[PSUBS-MAILIST] Main Ballast Vent "T".

Fri Jul 31 17:49:53 EDT 2015

So James, How do  you get the air to run downhill to your vent which is now underwater.  As the guys explained the top part of the vent if it is full of water will not vent.

Your drawing shows the problem. Vent point must be above bubble.  You cant dive at an angle like U-boats. The problem is not the lip. Hugh

From: Personal_Submersibles [mailto:personal_submersibles-bounces at psubs.org] On Behalf Of James Frankland via Personal_Submersibles
Sent: Friday, 31 July 2015 8:55 p.m.
To: Personal Submersibles General Discussion
Subject: Re: [PSUBS-MAILIST] Main Ballast Vent "T".

Hi Alec,

I think its because I made my tanks slightly different.  They are not the same as proper Kittredge ones.  I have a feeling that there are two issues.  The profile of the tank is not as steep as Kittredge ones.  Well, they don't look it to me, I haven't got any proper K tanks to reference against.   So I think its more prone to getting stuck.  

The other issue is that I have quite a large lip on the inside which is to help eliminate burping for use in the sea.  However, I think this prevents the escape of air.  I think that maybe the standard K boat tanks would spill the bubble out the end of the tank if you dived nose or tail first, whereas the lip on mine catches it.

Im hoping the new vent might cure the fault but I have a worry now.  I could end up with the same situation if the water blocks vent 1.   Im hoping it will relieve the bubble enough for the boat to start to level and allow final venting from the proper vent.  Will have to see if it works.....  See terrible picture.  Im at work, and I did this in MS paint...

Pic shows potential problem...

Regards

James

On 30 July 2015 at 22:16, Alec Smyth via Personal_Submersibles <personal_submersibles at psubs.org> wrote:

This is interesting because the K350 and K250 have virtually the same design in this respect, but I can't induce this problem even on purpose. If I flood one tank 100% and only then start flooding the other, so that the boat feels like she's standing on her head, I still don't get a bubble block. Well... no complaints! But I'm looking at it carefully because I'm following the K design on the new boat as its worked well for me.

Best,

Alec  

On Thu, Jul 30, 2015 at 4:44 PM, Hugh Fulton via Personal_Submersibles <personal_submersibles at psubs.org> wrote:

Hi James,

I had a similar problem with the Comsub.  When it gets a bubble the vent is in the wrong place.  Centralised venting can create problems.  I am going localized pilot operated venting.

Regards,  Hugh

From: Personal_Submersibles [mailto:personal_submersibles-bounces at psubs.org] On Behalf Of James Frankland via Personal_Submersibles
Sent: Thursday, 30 July 2015 8:46 p.m.
To: Personal Submersibles General Discussion
Subject: Re: [PSUBS-MAILIST] Main Ballast Vent "T".

Hi Hugh,  Drawing is not to scale or anything, it was just to give you an idea.  Anyway, its going in this weekend.  I know where the bubble is.  I think maybe my tanks are not as steep a profile as original Kittredge ones.  Maybe that's why I get the bubble.  Anyway, im pretty sure this will cure the issue.

Regards

James

On 29 July 2015 at 21:58, Hugh Fulton via Personal_Submersibles <personal_submersibles at psubs.org> wrote:

Hi James.

Turn your drawing at the angle you think you want, draw a line horizontal, then see if the outlet is above the bubble.

Hugh.

From: Personal_Submersibles [mailto:personal_submersibles-bounces at psubs.org] On Behalf Of James Frankland via Personal_Submersibles
Sent: Thursday, 30 July 2015 1:11 a.m.
To: Personal Submersibles General Discussion
Subject: [PSUBS-MAILIST] Main Ballast Vent "T".

Hi All,

Im going to T in another vent pipe into my main ballast tank at the back.  Unless I submerge perfectly straight, I get a bubble stuck in either the front or rear tank. 

If I T in this vent extension to the existing line, I can dive nose first and still get the bubble out.  I cant see anything wrong with this, but I though id ask in case anyone has any thoughts?  
Thanks

James

_______________________________________________
Personal_Submersibles mailing list
Personal_Submersibles at psubs.org
http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles

_______________________________________________
Personal_Submersibles mailing list
Personal_Submersibles at psubs.org
http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles

_______________________________________________
Personal_Submersibles mailing list
Personal_Submersibles at psubs.org
http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.whoweb.com/pipermail/personal_submersibles/attachments/20150801/e2a11e28/attachment-0001.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image002.jpg
Type: image/jpeg
Size: 22184 bytes
Desc: not available
URL: <http://www.whoweb.com/pipermail/personal_submersibles/attachments/20150801/e2a11e28/attachment-0002.jpg>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image003.jpg
Type: image/jpeg
Size: 12559 bytes
Desc: not available
URL: <http://www.whoweb.com/pipermail/personal_submersibles/attachments/20150801/e2a11e28/attachment-0003.jpg>