Re: [PSUBS-MAILIST] Flat Acrylic windows and GermanischerLloyd Rules

["Andy Jensen" <drewacard@charter.net>]

Carsten
Thank You! 
   I understand now.

Andy J

On Sun, 28 Jul 2002 13:12:12 +0200
  MerlinSub@t-online.de (Carsten Standfuss) wrote:
>Hi Andy, 
>
>Andy Jensen schrieb:
>> 
>> Germanischer Lloyd Rules for Underwater Technology
>> Section III - Part 1    Appendix B Acrylic Plastic 
>>Windows
>> I am trying to figure out the safty margen for the Table 
>>2
>> 
>> This is what I was thinking flat window
>> Di 10” ,254mm internal dia
>> Do 12” ,381mmexternal dia
>> S 4.5” ,114.3 thick
>> S/Di = .45
>> On the table
>> @ 24°C,75°F
>> 170 bar 2400psi 5400fsw
>> test depth =3500
>> “safe”depth=1700
>> 
>seems right.. (but s/di is 0,456 not 0,45.. get 116 mmm)
>but 24 degree at 1700 m deep.. (5600feet)
>- you want to visit vulcanos ? The temp.figure
>is to calculate with : Inside sub temp + outside sub temp 
>divided by two. Example : Inside 21 degree and outside 
>(at 5600.. ) 4 degree = 21 + 4 = 25/ 2 = 12,5 degree. 
>
>> all is well
>> then  as I am sifting through the archive I found.
>> 
>> "And CSSX will have two flat viewports diameter of 
>>700/600
>> with 110 mm thickness for 250 Meter (or 27,6 in /23,6 in
>> with 4,3 in thickness for 820 feet) "Carsten
>> 
>> I ran the numbers and came up with an s/D .183 on the
>> table at 10°C,50°F   20 bar or 800 fsw
>> Is this the safe working depth? And the pop depth would
>> 2400fsw
>> 
>(hmm.. found 0.188 on the table..)
>
>Okay I run it with this new table (I use an old one for 
>the earlier
>calculation ) and get : 
>
>inside diameter : 600 mm
>temp degree 	: 10 celsius
>design pressure : 25 bar
>
>and get a s/di of 0,201 
>
>so S should be 0,201 x 600 mm = 120,6 mm (and not 110..)
>
>I don't know wich saftey margin they have but for the 
>pressure hullintsef they run in the area of two. 
>
>Carsten - but not any window in my vessel design now - 
>will use some
>high resulution video cameras and big TFT screens - is 
>much cheaper, 
>quicker to build, can see more, can tape it, can use 
>picture processing
>software to elimate dusty water. And of course maybe more 
>safe. 
>But makes sence only on bigger vessels. 
>
>> Could someone shed some light on this Please
>> 
>> Btw I down loaded the tables from
>> http://www.germanlloyd.org/infoServices/rules/pdfs/english/glrp-e.pdf
>> 
>> Andy J