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
uss enterprise 18/51 yos
uss Nimitz 14/45 yos
Roosevelt 12/26 yos
Forrestal class 1 deployment every 2.33 years
Kitty hawk class 1 deployment every 2.76 years
uss enterprise 1 deployment every 2.83
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
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.