Re: [PSUBS-MAILIST] Another response from Hunley archaeologist.

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

Hi Bill,

I think technically it's 1ATM submarine, not a hybrid, not ambient.
It's a 1ATM submarine with a slight higher than 14.7psi internal pressure.
I don't see any other way of looking at it, it's a 1ATM that works like
a 1ATM.  The slight increase in pressure does not effect how the submarine
works.

If it is a hybrid, how does it work?

Some other examples:
  - somebody farts in a submarine and increases the internal pressure,
    does that automatically stop being a 1ATM and become some sort of
    hybrid?

  - A new life support system that let's out a little too much O2
    causing a slight pressurization of the cabin.  It's still 1ATM
    and still worts like a 1ATM.

  - Some military subs vent certain tanks into the pressure vessel
    causing a higher internal pressure, but this doesn't changes
    anything about the sub that stops it from being 1ATM.  (Can't
    remember which tanks or which subs, but I remember hearing older
    submariners complaining of ear poping when they vented certain
    tanks.)

I've sure there are others as well (so I could be wrong with
some of the above), but a minor increase in pressure in 1ATM
doesn't stop the boat from being a 1ATM, nor does it add any
features of an ambient.

Cheers,
  Ian.

On Fri, 10 Jun 2005 00:41:57 -0400
"Akins" <lakins1@tampabay.rr.com> wrote:

> You raise  valid points Ian. But if the Hunley was not ambient, she could not technically be 1 atmosphere either, since any compression of her atmosphere over 1 atmosphere of pressure would technically make her not 1 atmosphere.
> 
> I am starting to wonder if the Hunley is actually neither, but a hybrid of both, not falling technically into either catagory but having attributes of both. Something I have never seen before.
> 
> I received another e mail from the Hunley archaeologist Michael P. Scafuri as a follow up to his first e mail. In it he said that they are not really sure how the Hunley worked yet, and that further investigation may prove that she was
> 
> slightly buoyant and did have to use her forward motion and dive planes to submerge like the later Holland did. This somewhat contradicted his first e mail and further confuses the issue.
> 
> I wrote him back again asking for a definite answer as to whether the Hunley was ambient, not ambient, or some kind of hybrid. I also mentioned we would love to know if she was always slightly positive buoyant as soon as he
> 
> and the conservatory can determine that. So bottom line here is the best information we have coming from the archaeology experts is that they are not sure of a lot of things yet. I'm trying to find out for us all, but we may have to wait
> 
> for more investigation by them, or we may actually not ever know. Here's our latest correspondence below. The first below one  is my response to his original e mail, the second one his lastest and second e mail to me, and the third one my latest e mail
> 
> to him that I am waiting for a reply from him on. I'll post his reply here as soon as I receive it. The mystery of the Hunley goes on.
> 
> Kindest regards,
> 
> Bill Akins.
> 
> 
> ----- Original Message ----- 
> From: Akins 
> To: Michael Scafuri 
> Sent: Thursday, June 09, 2005 3:05 PM
> Subject: Re: H.L. Hunley
> 
> 
> Thank you very much Mr. Scafuri.
> 
> I posted your reply to the PSUBS.ORG forum where we have been discussing the Hunley a lot. I know they will be glad to hear from you.
> 
> I had thought that the Hunley was always slightly positively buoyant like the later Holland submarine was and that she had to use her dive planes to 
> 
> force her under like the Holland did. From your reply it seems the Hunley was technically ambient but not always slightly positive buoyant.
> 
> Thanks again for your reply clearing these questions for me.
> 
> Kindest regards,
> 
> Bill Akins.
> 
> ----- Original Message ----- 
> From: Michael Scafuri 
> To: Akins 
> Sent: Thursday, June 09, 2005 3:55 PM
> Subject: Re: H.L. Hunley
> 
> 
> I am glad to help.  Please keep in mind though that, at this point,  we don't really know how the Hunley performed, how seaworthy she was, exactly where her waterline was, etc.  It is still speculation for the most part - educated speculation but speculation nonetheless.   We might find out one day that yes, she did in fact need her dive planes to submerge; I don't think so, but with such a unique vessel almost anything could ultimately be true.  The Hunley has surprised us before.
> Take care,
> 
> Mike Scafuri
> 
> 
> 
> 
> Hi Mr. Scafuri.
> 
> Thanks again for your help and explainations. 
> 
> I take from your most recent e mail that it is actually unclear if the Hunley was always slightly positive buoyant like the Holland submarine was. As you said you may find that the Hunley was only able to submerge by using her forward motion and dive 
> 
> planes to keep her under just like the Holland submarine. I understand it will take a lot of time and research to acertain exactly how she really worked.
> 
> One thing I hope you could clear up for me is whether the Hunley was technically ambient or not. Was she ambient because her atmosphere was slightly compressed due to the ballast tanks
> 
> being open to the hull interior? Or was she NOT ambient because of what my fellow Psub.org member says here....."I still don't see any reason that the Hunley is ambient.  If it was ambient it couldn't
> 
> dive without pressure compensation, this does not appear to the the case. Unless some piece of information is missing, the Hunley is 1ATM.  The crew were always subjected to surface pressure (give or take the very small amount of
> 
> pressure increase from the ballast tanks venting into the cabin).  Once submerged, it doesn't matter what depth the Hunley is at, the crew will be under the same pressure, if it was ambient, the pressure the crew would be experiencing would
> 
> be the same as the external water pressure. If somebody can supply me the internal volume of the Hunley and the volume of water used to dive, I will calculate the internal pressure after diving."
> 
> So Mike, could you please clear up for us whether the Hunley was technically ambient or not? Was she some kind of a hybrid that was neither totally ambient nor totally 1 atmosphere?
> 
> If that is the case then how do we catagorize what the Hunley was? 
> 
> I would also like to know if she was always slightly positive buoyant (like the Holland) when that can be acertained finally by you and the conservatory. 
> 
> We have been discussing the Hunley ongoing for a long time at our Psubs.org forum, and it would be nice to know how she really worked.
> 
> Thanks again for taking the time to get back with me.
> 
> Kindest regards,
> 
> Bill Akins. 
> 
> 
> 
> 
> 



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