What-If CGN-42 Advanced Missile and Defense Radar Cruiser

[Russ2146]

Hey Boatman,
What would you have on a boat deck that would be so affected by vibration from the screws? There would be voids and/or compartments between the boat deck and the hull one of which would contain steering gear/controls. Are RHIBS more delicate?
Has the vibration been quatified?

[navydavesof]

Hey Boatman,
What would you have on a boat deck that would be so affected by vibration from the screws? There would be voids and/or compartments between the boat deck and the hull one of which would contain steering gear/controls. Are RHIBS more delicate?
Has the vibration been quatified?

No, you are right in thinking RHIBS are very, very tough. I don't think the RHIBs are the concern, but anything else might be, but working in there at the same time, all of the odds and ends such as tools and anything lose or delicate you store in a work shop, keeping the boats on the skids (they would be have to be strapped down pretty hard I suggest, etc...but would it even be a problem?

Maybe....or maybe not.

[SumGui]

No, I didn�t also get to do a cruise aboard a Virginia; I did do a tour of Texas before she went into the refit she never came out of (first active USN vessel I went aboard after joining the Navy).


A Chief in a specific space (the kind of space I would later work in, and the Chief would later become my OIC at a different command�) passed the scuttlebutt that the vibration aft was the reason the seal on the helo hanger repeatedly failed. He also mentioned the proposal to add VLS in its place.


There was also talk of proposals which changed out her screws to reduce that vibration, but I have no data rather any of them were actually considered or not.


One can find references to the vibration issues experienced by the fast battleships when they first came out, the solution to minimizing that vibration was alteration of the screws � so logically, the same may have been possible here.

Any 'new build' work on a similar hull, e.g. a CGN-42, I would expect design work to be put forward to solve the vibration issue.

[navydavesof]

This is still fascinating to me. The only reason why I am so readily pursing the stern boat deck is because it seems to be a very good use of the stern area. However, this is only if the stern can accommodate the room necessary to fit two 11 meter boats and a work space. While the stern is pretty big, it is looking like fitting 2x11 meter RHIBs, NIXIE, and TACTAS will be a real challenge and will be a result in a very cramped space.

The hanger probably resulted in why we saw in the original Virginias the NIXIE jammed onto the extreme port side as opposed to being in a comfortable centerline or a little off to the side.

Also, if it means having either a 600 round magazine for the aft 8" gun or having a stern boat deck, I think we will have to eliminate the boat deck and stick with what we can have on the side of the ship.

Man, this is going to be one fantastic build. I cannot wait to get started. Where are the model shops when I need them?!

[navydavesof]

This is the format I will pursue. In the scaled picture the mast might be a little big, but the arrangemet is correct. now it's going to be time to build the super structure while the hull is on its way.

So, the questions I need to answer are:
-Stern boat deck?
-Enclosed or exposed small boats?
-Boats on one or both sides?
-128 VLS or more?
-16 or 32 Harpoons?
-Mk45 Mod4 5"/62caliber guns or Mk71 8"/60caliber guns?

Does anyone have suggestions?

[Russ2146]

Do you have a birdeye view, ex the mast?

Russ

[Steppenrig]

So, the questions I need to answer are:
-Stern boat deck?
-Enclosed or exposed small boats?
-Boats on one or both sides?
-128 VLS or more?
-16 or 32 Harpoons?
-Mk45 Mod4 5"/62caliber guns or Mk71 8"/60caliber guns?

Does anyone have suggestions?

If it were me doing this build, I'd have the boats launch directly astern at a speed no faster than 15-16 knots. For recovery, (12-13 knots) I'd have either a line trailing about 20m astern of the ship, or held on a davit clear of the water which the bowman can take in hand and connect to the boats forward bollard. Once the line is made fast, some sailors can take turns on a capstan or windlass and heave the boat in and up a ramp (like recovering a boat to a trailer). I'd recommend that the line be long if it's trailing so that the boat Coxswain can manoeuvre more easily for the bowman to recover it, or offset out of the ships wake if it's to be dangled clear of the water. The wake of such a large ship is very turbulent and can make driving a small boat difficult. Any faster than 16 or so knows and it becomes dangerous, irregardless of the method.

I'd suggest at least 2 boats for redundancy, and at least 2 decks for the same reason (multiple boats per deck if you want). Enclosed/sheltered boat deck, both for protection against the elements and for privacy in the event of anti-piracy ops etc.

VLS, the more the merrier. 48 Harpoon. Mk71, but I'm fond of the Mk 45 mod4

Dave

[navydavesof]

VLS, the more the merrier. 48 Harpoon. Mk71, but I'm fond of the Mk 45 mod4

Hi, Dave! Thanks for the comments. Why do you prefer the Mk45 Mod 4? It's such a weak sister. My reasoning behind the 8" is the 8" is the smallest round capable of filling the US Navy's needs of anti-ship, effective shore bombardment, and anti-fortification. The 5" is anti-boat and anti-personnel at best

Even AGS is being realized as a waste of space.

...so, I believe a modernized Mk71 MCLWG is the best way to go, especially in a hull this large that offers as much internal space for mount magazines as it does.

[Seasick]

The Mk45 Mod4 127mm/62 is a nice gun. The impossible requirements for ERGM did it in from the start. A fin guided 127mm round with an IR homing can locate a surface vessel and with the primary threat being a fast corvette sized vessel a high fire rate and a large supply of ammunition is perferable to a larger bursting charge. The current 155mm AGS was developed from the 203mm Mk71 gun.

[navydavesof]

A fin guided 127mm round with an IR homing can locate a surface vessel and with the primary threat being a fast corvette sized vessel a high fire rate and a large supply of ammunition is perferable to a larger bursting charge.

The 5" KE-ET round is the answer to anti-boat. It's a 5" version of the 57mm Mk110 rounds.

The current 155mm AGS was developed from the 203mm Mk71 gun.

This is only partly true. They used parts of one of the two Mk71s produced at Dahlgren for testing of the AGS. The entire magazine and loading mechanisms are considerably different. The Mk71 does it the way the Mk45 does it. AGS does it completely different from that.

Unfortunately the 155mm (6-inch) round is still inferior to an 8inch and suffers the same lack of lethality against hard land based targets or ships. Because of the internal mechanics of the AGS it requires twice as much room as the Mk71 and only accommodates 2/3 the ammunition. A Burke DDG would only be able to carry about 100 rounds if armed with an AGS.

The AGS light has been such a mechanical problem BAE has canceled the project.

While technological progress is necessary, sometimes the answer is something we have already produced. The Mk71 is still the best choice.

[navydavesof]

Ladies and gentlemen, I give you:

The beginnings of the hull!

I actually have quite a bit more pictures, and the hull is quite a bit further along. I am just having a horrible time resizing them. Trust me, it is absolutely wonderful. When I get this problem down you, watchers, shall be the firsts to see the hull of the next nuclear powered crusier!

[navydavesof]

I think this digital representation of the Coast Guard's National Security Cutter's stern boat deck is a very good framework for the CGN's possible stern boat deck.

The fitting of two ramps, perhaps separated by a bullhead, with perhaps a work shop just forward of it would offer a lot of benefit. I would suggest this would possibly consume perhaps 14-15 meters in the ship's stern consisting of the 11m boats' length, a catwalk, and work benches and equipment storage area.

Hmmm...interesting.

[navydavesof]

Good afternoon ladies and gentlemen!

This CGN-42 project has been moving along for quite some time, but I have not made very many posts! This is a combined project between myself and a friend of mine who is a fantastic ship builder. He liked the initial stages of the project well enough to offer to build a hull for the new version of the CGN-42, and I will scratch build the super structure.

He has been beating me in progression, that's for sure, but fear not! I shall catch up soon! Here are pictures of his most recent fantastic work. He has completely carved this out of wood and added all parts and pieces individually.

If you have a sharp eye you can see the top of an armor belt in there!

Here you can see the stern has NIXIE, TACTAS, and the small boat stern deck! Oh yeah.

All that I can say is BROVO ZULU! In Navy talk that means "fantastic job!"
As soon as I can alter the properties of some of the earlier pictures I will post early progress pictures of him actually carving out the hull. The progress is really fascinating, especially seeing how it goes from a chipped away block of wood to a smooth hull.

I hope you enjoy. I am certainly enjoying this build. My friend has set the bar pretty high! It has challenged my scratch building abilities. So far I have only had globs of sheet styrene that don't match proper angles, but I will get this down. I can't wait to successfully build this super structure. This CGN-42 is going to be one beautiful beast.

[carr]

Well, I just love this already!! Can't wait to see more.

I see that the Nixie and Towed Array openings are very close to the waterline compared to actual installations on existing ships. Would this cause any water infiltration issues?

I also see that you've added the duckbill to the stern. Have there been any studies on applying this to larger ships? Would it provide the same benefits as on smaller ships or is there some upper limit beyond which it no longer helps?

Are you going to add underwater hull openings/sea chests? I know that level of detail may be outside the scope of a conceptual model. Just curious.

Regards,
Bob

[ex-navy]

WOW!!!!!!!!!!!!!!!!!!
This a Double BZ \\\\\\\

Dave,
outstanding work to your friend who did the hull.. How big is it and what did he use for the wood and is covered in plastic or what... is this a one time deal or can it be reproduced for others.....

[navydavesof]

Hey everybody!

Well, I just love this already!! Can't wait to see more.

I know! I think it's going to be a fantastic build. I hope to get a good portion of the super structure built this weekend.

I see that the Nixie and Towed Array openings are very close to the waterline compared to actual installations on existing ships. Would this cause any water infiltration issues?

Not on the model For reference, the water-line is at the bottom of the boat deck doors. For demnostration purposes I think there is no problem.

I also see that you've added the duckbill to the stern. Have there been any studies on applying this to larger ships? Would it provide the same benefits as on smaller ships or is there some upper limit beyond which it no longer helps?

You might want to look into it, but I am pretty sure LHDs have them now. Since CGs have them I think it is very appropriate here.

Are you going to add underwater hull openings/sea chests? I know that level of detail may be outside the scope of a conceptual model. Just curious.

That's one of the problems with the Virginia-class hull. To our knowledge there are no accurate underwater or drydock photos out and about of it. Do you know of any?

How big is it and what did he use for the wood and is covered in plastic or what... is this a one time deal or can it be reproduced for others.....

1/350 so around 20" I believe. It is carved from Basswood, and there's only one.

Later guys! Thanks for the interest!

[carr]

Stern Flap:
As best I can determine, the stern flap is being installed on Burkes and the LPD-17 class. A trial installation was also done on PC-13 (Cyclone class). I have yet to read of any reason why they can't be installed on larger ships. Fuel savings are said to average 10-15%.

Here's a shot of the flap being installed on USS Cole. Note the height of the towed array.


Here's a shot of a commercial vessel with a small stern wedge and lateral (side) flaps. Same idea, just on the sides near the stern.



Sea Chests & Openings:
I've never seen a docking plan for the Virginias but since this is a WIF you could, if you wished, make up your own. Probably more effort than a concept model warrants!

Regards,
Bob

[navydavesof]

Good afternoon watchers! My team mate in this venture has made more progress on the CGN-42 hull. It is almost finished, and then it's going to be up to me to build the super structure and associated pieces.

Here you can see the armor belt I asked to be include in the hull. To scale it is protrudes from the hull by approximatley 4" and run the length of the critical engineering, CIC, and berting spaces.

What a fantastic job. It's going to be up to me to do work that measures up to this. I plan to build up this super structure in small sections that I can place together. The first is going to be the O-1 level that the super structure sits on in all of the CGN-42 concept photos and the RFI test model at the Naval Academy. Then I will build the forward super structure and hanger as blocks I can place on the O1 level.

I am going to be incorporating a lot of the changes they have made to the Arleigh Burkes in recent years to the structure shape, electronics placement, and mast. Man, is this going to be fun!

[HvyCgn9]

Its gonna look sweet mate!!

Bruce

[navydavesof]

Alright, I am taking a method from the really successful scratch building guys on the board here. I have blown up drawings of the CGN-42 to 1/350 scale, and from here I will be able to draw my own plans based on these dimensions. This drawing is from when SH-2s were still planned for the ships so amongst the many other things like RCS reduction, new mast, different armament, etc, I will have to do a little modification to the landing area to accommodate the SH-60 famliy and expand the hanger a little to accommodate UAVs and associated workshops.

Another thing I still need to determine is whether to keep the RHIBs like DDGs have them or if I should try to enclose them like other countries like the Koreans do. I am open to discussion on interior vs exterior storage of the RHIBs.

Thanks guys.