Re: [PSUBS-MAILIST] kitredge sub

[VBra676539@aol.com]

In a message dated 10/12/2003 12:22:20 PM Eastern Daylight Time, 
2stroke@hetnet.nl writes:

<< I agree with you. Altough an Aluminium sub can go deeper than a steel one, 
it has a lot of disadvantages. So are the high grades not weldable, it has a 
bad resistance to seawater, more difficult to paint and its costs about 6 
times more than steel . Think composites are even more difficult to work with.
 Some years ago I read an newspaper aticle that a aluminium midgetsub from 
north Korea ran aground on a spying mission. >>

As Dan said, it depends on the design--and your assessment of aluminum in 
seawater is correct only part way--the lower grades of aluminum are very 
susceptible to corrosion, and yet the Johnson Sea Links (using 6000 series) have NEVER 
seen paint, and don't corrode. And for a comparison, the aft chamber of a JSL 
is over 3 inches thick in the cylindrical section, and is rated at 3000 feet. 
A Perry PC-16, made of HY-100 milspec steel is also rated at 3000 feet, but 
is only 1/2 inch thick. The 1000 meter Pisces subs are 1.1 inches thick, and 
built (usually) of A537 or something equivelant. It's all apples and oranges, 
and you have to figure out whether you like citrus before making the choice.
Vance