[C320-list] Engineers - was - Leak in bilge

[Utility Email]

Touché. 



On Jan 23, 2011, at 5:28 AM, Chris Burti <clburti at gmail.com> wrote:

> I can't resist sharing an observartion I once read or heard about Engineers.
> 
> An Optimist says that the Glass is half full;
> 
> The Pessimist says that it is half empty...
> 
> The Engineer states that it is the wrong size.
> 
> 
> 
> 
> On Sun, Jan 23, 2011 at 1:36 AM, Utility Email <kswanson123 at comcast.net> wrote:
>> Bruce
>> 
>> The Society of Women Engineers (SWE) website reference is great.  I have one of their engineering dictionaries that gets a lot of use by the younger engineers in my design office (bought it in college 25 years ago, out of print now).  Thanks for their website reference, there is a lot of good stuff there that I didn't know about!  Thanks.
>> 
>> Dave
>> 
>> 
>> 
>> On Jan 22, 2011, at 6:05 PM, "Bruce Heyman" <bruceheyman at cox.net> wrote:
>> 
>>> David,
>>> Thanks for commenting!  The reason I brought up Archimedes is because he is
>>> widely credited for figuring out simple machines and as far as I'm concerned
>>> a bolt and nut are a simple machine.  The threads form the incline plane.
>>> http://www.swe.org/iac/lp/inclined_03.html
>>> Best,
>>> Bruce
>>> Somerset #671 SoCal
>>> 
>>> -----Original Message-----
>>> From: c320-list-bounces at lists.catalina320.com
>>> [mailto:c320-list-bounces at lists.catalina320.com] On Behalf Of Utility Email
>>> Sent: Friday, January 21, 2011 11:09 PM
>>> To: C320-List at Catalina320.com
>>> Cc: <C320-List at Catalina320.com>
>>> Subject: Re: [C320-list] Leak in bilge
>>> 
>>> Well, I'm a structural engineer.  After reading this post, I was confused
>>> too.  Here are some clarifying remarks by an SE.
>>> 
>>> 1.) If you draw a free body diagram, you will see that the keel bolts do in
>>> fact hold up the keel.  The connection between the keel bolt nut and the top
>>> of the keel will in fact stretch these large SS bolts as it compresses the
>>> hull in this area.
>>> 
>>> 2.) I would agree with this statement, but adding one important item that
>>> these bolts do in fact support the keel.
>>> 
>>> 3.) True that a threaded bolt and threaded nut transfer rotary gorge into
>>> vertical movement along the axis of the bolt to hold two surfaces together.
>>> It is not clear to me what the rest f the statement is getting at,
>>> especially the remark about Archimedes who ave us th principal of buoyancy.
>>> 
>>> 4.) A torque wrench is typically calibrated to take into account the
>>> friction between the nut and the threads in the, so called, "machine.". The
>>> torque in the wrench is calibrated to relate to the axial load (or
>>> pretension) in the bolt.
>>> 
>>> 5.). I'm not sure if this is correct.  Preload is not related to material
>>> strength.  Machine design tables would provide this information.  Preloaded
>> 
> 
> 
> 
> -- 
> Chris Burti
> Farmville, NC