The Ship Model Forum

So with Bob's idea in mind we can envision an LCS-1 boat deck taking up the majority of CGN-42's stern. This boat deck would be in the center of the stern with a large amount, maybe 1/3 to 1/2 of the stern Left available, so 1/6 to 1/4 on either side of the boat deck for both NIXIE and the towed TACTAS sonar. I would suggest that the port be TACTAS and the starboard be NIXIE. Does anyone have further suggestion? To anyone's knowledge would there be a problem with putting a boat deck in the stern of a Virginia-class cruiser?

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Proper Preparation Prevents Poor Performance

Again, I may be missing something but couldn't a sailor stand on deck and dangle the recovery line over the side of the ship a few feet above the surface for the RHIB to idle up under and just grab/drop the line onto the RHIB which then attaches the line, circles back out behind the stern to get into position, and gets pulled in?

If you go with a LCS style boat deck, whether on the side or on the stern, the ship must loose virtually all forward motion to launch or pick up the boat.

With the stern ramp method, married with the seaplane float hook up method, the ship slows but does not stop.
To pick up the boat, the ship deploys a sled (today's boogie board) with a high tech rope net attached. The bow of the boat rides up onto the sled where a high tech hook like device on the hull of the boat (Click to enlarge the photo. The point of this photo is to show the hook device on the plane's float, not the dolly the plane is sitting upon.)



engages the net, which allows the shipto pull the sled, with the boat attached, back up the ramp.
There is no lifting of the boat involved.

The line still has to get from the dangle point to inside the boat deck and onto the winch. I am thinking about addressing underway recovery because that's the hard one. If the ship is still the boat can just drive up onto the skids and be manually hooked to the winch and secured as if it is being recovered onto a boat trailer. While the ship is underway, however the winch would have to be used to pull the boat in for the earlier mentioned reasons.

So, I am having a hard time visualizing how we would get the line from the dangle point on the side of the ship to inside the boat deck and into the winch.

If I am understanding your suggestion right, can you elaborate perhaps?

On the not of the San Antonio's RHIB issues, a practiced crew taking 45 minutes to launch or recover a boat is just aweful. I would like to know what the issue is with their equipment, because there is no excuse to take that long.

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Proper Preparation Prevents Poor Performance

A guy takes a hundred foot coil of rope on deck, dangles the end over the side and lets the RHIB grab it, then dangles the other end over the stern where someone else reaches out and hauls it in (use a boat hook, if necessary) to attach to a winch or whatever equipment would be used to pull the RHIB in. Presumably, this would be relatively lightweight nylon line, easily handled. Again, I may be missing something, never having actually done this type of stuff. Just thinking out loud.

Regards,
Bob

I don't know, it must just be me, but does a CGN need to have a stern ramp for boats? It looks like we may wind up with a load of LCS's. Let them deal with getting boats in and out fast since they don't have much fire power any way. Do you plan to put SEAL teams on a CGN? What is the need to launch and recover so quickly? Wouldn't the space and weight be better used for big weapons? I think it's best to use a ship like this to deliver large quantities of munitions. Let this ship be a heavy hitter when it comes to fire power. Have it be really good at BMD, AWS, air and surface warfare. You get to a point when a ship has to do so many different things that it can no longer do any of them well. Should the flight deck be able to handle an Osprey? I'd say, "That's my two cents" but I don't know if my opinion is worth that much.

Bill

Good day! We're examining ways to store boats aboard the ship. We can certainly do the tried and true boat cranes found aboard the DDG-51s, and that may very well be how we go about it. It is the most simple.

As far as putting the heaviest weapons aboard this hull, none of the weapons mentioned in the first post will be sacrificed. With the exception of adding another 35' to the hull for another 64-cell VLS arrangement, turning the ship more onto the strike cruiser concept (CSGN) I am not quite sure how we could make the ship any more heavily armed.

With that being said, we are just examining how a stern boat deck like aboard LCS-1 might be executed aboard the CGN-42. Why be able to rapidly deploy or recover boats? I would suggest that speed, simplicity, effectiveness, and safety are challenges the Navy need to overcome in how it does small boat operations. As it is, all non-well deck platforms take a while to get boats in and out of the water. Most of if not all of them have to come to a stop for long periods of time to perform boat operations not just due to lack of training but also due to equipment limitations.

If we can change the equipment limitations and, of course increase training proficiency, we will be far better off. A RAST type recovery of the boats may make things safer and more effective. You of course need to have the internal space to accommodate a boat deck. There is the possibility of the internal volume at the stern required for a boat deck on the CGN to explore the option. With the custom hull so graciously being custom carved for me, I would not ask that a void be cut in the stern if I were to go with a stern boat deck. I would instead illustrate the capability by fabricating very thin doors onto the finished stern.

It's still up in the air: CG-47 tilt crane, DDG-51 style boat crane, enclosed boat deck like the KDX-IIIs, or a stern boat deck. Do you have an opinion on which might be best?

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Proper Preparation Prevents Poor Performance

So, I guess the RHIB launcher is out? Well, there's another patent application down the drain.

Your reason for a boat ramp makes scene. It's hard to say which other arrangement is best. They all must work since they have been in use for so long. It seems that the stern ramp is out of the norm though. It looks like you would want from two to four boats. Would the helo hangar hold that many? The LCS 1 ramp lowers down into the water. That might be tough due to the hull form difference. The Coast Guard WMSL's have an open stern boat ramp with an over head system to move the boats into side cradles. The original design had two side by side ramps and a stern wedge DDG style. The boats launched out over the wedge. The as build design has the geometry of the wedge built into the bottom of the hull with a pair of sliding doors. The boats are in the water as soon as they clear the doors. It does take up the whole back of the cutter and it only handles two boats. I have no idea how well it works. If that can fit on a cutter and not interfere with steering, it should work on a larger ship. The cutters still have a boat on the starboard side CG-47 style and LCS 1 has a boat on the port side KDX III style, so there must still be some value in that arrangement even though both of them have ramps. Maybe if you go with a stern ramp, say with two boats there, you still might want to have two more boats on the deck. A back up in case the stern doors are damaged I guess.

Bill

Bill,

Your expertise is enlightening. Perhaps instead of either option, both the boats on the side of the ship with a crane and a stern boat deck might be called for. This leads to another set of attractive options to consider. Since it's being done with LCS-1, we know that albeit new it is a practiced capability. This would provide the ship with capacity of up to 4 boats and a water-line access capability.

One is right to ask: "what in the world would a nuclear powered cruiser be doing with SEALs aboard?!"

The answer is: performing SEAL operations. All ships in the US Navy employ SEALs, and yes, that ranges from PCs to CVNs. Like CAPT Potter stated in his book: Electronic Greyhounds: The Spruance-class Destroyers, a ship with a minimum of two 5” guns and a large helicopter hanger and deck was attractive to SEALs. A CGN with a large helicopter hanger, and two 8" guns would be of great interest to SEALs in theater as well, especially in calling for fire and calls for extraction. Sure this would be better done with a DDG armed with 8" guns, but that's another story. One must keep in mind that CGNs and Ticonderoga-class CGs have been utilized in gunfire support roles before.

Following this I would suggest that if it is possible the stern ramp should be able to park two 11meter SWCC RHIBs side-by-side without having to crane or stack them in any special way. Two skid-type cradles (exactly like boat trailers) would possibly be ideal. Even to get them out of the water, the sterns of the cradles could be elevated up on an even keel so the boats could be taken out of the water, maintenance could be performed on them, etc.

This also leads to another question: should the stern be able to ballast down a few feet, not the 10+ of amphibs, but enough to float boats or should the doors on the boat deck close and seal up well enough to where the deck can be pumped dry?

BILL!!! How is the water level managed on LCS-1?

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Proper Preparation Prevents Poor Performance

David,

All of the basics are there in other ship designs for a stern ramp. You just have to figure out which one you like the best.

As to the water management on the LCS 1 ramp, take a look at the stern door photo you posted earlier in this thread. You will see that the stern of the ship is out of the water. You can see it well at the bottom right corner of the transom. You can also see that the ramp is lowered into the water. My guess is they just let the water run out, but I'm sure there is some method to ensure positive water removal.

Bill

How about an telescopic boom style crane (internally mounted in stern mission bay) Just open pod bay doors extend jib of crane with some sort of docking device on it. Pull up under it in RHIB extend docking probes ( or use Electro magnet like in a junk yard.. pick up RHIB by the rollbar??) an hoist back in. No Ballasting required.

Bruce

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building:
1/72 RC USS LONG BEACH CGN9
1/72 RC USS CALIFORNIA CGN36
1/72 RC USS SAIPAN LHA2
1/72 RC USS JOHN PAUL JONES DDG53
1/72 RC USS SHARK SSN591
1/72 RC USS SEAWOLF SSN21
1/72 RC USS ALBANY CG10

Wow. Well, there are telescoping boat booms like that on the sides of ships and the backs handling one boat at a time. They take a little while to launch and much longer to recover. Such a jig would be nice for a boat hanger in the side of the shipm but perhaps not for rapid use.

I would suggest that an electromagnetic recovery jig, causes a lot of logistical issues. What you probably think is a roll bar is really a mast, because boats don't need roll bars...there is nothing to roll against. So you would have to install a highly, highly magnetic roll bar and magnet capable of lifting 19,000lbs out of the water plus the crew and team, about another 2400lbs. So your magnet and roll bar would have to be able to lift about 21000lbs plus about 200 gallons of fuel.

Don't forget: everything else that's magnetic is going to be pulled on with at least 20,000lbs of magnetic force too. All of your weapons, tools, Gurber multi tool on your belt, your belt buckle, etc. and your magnetic compass will probably be ruined and all will be ripped off whatever they are on or in....

I think we will stick with lines and ramps. Even extending arms adds a lot of complication that we really have to question. We need to launch and recovery quickly, hense the boat trailer-like boat skids mounted inside the boat deck where you can hook a line on and winch the boat into the boat deck and onto the skids. Based on Bill's comments about the Coast Guard cutter's stern boat deck needs more examination.

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Proper Preparation Prevents Poor Performance

David,

If you're really interested in launch and recovery, you might obtain a copy of the Dec '09 Proceedings and look at pg.79, "Improving Shipboard L & R (launch & recovery)" which describes a RHIB L&R system called Soft Rail. Basically, it's a system where the RHIB rides up and down "rails" extended from the ship. The neat thing about this is that the "rails" are actually flexible rope that trails from the ship into the water and the force of the water drag on a sort of drogue chute at the end of the rope makes them stiff enough for the RHIB to ride down. It sounds hard to believe but the system was apparently successfully tested on ships in 2007. L&R was conducted at speeds of 10-25 kts. There's even a picture of a RHIB launching. Supposedly, it can work for water level or deck level operations.

I don't know what, if anything, came of it. Maybe it's being used on the LCS?

Here's a link to a detailed paper describing the system along with photos of the system in use:
http://member.navalengineers.org/SiteCollectionDocuments/2008%20Proceedings%20Documents%20(Papers%20and%20Presentations)/Launch%20and%20Recovery%202008/SOFT%20RAIL%20Symposium%20Paper%20Word2003.pdf

Thanks,
Bob

Bob,
Very interesting!

In contrast to the sledmethod, it eliminates the need for a structural ramp. But it does add a few steps to launch and recovery.

Ramp & Sled
A. Launch
1. Launch boat from ramp.
B. Recovery
1. Deploy sled
2. Boat bow rides up on and attaches to sled.
3. Sled and boat are recovered

Soft Ramp
A. Launch
1. Deploy soft rail drogue/sea anchor
2. Launch boat
3. Recover sling ride
4. Recover soft rail
B. Recovery
1. Deploy soft rail
2. Deploy sling ride
3. Boat enters sling ride.
4. Bow man attaches to sling ride.
5. Recover boat and sling ride
6. Recover soft rail.

IMHO:
Soft rail is innovative but does not seem to comply with the KISS principle.
Would permit the use of any warship for boat ops, without impacting ship's boats/davits/cranes.
The higher the ship's deck, the farther out the drogue would have to deploy, impacting ship naneuver options?

Over the last 2 weeks I have been getting pretty deep into the weeds over this boat deck/hanger issue. I have found the problems with the enclosed boat hanger issue San Antonio has been suffering, and the effectiveness of the cranes used aboard FFGs and DDGs. I have found that while the enclosed boat deck would be pretty fun and techno-savvy, but the risks do not seem to out-weigh the benefits. The stern boat deck similar to those of the LCS and new CG cutter seems to be especially effective at rapid launch and recovery, a capability greatly desired by any kind of boat guy, especially the specwar types. Keeping the recovery systems as simple as the FFG/DDG style cranes on and boat skids in the stern you drive up onto is about as simple and reliable as it needs to be. Hopefully the recovery system and doors on the stern are as maintainable as they need to be to be to offer maximum operational reliability and safety.

I know where I can get 1/350 7meter RHIBs does anyone know where I can find 11meter RHIBs?

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Proper Preparation Prevents Poor Performance

I'm not sure which these are in this set 7 or 11 meter. Take a look, PacFront has them in stock.


http://www.pacificfront.com/catalog/pro ... ts_id=3238

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"There seems to be something wrong with our bloody ships today"

Thank you. Those are the normal 7 meter work boats. The 11 meter boats are what i have in mind. I can modify them to be SWCC boats pretty easily. I have been on them plenty of times.

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Proper Preparation Prevents Poor Performance

CIWS: Phalanx Block 1B and RAM

Some contributers to several threads on this wonderful forum have suggested that on new construction only one Phalanx Block 1B and one RAM are necessary for close in weapon support. By the very nature of the ship's structure, this limits the coverage of the ship's critical CIWS weapons an aweful lot. Anyone aware of the facts pertaining to either Phalanx or RAM know that either system has its limitations, and when it goes down for either maintenance or because of a casualty, it is useless. I may be missing something, because I do not understand why they would suggest limiting the ship in such a way.

Does anyone have a suggestion as to how many CIWS (Phalanx and RAM) mounts should be on a ship and why?

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My next question is: why the hell did we even go to the Mk110 57mm gun when the Otto 76mm super rapidfire weapon is so much more impressive and seems to perform better?

76mm:
http://www.youtube.com/watch?v=QrUXDAhP3Fg
(here's a write up, too http://www.otomelara.it/EN/Common/files ... 6-62SR.pdf)

57mm:
http://www.youtube.com/watch?v=D9yCURHi ... re=related

Both seem to do the same thing as far as programming the rounds to detonate at a certain distance. The 57mm is okay and is being used. It certainly has a greater rate of fire, but it is not as effective as the 76mm super rapidfire. Might it have been chosen because of political consideration or is it actually better?

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Proper Preparation Prevents Poor Performance