping cart.

[85 gt kid]

Lol i'll keep that in mind thanks desert!

[RustyBattleship]

Re: "The Last Ship". I think they used at least three different ships to portray the Russian Kirov class cruiser. The Iowa was difinitely in the combat scenes as you can tell by the dual 5"/38 gun mounts. With San Pedro so close to the major movie studios, any museum ships there will draw in film crews like a magnet over carpet tacks.

The SS Lane Victory has had several commercials done either on her or as a background. Her engine room was also prominent in "The Sand Pebbles" with Steve McQueen and Mako.

The USS Hornet up in Alameda has been used for commercials and was a co-star in "JAG".

The Iowa has already been used in several movies and TV shows just in the past two years she has been in Los Angeles. It is also ironic that in one episode of "NCIS Los Angeles" she was used to impersonate an Aircraft Carrier (though the Midway is just a hundred miles down the road).

[85 gt kid]

Anyone know the cost of the conversion upgrades to a Boston Class Cruiser?

[USSDD715~DD510~]

I served in the US Navy 1965 - 1968. My last ship The USS Beale DD- 471 was at the end of its life after having proudly served in WW II. We went into Portsmouth Naval Shipyard and they dry docked us. The US Navy wanted to answer the question the poster just asked.

Shipyard workers cut a fairly large square out of the side of the ship to get a "look" at the frame sections.

For the record, ships internally, are usually identified as frame 1, frame 14, frame 36 and so on. Those frames are the ? crosswide ? steel girders, welded to the hull, that represent the strength of the ship. I used to have a photo that I shot of one frame that was, in one spot, 80% missing, due to years of accumulated rust and corrosion. All of us realized that the ship could break apart in rough seas. As a result of the report, the ship was immediately barred from setting sail ( in open seas) again, and immediately placed on a decommissioning list. The best way to access wear and tear, is to cut open a number of "samples" depending on the size of the ship, go in, and see what is there.

In an extremely large ship, in a dry dock, it might be possible to cut holes in, and walk around with a video camera to see "what is what", on smaller ships you have to open sections up somehow and observe. I know that submarines have some sort of similar procedure including specialized ways of determining nuclear reactor "health"

[qaz14595]

The best way to access wear and tear, is to cut open a number of "samples" depending on the size of the ship, go in, and see what is there.

That's exactly how we did it aboard SLATER while we where in Drydock earlier this year for the aft storerooms/magazines that had false decking blocking & restricting access to the bilges.

In the picture you can see the whole process as went in the Depth Charge Magazine; The False decking, the "samples" have been cut out, the resulting condition we found; a few wasted frames, after water blasting & with the framing for the new fiberglass decking installed, lastly just like new; freshly painted red bilges! (Don't have a picture off hand; but just so you all know the rest ended up getting a fresh coat of white too btw)

[RustyBattleship]

I served in the US Navy 1965 - 1968. My last ship The USS Beale DD- 471 was at the end of its life after having proudly served in WW II. We went into Portsmouth Naval Shipyard and they dry docked us. The US Navy wanted to answer the question the poster just asked.

Shipyard workers cut a fairly large square out of the side of the ship to get a "look" at the frame sections.

For the record, ships internally, are usually identified as frame 1, frame 14, frame 36 and so on. Those frames are the ? crosswide ? steel girders, welded to the hull, that represent the strength of the ship. I used to have a photo that I shot of one frame that was, in one spot, 80% missing, due to years of accumulated rust and corrosion. All of us realized that the ship could break apart in rough seas. As a result of the report, the ship was immediately barred from setting sail ( in open seas) again, and immediately placed on a decommissioning list. The best way to access wear and tear, is to cut open a number of "samples" depending on the size of the ship, go in, and see what is there.

In an extremely large ship, in a dry dock, it might be possible to cut holes in, and walk around with a video camera to see "what is what", on smaller ships you have to open sections up somehow and observe. I know that submarines have some sort of similar procedure including specialized ways of determining nuclear reactor "health"

The WW II vintage ship you served on was built to be TRANSVERSALLY framed. Most Destroyers of that era had frames 21-inches apart. Some had a 24-inch frame spacing and some only 18-inches. However, in high seas the hull would still "HOG" and "SAG" depending upon if it was cresting a swell or bridging across the trough between swells. To keep the superstructure from breaking in two, one to two Expansion Joints were installed in the deck houses from main deck on up. Basically the expansion joint was a 6 to 8-inch gap with a rubber trough underneath to direct water over to the sides.

However, as heavy electronic consoles were moved further up into the ship's superstructure (to shorten the length of wave guides and coaxial cables thus increasin efficiency) expansion joints would be in the way. Deckhouse heights were also increased from 8-feet ( 7 1/2-feet on BBs) to 9 and even 10 feet to accomodate large air conditioning ductwork to keep the electronic gizmos cool as well as allowing more room for more electrical cables to feed those gizmos.

So the main structural part of the ship (the hull) was changed to be LONGITUDENALLY reinforced with heavy Tee beams running parallel to the deccks and only about 24-inches apart. That still did not completely prevent hog and sag especially in heavy seas. But it was a step in the right direction as now hulls of combat ships have also changed overall configuration for STEALTH capabilities and actually add more strength by the plating being built out of HSLA (High Strength Low Alloy) steels instead of the old fashioned MS (Medium Steel), HTS (High Tensile Steel), STS (Special Treated Steel) and the Chrome/Nickel HY-80, HY-100 & HY-130 (High Yield) steels.

[blidgepump]

Post # 2398 - Fletcher Thread .....

Copy and Paste from the Fletcher Thread # 2398 ......



"I actually recognized some of the assemblies in that film.

GG and Mr. L this question is poised for your knowledge.

The Expansion joint on a Fletcher - DD how does it work while maintaining a water tight state? "

Is this the expansion joint ?

[RustyBattleship]

Copy and Paste from the Fletcher Thread # 2398 ......



"I actually recognized some of the assemblies in that film.

GG and Mr. L this question is poised for your knowledge.

The Expansion joint on a Fletcher - DD how does it work while maintaining a water tight state? "

Is this the expansion joint ?

As I implied, the deckhouse is literally "cut in two (or three)" sections leaving a gap of at least 4-inches up to 8-inches. Steel framing of angle bars are welded across the underside of the superstructure and welded on both forward and aft sides of the cut.

The bottom flange of the angle bar is drilled with 500 to a thousand (or seems like a thousand) 3/8" bolt holes. Aircraft rubber gasket sheeting is then glued and bolted to the angle framework but dipping a few inches to actually make a trough as well as "stretch" when the hull hogs.

The 2nd to the worst part was shaping the rubber sheeting to make the 90 degree turn from the horizontal deck above to the vertical weather bulkhead. I did work with one shipfitter who had an idea to make those turns out of rubber innertubes that already had a curve molded into them. And it worked too.

The worst part was taking the old rotted out or torn expansion rubber down. On the older ships, at least one of the joints ran through the galley. The overhead and bulkheads had 1" thick fiberglass insulation on them that had to be cut out first before we could start unbolting the rubber from the frame.

We wore full length coveralls, taped all pockets shut with masking tape, taped down our collars around our necks, taped down the cuffs around our boots, wore large scarfs under our hard hats and taped them tight to our faces.

It wasn't the glass fibers of the insulation that we were protecting against. It was the one to two million cockroaches hiding up in the insulation.

Ah! The good old days.

[blidgepump]

Expansion joints ...

Mr. L ,

As I understand, somewhere on the superstructure is an expansion joint ....

Are the joints vertical with a bulkhead, or horizontal with the deck?

[85 gt kid]

Here's a random question. When a ship sinks or partially sinks and it is raised (usually after a year or so) what happens to the inside where it's been immersed in salt water? I've seen pics of the Lexington where they stupidly fill her compartments with water to keep her in place during a storm and she's doing BAD. Granted she stays like this for years but still. Any thoughts?

[RustyBattleship]

Mr. L ,

As I understand, somewhere on the superstructure is an expansion joint ....

Are the joints vertical with a bulkhead, or horizontal with the deck?

Let us assume a simple structure where at amidships the superstructure deckhouse is only one level high from Main Deck to 01 Level (7 1/2 to 8 feet high).

What you will see from the outside on the port and starboard vertical bulkheads looks like a 6 to 8-inch wide steel flatbar that is welded or riveted on only the forward edge. The flat bar covers the gap (about 4-inches) underneath and as the ship hogs and sags (literally bending like the bar spring over the rear axle of your car). The after end of the flat bar merely slides back and forth over the bulkhhead plating. That flat bar will also have a slight knuckle bent into it. In a cross-section view it would look like an alomost flattened out V. This forces the aft (unwelded) edge to press against the bulkhead plating and keep water out.

The 01 level will have the exact same arrangement. As a matter of fact this would be the same configuration even on taller superstructures going up to 02, 03, 04 level, etc.

But it is only the uppermost level and the outermost bulkhead expansion joints that will have a rubber "gutter" bolted underneath. Well, the older ships used bolts and glue to keep the compartments water tight. Later ships from the FFG-7 & DD-963 class ships used an aeronautical rubber that has tremendous stretching capabilities and had little or no bottom "bulge" to make that 90 degree turn from the uppermost weather deck to the outermost weather bulkhead.

The ship's hull does not have such an expansion joint as the hull is designed to be the main structural "BOX BEAM" holding everything together. There are 5 major areas of the longitudinal structure of the hull that require perfect assembly for maximum strength. Picture in your mind a rectangle representing a cross-section of the hull.

The two bottom corners are 90 degree curves and the "string" of shell plating that is built into the hull are called the Bilge Strakes and provide the reinforcement necessary to not only keep that shap but provide room for the bilge keel (which is not part of hull STRENGTH but part of ship STABILITY).

Dead center on the bottom of this rectangle is the main longitudinal strength taken up by the Flat Keel, Vertical Keel and Rider Plate making the keel look like an upper case letter "I".

The upper corners of the hull, on each side, is made up of the Sheer Strake (the upper most strake of shell plating) where it is attached (by rivets or welds) to the Stringer Strake of the plating of the Main Deck.

On the ship shown in your photo (and other pictures further up in this string), you will also see some steel plates about 15-inches wide riveted to the hull. These are at the ends of two hull plates of steel that are NOT welded together. Instead they are secured by the vertical riveted plates officially named BUTT STRAPS. These butt straps also allow some flexibility in the hull as well as crack arrestors.

You will also see some rivet seams running longitudinally almost the entire length of the hull. Again, the shell plating is not welded but the rivet strips not only allow for flexibility but to stop any cracks from running all the way up to the main deck. Therefore the official name of these longitudinal rivet strips are called CRACK ARRESTORS.

As welding material, welding techniques and more accurate weld inspection methods were developed we have been able to eliminate rivets almost completely.

Even the Iowa class Battleships were to show the improvement of welding. The first four ships still used a lot of butt straps and crack arrestors whereas the Illinois and Kentucky were to eliminate almost all of the butt straps but still retain four crack arrestors (2 on each side) in addition to the riveted joint between the sheer strake and stringer strake.

Most of our modern ships do not have any expansion joints in the superstructure (though the Perrys and Spruances should have had them). Due to the advent of having a minimum 15 degree angle of all bulkheads for STEALTH, the superstructure is either as strong as the hull or the material is "elastic" enough to compensate for heavy seas.