[PSUBS-MAILIST] G.L. Summary Stability & Buoyancy

[brian]

It would be nice to see a schematic of this assembly or a picture since I'm not really grasping what is going on with the seal and bearing assembly.
Brian
-----Original Message-----
From: "hank pronk" <hanker_20032000 at yahoo.ca>
Sent 12/5/2013 11:12:31 AM
To: "Personal Submersibles General Discussion" <personal_submersibles at psubs.org>
Subject: Re: [PSUBS-MAILIST] G.L. Summary Stability & BuoyancyVance,Funny you mention the inner tube.  I did just that as an experiment on my red sphere sub.  I even painted the inner tube white so it would blend in better.  I took a big leap of faith this morning, I just finished machining the prop shaft bushing housing.  The housing has a bearing and seals now.  I drilled in two ports (1/8 pipe) to fill and drain the oil.  I like it much better and I have to drain the oil regularly in the second shaft housing anyways.  I also decided to buy a new motor instead of using the original.  I am driving to the USA tomorrow to pick it up.  That was my Christmas present. :-)    I am very easy to shop for
:-)Hank  On Thursday, December 5, 2013 10:47:14 AM, "vbra676539 at aol.com" <vbra676539 at aol.com> wrote:Which suggests a big inner tube if you want to convert a DW2000 to that definition. Otherwise, keep the door shut, or prepare to swim.Vance-----Original Message-----
From: Phil Nuytten <phil at philnuytten.com>
To: Personal Submersibles General Discussion <personal_submersibles at psubs.org>
Sent: Thu, Dec 5, 2013 11:11 am
Subject: Re: [PSUBS-MAILIST] G.L. Summary Stability & BuoyancyThe minimum hatch to waterline measure applies to those submersibles
‘intended to be entered while afloat’ - Phil From:Jon WallaceSent: Thursday, December 05, 2013 7:33 AMTo:Personal Submersibles General
DiscussionSubject: Re: [PSUBS-MAILIST] G.L. Summary Stability &
Buoyancy 
I think the first sentence is key, "Submersibles
will be assigned Class only after it has been demonstrated that their buoyancy
and their static and dynamic stability in in tact condition is adequate FOR THE
SERVICE INTENDED".  Some of the lack of specificity is because they can't
conceive of every possible application.  They do however have quite a few
specifics as you outlined.  Some of the testing won't apply (ie fuel load)
and it's possible that a narrow scope of service might lower number of tests
required.
On 12/5/2013 4:08 AM, Alan James wrote: I'm afraid there is
nothing simple in this section. It is lacking in a lot of specifics.There are statements
such as "shall generally meet the standard definedin the following
unless special operational restrictions reflected in the classnotification allow a
lower level. & ...Depending on the type of submersible & the operation area, the
distance between the waterline in fully surfaced conditionand the upper edge of
entrance openings, air pipes,etc. which may be openfor surfaced
operation, has to be approved by G.L.   ABS has
a minimum distance from the waterline to the hatch opening of 30"whereas G.L. states;
For surfaced; a
minimum distance between
metacentric height & center of gravity of 10cm. (4")
And for submerged, a
minimum distance between center of buoyancy & center
of gravity of 5cm (2")
(same as ABS). At no stage will G be above B. (including after dropping the
drop weight)In
the initial paper work sent before construction, a detailed analyses of
stability is tobe
included.  This
takes the form of analyzing the heeling levers of 10 different load cases in
fresh & salt water, 6 on the surface & 4
submerged & at 6 different heelingangles. So looks like
120 calculations. Heeling forces from
free liquid surfaces, turning circles, wind, ice loads, transference
of
equipment & personal & payloads from working devices have to be
considered.There needs to be
sufficient ballast to keep a minimum of 10% of the pressurehull out of the water.
The draught line has to be marked on the hull. When one major ballast
tank is damaged the hatch has to be able to open withoutwater coming in &
the heeling angle shouldn't exceed 22,5 degrees.There is an operational
in water test at the end of construction with evaluationof the center of
gravity upon which the pre build calculations were based.Alan   _______________________________________________
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