RE: [PSUBS-MAILIST] Stiffener question

[Alec Smyth <Asmyth@changepoint.com>]

Uhmmm... on second thought there is one sentence I don't get. "The Length of
the hole is clear greater as the length of the rest frame between them,
about 40/60 I think."

Let me describe what I'm talking about in very scientific terms. Imagine the
stiffener is made of cheese and has a height of 3 cm. A large mouse comes
along. The mouse's mouth is about 2 cm wide, and semi-circular. The mouse
takes a bite off the edge.  

If the result is one of your "long-holes", then it would have a diameter of
2 cm. But because its a semi-circle, it would reach only 1 cm towards the
center of the stiffener. So if I understood your description, the cheese
might still be classifiable since 1 cm is a third of the frame depth.

Now to the sentence above that I didn't understand; are you referring to the
distance between successive bites if the mouse rotates the cheese and bites
off another bit?

thanks,

- Alec

-----Original Message-----
From: MerlinSub@t-online.de [mailto:MerlinSub@t-online.de]
Sent: Monday, August 20, 2001 12:43 PM
To: personal_submersibles@psubs.org
Subject: Re: [PSUBS-MAILIST] Stiffener question


Hi Alec - semicircular nicks  means lonh-holes right ? 
I look to my rules book - and surprice - no description - 
only the term "has to be calculate". 

But than I look to the internal pictures of the Seahorse Offshore
sub - a Boat with classefication. The long-holes have about 30
Percent of the stiffteners high. The Length of the hole is clear greater 
as the length of the rest frame between them, about 40/60 I think. 

The problem is that the welding frame/shell has to be of the close type 
- means has to go inside the longhole to the other side - this indicate 
that the hole must have a size so you can work with the stick or pistol. 
Indicate a hole high of at least 1 inch minimum - and thats indicates
a frame high of about 3 inch at least. 

Maybe on smaller frames it is better to drill holes in the stiffteners 
quite near the shell and before you weld them into the shell. 
The distance "near the shell" means there should still stay of about 
a half inch of the stiffteners - so you can make easy a close weld. 

Hope the language was not to funny.. 
Carsten


> Alec Smyth schrieb:
> 
> SOMEWHERE I once read you could machine semicircular nicks on
> the external radius of internal stiffener rings. These are useful for
> running longitudinal wires or piping while keeping things protected. I
> think the allowable radius of these semicircles was expressed in terms
> of the of the stiffener diameter.
> 
> Problem is, I can't find where I read this. Does anyone have this
> info, or at least some rule of thumb?
> 
> thanks!
> 
> - Alec
> 
>