Northrop Grummans Newest Aircraft Carrier Takes a Bow(Bow laid for newest carrier)

Spacewar ^

[MARKUSPRIME]

The carrier is under construction at Northrop Grumman's Newport News sector, the nation's sole designer, builder and refueler of nuclear-powered aircraft carriers. Weighing 780 tons and made up of 25 steel sections, the upper bow is one of the heaviest crane lifts in the ship's production plan. Newport News began construction on the upper bow unit last February.

"Landing the fully-outfitted upper bow on the ship is a significant milestone in the design and construction of CVN 77, and most importantly, a great team effort by our shipbuilders," said Scott Stabler, vice president for the CVN 77 program at Northrop Grumman Newport News. "We are on track for record shipboard construction progress at launch in October."

[Final Authority]

A former carrier captain once told me, actually, he asked me then gave me the answer. He asked, how many kinds of ships do you think we have in the US Navy? I said, I don't know. He said, the answer is real simple. We have two kinds, submarines and targets.

[Brofholdonow]

This may be fiercely debated, i.e., naming the pride of the USN after an impeached executive who also forwarded secret technology to many of our potential enemies. If this tragic precedent is enacted, we should also launch other naval vessels with monikers such as the USS Benedict Arnold, Julius/Ethel Rosenberg, Whitaker Chambers,as well as some of recent CIA/FBI traitors...Perhaps-if the Justice Department does it's job-Sandy Berger and Jay Rockefeller as well.

[cva66snipe]

Thanks for the pictures and the info. I wasn't exactly sure when they did the Harrier sea trials I just know most of us {in ships company} had not seen them before till 79 or so. They didn't go out with us from 77-80 unless it was after October 80. I saw the ROSIE I'm thinking in early 77 in NNSY Portsmouth. We went back in the yards around mid 78 but I think she was gone to Philly by then. I know our MM1 got some parts off of her.

[finnman69]

Cool pic here

[John O]

SWATH is Small Water Area Twin Hull. Not exactly a catamaran. More like a flat deck placed on two pylons resting on two submarine hulls.

IIRC the design ends up with very good seakeeping characteristics.

I doubt that it would work for something as large as a cvn however. But then again, I don't work in that area. I know when they first started looking at SWATHs (in the 80s) they did a study for CVN's but I don't know the results.

[TalonDJ]

That and fuel use. Plus landing damaged aircraft. A VTOL coming back from a mission low on fuel and damaged can not make a vertical landing. Also most VTOLS are not capable of taking off vertically with a full load of bombs and fuel. Plus there is the risk factor. For the marines VTOLS have the big benefit of operating off of helo carriers there by giving them better teeth and self defense. They compliment conventional aircraft and add an extra capability but are not a total replacement.

[Wombat101]

In that case, I can only envision a monstrosity where most of the gear and infrastructure required for both flight ops and to run the ship is located mostly above decks. God only knows what that does to stability and sea keeping, with that much weight topside (otherwise you no longer have a catamaran or Twin Hull or whatever you want to call it).

It would certainly not make for a very good aircraft carrier and would, in my opinion, negate the very reason you would want SWATH technology incorporated into the design in the first place. I'm not an engineer or ship designer, so I wouldn't know for certain.

[jimfree]

780 tons seems a bit light for a carrier.

Just a tad - aren't most of them about 78,000 tons? Our little frigate PATTERSON (FF-1061) was 4,000 tons.

[Enterprise]

Yeah, I didn't read closely enough. St Patrick's day was to blame. That portion of the article was only referring to the bow. It was one of my DOH' moments.

[Wombat101]

I think that '780 tons" referred to the bow section seen in the accompanyihng photograph.

Of course, tonnage is expressed in a variety of ways;

1. Amount of water, by volume, displaced when the ship is sitting in the water.

2. Metric tons vs. imperial tons

3. Tonnage as an enmumeration of the total volume (cubic tonnage) within the ship (i.e. as if the ship were an empty container).

4. Displacement of water at various "loads" (i.e. empty, with fuel and ammo aboard, etc).

5. GRT (which, I think. not completely sure) is the actual weight in actual pounds.

4.

[Robert A Cook PE]

At that size (1100 plus feet long, with a beam to match), SWATH has little positive effect on stability in high seas. The carrier hull itself is so large that little disturbs it, though of course flight ops are more difficult in extreme seas anyway.

But equally important, the carrier has to be so large, for in-place armor, aircraft fuel, stores, bomb storage areas, and support/maintenance areas, that the small diameter submerged hulls that make a SWATH effective get too large. All of the volume (weight) has to get supported by underwater volume, but that means that the SWATH (basically circular, submarine-shaped) hulls get too deep.

Too deep means that the carrier can't get into drydocks, harbors, ports, or maintenance docks.

[Robert A Cook PE]

In this case, "tons" means structural steel weight. Crane weight capacity for that lift.

[Robert A Cook PE]

SWATH is OK for smaller (frigate-sized) flat-topped hulls, like you pointed out. A small ship sees good advantages in stability, but at a higher cost to build, more water resistance (you need more fuel to go the same distance = more displacement = more weight = even more drag) and with a depth penalty: again, bearable if you have a small ship.

SWATH isn' effective for larger ships, mainly for the displacement answer I gave above, but also because the very large carrier sized ships don't get an advantage from SWATH in sea-keeping. Worse, they pay an extreme penalty in hull weight and complexity and expense of manufacturing and difficulty of construction for limited benefit.

[Robert A Cook PE]

I worked with one of the older carriers (conventional) that had a similarly-shaped sonar bow dome.

[Squantos]

Thanks for the explaination RAC !

Stay safe !!!

[John O]

Thanks. It's been a while since I worked with hull forms at all (and I never worked with them in depth anyway) so I appreciate the info.

[Wombat101]

Thanks.