Re: [PSUBS-MAILIST] hull test

[Ian Roxborough <irox@ix.netcom.com>]

Hi Bill,

I'm not familar with the microwave based underwater communications
equipment you're refering to.  Do you have any pointers or links
you could read up on this?

It has been my understanding that radio waves don't travel very far
underwater.  The water absorbs the energy from the microwaves within
a few wave lengths, which wouldn't be very far given the short wave
length of microwaves.

Somebody else on this list a while back claimed that it is possible
for underwater radio wave transmission as a communication method.
If I remember correctly they where building something based around
this method.

Cheers,
 Ian.

On Wed, 26 Oct 2005 13:29:46 -0400
"Akins" <lakins1@tampabay.rr.com> wrote:

> Your below post got me to wondering Dan.
> 
> Since we use microwave transmissions for underwater communications,
> why couldn't microwave transmissions be used to activate a remote
> control in a sub the size of Carsten's so that a test line would
> only be there for making sure the sub did not drift away and for a
> secondary backup. Would the microwave transmissions go thru the hull and
> the remote could be rigged to activate the ballast pumps so the sub
> could surface after the test depth and time were reached?
> 
> Would this be feasible or practical?
> 
> Bill.
> 
> 
>   ----- Original Message ----- 
>   From: Dan H. 
>   To: personal_submersibles@psubs.org 
>   Sent: Wednesday, October 26, 2005 8:12 AM
>   Subject: Re: [PSUBS-MAILIST] hull test
> 
> 
>   Silky,
> 
>   A sub hull is a lot of money and work to loose if you lower it to the bottom 
>   for a test on a line, with no person in it, but it's the safest way to test 
>   a personal sub.  Of course testing in a pressure chamber would be even 
>   better but most small sub builders don't have or can't afford this luxury. 
>   Even with the risk of loosing the sub because of a simple line malfunction, 
>   a deep water test of the hull should be done unmanned.  After all, it's a 
>   test to see if you'll be safe diving in it.
> 
>   A sub the size of Carsten's is not in this category.  I can only imagine the 
>   feeling in Carstan's gut when he does his tests, manning it himself.  I have 
>   a lot of faith is the calculating skills of a man that can design and build 
>   such a project and I'm sure he's pretty confident he will have no problems 
>   he can't solve as he goes, but we all know there is considerable risk 
>   involved.
> 
>   P-subs should only be test proven unmanned!
>   Dan H.
>   ----- Original Message ----- 
> 



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