Building Warships or Peaceships?

Are we biulding warships to win a war or to win a peace?

The question came up when I was reading the design notes on our Armidale class patrol boats.

In them it was noted that the decision was made not to biuld them to the standards of warship, effectivily making them armed merchant vessels maybe.

This is fine as patrol boats are of limited value in a hot war, except we are now getting reports that engine mounts are cracking etc, which is a direct result of operating in too high a sea state or too long a max rated sea state.

It got me wondering about the larger types of warships out there.

Back in 2003 or 2004 I was suprised to see what I thought was a strip of armor plate running down the side of the old ffg HMAS Adeliade when she visited Adeliade. It did not take me long to realize that in fact it was a hull stiffing brace. It was not until I had a chance to look at her sister ship the Newcastle to see that the bracing was not present.

The only conclusion I could draw was as the Australian built HMAS Newcastle was constructed from local  steel plate that was thicker and less prone to damage than her Amercian bulit sisters. here are the two photos proving the point. note the two braces just below the mains sea deck on the Adeliade which are not present on the Newcastle.

HMAS Adeliade
HMAS Newcastle note no bracing.

Iam currently looking at the USA's supercarriers seeing if there is signs of hull stress in their history. Been current ships they are subject to security issues which makes the study of their hull design problematic to say the least. With no hard data to go on you have to troll through what is available. As to the been a problem the fact that they changed steel type to a much stronger type which has resulted in a increased availability of the Newer ships. Here are the availabilty figures for the super carriers.

 Carrier time line

  Name                      number of deployments on average

 Midway class                 no data available                      

 Forrestal class           21 /49yos

  Kittyhawkclass          21/58yos                                                                                                            

 uss enterprise           18/51 yos

 uss Nimitz                  14/45 yos

 USS Theodore Roosevelt   12/26 yos

 availability rate

 Forrestal class  1 deployment every 2.33  years

 Kitty hawk class 1 deployment every 2.76 years

 uss enterprise 1 deployment every 2.83 years

 uss Nimitz 1 deployment every 3.21 years

uss Theodore Roosevelt  1 deployment every 2.166 years.

USS john stennis 1 deployment every 1.58 years.

 Average time between major overhaul 2-5 years depending on damage while in service

 The midway class was created especially to be the first American   armored carrier and as a ship the size of a heavily armored  Essex class would have been useless as an offensive weapon due to the lack of aircraft numbers. To overcome this problem the midway design was increased in size to ‘float’ the required armor. Interestingly the hull design was based on the defunct uss Montana hull so continuing the successful idea of basing large armored carrier designs on existing cruiser designs or battle cruisers / battleship designs  which  shows  there were more than coincidence that the size of current us carriers were the same end result that battleship designs were heading before their demise.

 Another observation to be made is that the midway class was a very ‘wet’ ship throughout her life which goes somewhat to answering  what sort of ‘sea boat’ the Montana class would have been; and before you go and say that this observation is ‘long bow to draw’ the Montana would have sat lower in the water any way and the lineage of the midway’s hull is clear to see in early photos.

 All the carriers are prone to fire accident that can take many hours to put out. Contrary to reported safety practice of evacuating jp-5 refueling lines when no refueling activity  and filling empty pipes with inert gas ( a safety procedure reported  to be in place since Essex class). One fire in USS Constellation in 1988 reported to be started by jp-5 pipe leak just as ship cleared harbor.

 Far as I know flight ops do not occur in or near harbor except for landing air wing maybe?

 All ships seem o be maintenance intensive and need regular periodic maintenance of varied complexity ranging from 6 to 18 months.

 Nuclear carriers seem to be capable of lesser number of deployments over their life span than the oil fired carrier in spite of 20 year refueling cycles. 18 to 21. The conclusion here is that the older ships had stronger hulls.

Decision timeline  offensive ability over survivability 1954  removal of armor belt midway class armored deck retained

 Availability for deployment has kept dropping until the  USS Theodore Roosevelt was commissioned .probably due to the modular construction of her hull The USS john stennis is further improved by the use of las 100 steel been used ,the same standard used in sub construction in her 19 years of service she as racked up 12 deployments . A availability ratio of 1 deployment for every  1.58 years. Makes you wonder if the hulls of the earlier ships suffer a higher attrition rates due to the use of leaker construction steel?. This brings into question the damage control factor of these ships to absorb damage and maintain an operational ability. I.e. resistance to shock and tarrying bending moments etc.

 The conclusion can be drawn that fiscal policy decessions can be just as damaging to the design of warship as any naval treaty. Another factor here could be the increased availablity could be as a result of operational requirments only due to the war on terror being conducted at this time. If this is the case that operation tempo/requirements are being put ahead of standard maitance requirments, this will plan out with a shorter overall hull life and early retirment of the vessels in question.

We will have to wait and see.  

US Carrier Internal Layout Slip up?

As stated I have speculated on the Internal layout of USA's post war Carriers. The last ship design publically released is the USS Midway. As you can pay to see over this Carrier it is understandable that secrecy is moot.

This is probably why no other 'Super Carrier' will ever be placed on public display in the USA.

The photos below is what I consider a slip up by US censors and shows marking on the deck of CVN-65 that seems to indicate the reactor locations which locations suggest that the following 'Super Carrier" classes after CV-41, used VERY similar layouts to that of CV-41 which based it engines, generator rooms and fire(boiler) rooms in a central corridor either side of the centre line down the central centre of the hull. 

What do you think?

 

Fig 3. lower platform deck layout of CV-41. Engine rooms are high lighted. Inner prop engines are forward of the two outer props.
fig 4. Suggests that the reactors and engines are similarly placed either side of the centre line and spread out over the length of the hull in a similar layout. Mind you it is not possible too guess accurately which indicates too which shaft is been driven. the turbines have to be near by. Also the shafts come out with a wide lateral spacing according to display models which in itself supports the proposed reactor positions. My best guess actually indicates a reversal of the CV-41, the rear most are the inner props shafts and the fore are the outer shafts. This would be supported by the various displayed models that show the outer shafts exiting the hull well forward of the inner shafts and with a wide lateral position in relation to the inner shafts.
fig 5. This shows the position with more accuracy. Note closer relationship with rear two markings. I seem to remember reading somewhere that it good to have the shaft loads balanced or equal to remove vibrations and requirements for different blade count on propellers. I.E. Iowa class battleships etc. There is also some damage control sense here as that is one problem WW2 4-shaft warships had that both shafts on one side were most likely be taken out by one torpedo hit.

Photo Opps moments?

still shot that ties the individual hull pieces together. shows reactor position and complete torpedo protection/ tank layout. Clearer if you watch video link supplied.

The US navy goes to a lot of trouble trying to not give away the actual internal hull arrangement of it's super carriers and yet the following images are out there. 

From which you can make more than just some educated guesses once you realise that they are designs that generally follow on from previous classes. 

fig 6. One possible layout
31 sec into time lapse video. excuses free hand highlighting.

Latest comments

19.05 | 15:01

Good point! I was thinking Helo pads but never got around to it. The design thought been why not have full port or base resources including dry dock and repair

19.05 | 11:44

Why is there no airport on top of the base?

03.04 | 13:07

Just found your site-very cool. Also agree with your views regarding government decision processes, all about looking after their arse after they're booted out

19.01 | 08:39

Detailed answers on blog page.