US Navy News and updates

[RobWilliams]

Good progress on USS Gerald R Ford with the lift of the upper bow section on the 9th

[nomedia="http://www.youtube.com/watch?v=iAfAatm3A-s"]Upper Bow Lift of Gerald R. Ford (CVN 78) - YouTube[/nomedia]

The length of the flight deck of the nuclear-powered aircraft carrier Gerald R. Ford is complete following the addition of the ship's upper bow section on April 9 at Newport News Shipbuilding (NNS). The upper bow extends the overall length of the carrier to its full size, which is 1,106 feet—equal to a 75-story building lying on its side.

Reading the HII news release about it, the ship now stands at being 96% structurally complete

Huntington Ingalls Industries

Weighing 787 metric tons and comprising 19 steel sections, the addition of the upper bow brings Ford to 96 percent structural completion. The carrier construction team began construction on the upper bow unit in December 2011. Ford has been under construction since November 2009.

"Placement of the upper bow gives our entire shipbuilding team a great sense of accomplishment," said Rolf Bartschi, NNS' vice president, CVN 78 carrier construction. "We have now structurally erected the flight deck to its full length."

Gerald R. Ford is being built using modular construction, a process where smaller sections of the ship are welded together to form large structural units, equipment is installed, and the large units are lifted into the dry dock. The upper bow unit is the 475th unit erected out of 496 used to build the carrier. It also is the 160th superlift to erect out of the 162 scheduled. It joins the lower bow section that was set into place on May 24, 2012, in the dry dock. The lifts are accomplished using the shipyard's 1,050-metric ton gantry crane, one of the largest in the Western Hemisphere.

Gerald R. Ford represents the next-generation class of aircraft carriers. The first-in-class ship features a new nuclear power plant, a redesigned island, electromagnetic catapults, improved weapons movement, an enhanced flight deck capable of increased aircraft sortie rates, growth margin for future technologies and $4 billion reduced total ownership cost compared to a Nimitz-class aircraft carrier. The ship is scheduled to launch later this year.

Good to see such progress going on, glad to hear she'll be launched by the end of the year & I hope they buy the whole 10. It does seem a bit doom and gloom to forcast say only a buy of eight when that sort of decision will be taken in the 2020's.

 

[alexsa]

This question for Alexsa, Swerve and StobieWan: Did you guys take into consideration that the Independence is probably 80% made of Aluminum therefore it is an 2800 ton ship? Would a lighter ship made of Aluminum has a lower weight capacity than for example the Freedom which is made of Alloy Steel? Also, being the Independence is an Trimaran, equating to more space, therefore it would be able to carry more load?

Absolutley...... and the light wieight high speed focused construction has implications for more severe conditions and lighter ships with alloy construction are often limited. Also displacement is submerged volume. Ships are designed to a given range of submerged volumen combined with their block co-officient for a give desired performance (the block coef being the proportinate area of a block - beam length and depth - the hull form takes up). A ship designed to displace max 2000 to 3000 tonnes has much less capacity to carry than on that can displace 3000 to 4000 tonnes.


It is essential to look at the light loaded mass of a ship. This is the mass of the hull and equipment only. All other gear (weapons, fuel, crew, their gearm their food, thier water, waste facilities, missions modules, helicopters .... and all their gear....). adds to that mass until ou get to the designed max displacement.


The USN have a use for this adpative platform and the support to make it work but don't think that it is the panacea to all GP frigate needs. The need for speed has a massive impact on uplift weight and persistence.

 

[alexsa]

Yes, I understood what Stovie's response. However, nobody has responded relative to whether the Independence being made of steel and therefore will weigh more gives it the capacity to carry more load against what it is made currently of aluminum? There is something missing in this equation that I can't find the answer?
Lighter material would then be a disadvantage? I would think it is NOT in aircraft or vehicle designs? Please respond. Thanks.

I you were to construct the ship from steel you uplift capacity will drop as the weight of the hull will increase immersion. Remember the SPACE you all note these ships have is because they have LESS MASS.


You cannot suggest that these ships can carry much more because they are light as that is what gives them the volume and desired speed. Have a look at a 120m feeder container ship with a speed of 20 knots (2 knots above the sustainable speed of LCS) and note the deadweight and range if you want to see the difference.


And before I get howled at I am not suggesting a box boat is a better LSC it is just indicative of capacity.

 

[alexsa]

Stobie, I appreciate your good effort and explanation. However, I still believe that General Dynamics found a way to increase the effective load carrying capacity of the Independence with the trimaran hull design. Again I am not a marine engineer or architect or I'm not privy to the detailed design of the ship. However, I would like to offer what I think about what we're discussiong. The Archimedes theory still applies based on direct correlation between weight and displacement, and in addition to the surface area of the ship in contact with the water must also be considered in the equation. The Independence has a big/large contact area with water, and as long as the relative center of gravity is maintain in relation with the load, I think bouyancy is maintained and the ship is able to carry considerable amount of load greater than its dead weight?

Sorry I am responding as I read and noted that ASSAIL and STOBIE have given you a pretty good outline of the physics that covers this. To suggest that GD have found a way of increasing deadweight without increasing the wetted area (submerged volume) is simply bollocks.


Suggest you do some reading on the subject.... perhaps D.J Eyres (an introduction to ship construction), A.R Lester (Merchant ship stability .... still applies to warships unless they are lighter than air), A.R Derrett (Ship stability) or Ship Design and Construction edited by Tagget and written for SNAME.

 

[Volkodav]

Sorry I am responding as I read and noted that ASSAIL and STOBIE have given you a pretty good outline of the physics that covers this. To suggest that GD have found a way of increasing deadweight without increasing the wetted area (submerged volume) is simply bollocks.


Suggest you do some reading on the subject.... perhaps D.J Eyres (an introduction to ship construction), A.R Lester (Merchant ship stability .... still applies to warships unless they are lighter than air), A.R Derrett (Ship stability) or Ship Design and Construction edited by Tagget and written for SNAME.

Haven't TKMS patented a solution of sorts, with a torpedo shaped submerged hull increasing wetted area while maintaining the minimum cross section actually piercing the water?

 

[StobieWan]

The USN have a use for this adpative platform and the support to make it work but don't think that it is the panacea to all GP frigate needs. The need for speed has a massive impact on uplift weight and persistence.

Exactly - if you (at the other end of the spectrum) accepted a max speed of 25-26 knots on a 130-140 metre conventional hull, you could get a much cheaper CODAD platform that could burble along for 7,000 miles at 15-18 knots and a displacement a couple of thousand tons more. You'd not get the space on the landing deck or as much room for the internal bays but you'd have all the reserves you wanted for missile silos, bigger radar.

But they'd be different ships...for a different job

 

[alexsa]

Haven't TKMS patented a solution of sorts, with a torpedo shaped submerged hull increasing wetted area while maintaining the minimum cross section actually piercing the water?

For performance and resistance yes but it does not change the basic principal of displacement. Bulbous bows had a major impact of fuel use and limiting hull speed but did not impact on the basic floatations equation. The only craft that achieve this are planing vessels, air cushion vessels and hydrofoils.

Essentially any mechanism that can provide hydrodynamic lift (reducing wetted area) can change the equation but the impact of that is you need the power to creat the lift. When you are sitting stopped in the water.... No difference.

Cheers

 

[db2646]

Sorry I am responding as I read and noted that ASSAIL and STOBIE have given you a pretty good outline of the physics that covers this. To suggest that GD have found a way of increasing deadweight without increasing the wetted area (submerged volume) is simply bollocks.


Suggest you do some reading on the subject.... perhaps D.J Eyres (an introduction to ship construction), A.R Lester (Merchant ship stability .... still applies to warships unless they are lighter than air), A.R Derrett (Ship stability) or Ship Design and Construction edited by Tagget and written for SNAME.

Yes indeed, I can read all the books that you listed. Thank you for pointing that to me. I'm still reading the equation: Weight = Displacement. Therefore, if I changed the ships contruction to all carbon/alloy steel, then I increased the ship's weight, therefore I increased the load capacity?

 

[Humming Drone]

Not exactly.

Displacement is the weight of the water that a ship displaces.

Let's assume 2 identical ships - same design, identical hulls, etc. Assume they are made of an ideal material with a 0 weight - ships themselves weight nothing.

Edit: I read my post and realize that I should be smacked with a physics book, and more than a few other disciplines, but, oh well. I'll just add couple more lines to sink deeper .

Let's drop 10000 tons weight on each ship and observe that that is the maximum that this design can theoretically take and stay afloat because
When in the water they (ships) can displace a volume of water that (volume of water x density of water = weight of water) equals 10000 tons. That is the weight that each of those identical ships can take onboard and stay afloat ( to all the ship guys - don't beat me yet, this is an ideal physical scenario, work with me here )

Now, let's replace material for ship 1 with, say steel, and material for ship 2 with aluminum. The weight of material used on ship 1 is going to be, to throw a number, 6000 tons, and weight of material for ship 2 would be, hmmm, let's make it 3000 tons.

Therefore, ship 1 can take on 10000-6000=4000 tons, and ship 2 can take on 10000-3000=7000 tons. Same design, same hulls, same internal space, etc.

I cut a lot of corners in this post, but I hope this helps to clear the concept.

Best Regards,
HD

 

[db2646]

Not exactly.

Displacement is the weight of the water that a ship displaces.

Let's assume 2 identical ships - same design, identical hulls, etc. Assume they are made of an ideal material with a 0 weight - ships themselves weight nothing.

Edit: I read my post and realize that I should be smacked with a physics book, and more than a few other disciplines, but, oh well. I'll just add couple more lines to sink deeper .

Let's drop 10000 tons weight on each ship and observe that that is the maximum that this design can theoretically take and stay afloat because
When in the water they (ships) can displace a volume of water that (volume of water x density of water = weight of water) equals 10000 tons. That is the weight that each of those identical ships can take onboard and stay afloat ( to all the ship guys - don't beat me yet, this is an ideal physical scenario, work with me here )

Now, let's replace material for ship 1 with, say steel, and material for ship 2 with aluminum. The weight of material used on ship 1 is going to be, to throw a number, 6000 tons, and weight of material for ship 2 would be, hmmm, let's make it 3000 tons.

Therefore, ship 1 can take on 10000-6000=4000 tons, and ship 2 can take on 10000-3000=7000 tons. Same design, same hulls, same internal space, etc.

I cut a lot of corners in this post, but I hope this helps to clear the concept.

Best Regards,
HD

All agree with Humming Drone's calculation or analysis/illustration? He doesn't realize it but he is basically agreeing with my theory? For the same basic configuration, the lighter ship is capable of carrying more load.

 

[StobieWan]

All agree with Humming Drone's calculation or analysis/illustration? He doesn't realize it but he is basically agreeing with my theory? For the same basic configuration, the lighter ship is capable of carrying more load.

Um. What you said a page back was
"However, nobody has responded relative to whether the Independence being made of steel and therefore will weigh more gives it the capacity to carry more load against what it is made currently of aluminum? There is something missing in this equation that I can't find the answer?
Lighter material would then be a disadvantage? I would think it is NOT in aircraft or vehicle designs? Please respond. Thanks."

Which is about the opposite of what you're now saying.

 

[db2646]

Um. What you said a page back was
"However, nobody has responded relative to whether the Independence being made of steel and therefore will weigh more gives it the capacity to carry more load against what it is made currently of aluminum? There is something missing in this equation that I can't find the answer?
Lighter material would then be a disadvantage? I would think it is NOT in aircraft or vehicle designs? Please respond. Thanks."

Which is about the opposite of what you're now saying.

Excuse me, but that was not the case. I'm always advocating that the Independence can carry more load inspite of the fact that it is lighter than ships of similar size, etc. Everyone is equating weight to displacement...meaning the heavier the ship in the water, therefore it is more capable of carrying more load. This is counter-intuitive just like I've been saying all along because everyone is used to steel construction...equating more weight to capability to carry more load. Please read my previous posts and understand what I was saying. Just don't be selective to give it a different meaning.

 

[Humming Drone]

You said

Yes indeed, I can read all the books that you listed. Thank you for pointing that to me. I'm still reading the equation: Weight = Displacement. Therefore, if I changed the ships contruction to all carbon/alloy steel, then I increased the ship's weight, therefore I increased the load capacity?

more specifically, "[..] I increased the ship's weight, therefore I increased the load capacity?"

I replied to that post.

 

[alexsa]

Excuse me, but that was not the case. I'm always advocating that the Independence can carry more load inspite of the fact that it is lighter than ships of similar size, etc. Everyone is equating weight to displacement...meaning the heavier the ship in the water, therefore it is more capable of carrying more load. This is counter-intuitive just like I've been saying all along because everyone is used to steel construction...equating more weight to capability to carry more load. Please read my previous posts and understand what I was saying. Just don't be selective to give it a different meaning.

If you have read those books then go to the secition on mass required to submerge more of the hull (known as TPC). The light weight hull form with a low block coeeficient will take a lot less weight to submerge more of the hull form with a resultant increase in wetted area and resistance ............... this affects your performace which is the rational behing the LCS. It has a very low carrying capacity (uplift) compared to a conventional hull.


Build it out of steel and it would be deeper and simply would not work as intended so the suggestion that you get more carrying capacity than a comparable steel ship is moot. A comparable steel ship of 124m simply would not use this hull form. Your standard 114m Frigate has a maximum displacement for just under 4000 tonnes which is considerably more thatn the LCS. The conventional hull will run out of space before running out of carrying capacity. LCS has space to burn but low mass carrying capacity.


Regardless of material of construction if you bury the hull deeper in the water resistance goes up and the power to achieve the desired speed increases as does fuel burn. The deadweight of LCS is quire low for a ship of this size and volume and this reflects the performance. Bury it too deep and it operations will be severly curtailed.


Why is this important ....... well if runs to the adaptability provided by mission modules and weapons packages............. any weight you add in changing the design (up gunning) comes off the deadweight. Hence the comment about GP frigates.


I sense you have not read the books in question.

 

[db2646]

If you have read those books then go to the secition on mass required to submerge more of the hull (known as TPC). The light weight hull form with a low block coeeficient will take a lot less weight to submerge more of the hull form with a resultant increase in wetted area and resistance ............... this affects your performace which is the rational behing the LCS. It has a very low carrying capacity (uplift) compared to a conventional hull.


Build it out of steel and it would be deeper and simply would not work as intended so the suggestion that you get more carrying capacity than a comparable steel ship is moot. A comparable steel ship of 124m simply would not use this hull form. Your standard 114m Frigate has a maximum displacement for just under 4000 tonnes which is considerably more thatn the LCS. The conventional hull will run out of space before running out of carrying capacity. LCS has space to burn but low mass carrying capacity.


Regardless of material of construction if you bury the hull deeper in the water resistance goes up and the power to achieve the desired speed increases as does fuel burn. The deadweight of LCS is quire low for a ship of this size and volume and this reflects the performance. Bury it too deep and it operations will be severly curtailed.


Why is this important ....... well if runs to the adaptability provided by mission modules and weapons packages............. any weight you add in changing the design (up gunning) comes off the deadweight. Hence the comment about GP frigates.


I sense you have not read the books in question.

With all due respect, you don't sound very convincing to me. Your theory is based on old principle. You haven't given me information to believe what you're saying. Give me something concrete then I will analyze your information. You can read all the books you want but still those are all based on legacy designs. Be forward thinking and come to the 21st century.

 

[Abraham Gubler]

Be forward thinking and come to the 21st century.

The 21st century doesn't change physics. Trimarans and lightweight materials is nothing new. Just ask any Polynesian from 1,000 years ago. The nature of water displacement in the ocean hasn't been affected by anything in this world since the end of the last ice age.

 

[db2646]

The 21st century doesn't change physics. Trimarans and lightweight materials is nothing new. Just ask any Polynesian from 1,000 years ago. The nature of water displacement in the ocean hasn't been affected by anything in this world since the end of the last ice age.

I will not say anything more unless you can convince me otherwise. Humming Drone's comments and illustration is all that make any sense to me. If you can dispute what he said in his post then that would be something else. The only similarity of the Independence to Commercial vessels is the trimaran hulls (basically outside configuration). Other than that, the Independence in my opinion, is a break through in warship design. I wouldn't be surprised if the USN will go predominantly with the Independence's design for future LCS ships.

 

[Bonza]

With all due respect, you don't sound very convincing to me. Your theory is based on old principle. You haven't given me information to believe what you're saying. Give me something concrete then I will analyze your information. You can read all the books you want but still those are all based on legacy designs. Be forward thinking and come to the 21st century.

Oh, stop being so god damn condescending. People are taking time to answer your repeated questions and all you can do is reiterate over and over again that they're wrong and you're right, demanding concrete information from them and offering none to support your own point of view.

If you want to stay on this forum you'll alter your approach and do so quickly, because patience for your current posting style is rapidly running out. Say what you like about me, but don't insult the intelligence of the posters responding to you with this crap. And tacking "with all due respect" on to the start of your post doesn't make it any less insulting.

Consider this an official warning.

 

[db2646]

Oh, stop being so god damn condescending. People are taking time to answer your repeated questions and all you can do is reiterate over and over again that they're wrong and you're right, demanding concrete information from them and offering none to support your own point of view.

If you want to stay on this forum you'll alter your approach and do so quickly, because patience for your current posting style is rapidly running out. Say what you like about me, but don't insult the intelligence of the posters responding to you with this crap. And tacking "with all due respect" on to the start of your post doesn't make it any less insulting.

Consider this an official warning.

I understand that you are an Super Moderator. Do you think that I'm NOT being insulted when they tell me to read books and asks me to ask Polynesians from 1000 years ago? How do you think I feel? Is it possible for me to ask any Polynesian that were probably dead 900 years ago? I was not asking questions but rather expressing my opinions. Is it because these posters are identified as Defense Professionals that they're given the benefit of the doubt and have been here longer than myself? I could possibly give you my credentials and also be identified as Defense Professional. Just tell me what documentation you want me to submit. Thank you.

 

[RobWilliams]

You're sitting there openly admitting that you're an amateur in this sector, and when people who actually know what they're talking about take the time to actually give you the relevant information, to just sit back and say "Well you don't sound convincing" is unbelievable.

Believe it or not, some people here know more than you do. Instead of bumping chests with them about "not sounding credible" and all this BS then why not get involved in constructive chatter rather than 'I can't make any sense of this, so i'm going to disregard it completely'

Seriously, i'm not even involved in this debate and it's just been a complete and utter ball ache just reading through it.

Please, please PLEASE try to understand what they're saying rather than just throwing it away because you don't get it