BoatBanter.com

BoatBanter.com (https://www.boatbanter.com/)
-   Cruising (https://www.boatbanter.com/cruising/)
-   -   Using gyroscope on cruising cat to prevent capsize ! (https://www.boatbanter.com/cruising/65596-using-gyroscope-cruising-cat-prevent-capsize.html)

[email protected] January 23rd 06 11:34 AM

Using gyroscope on cruising cat to prevent capsize !
 

Has anyone tried installing a gyroscope in the form of a water-filled
disc under the bridge deck of a catamaran to reduce the possibility
of a capsize ?

Having a large wave hitting a catamaran is like lifting up one end of
the boat while letting the other end drop until the weight of the mast
and the bridge deck cause it to capsize.

However, a heavy gyroscope spinning at a very high speed under
the bridge deck can cause the boat to defy gravity and stay upright
with a large portion of it hanging in the air until the wave has passed.

And when the storm is over we can just let the water out of the disc
to reduce the weight.


News f2s January 23rd 06 12:10 PM

Using gyroscope on cruising cat to prevent capsize !
 

wrote in message
...

Has anyone tried installing a gyroscope in the form of a
water-filled
disc under the bridge deck of a catamaran to reduce the
possibility
of a capsize ?

Having a large wave hitting a catamaran is like lifting up one
end of
the boat while letting the other end drop until the weight of
the mast
and the bridge deck cause it to capsize.

However, a heavy gyroscope spinning at a very high speed under
the bridge deck can cause the boat to defy gravity and stay
upright
with a large portion of it hanging in the air until the wave has
passed.

And when the storm is over we can just let the water out of the
disc
to reduce the weight.


Don't forget precession. Put a lateral force in, and the gyro will
react by pitching.

JimB



Jeff January 23rd 06 01:16 PM

Using gyroscope on cruising cat to prevent capsize !
 
Its unlikely anyone would bother since catamarans don't actually
capsize as you imply. In fact, I've never heard of a capsize while
under bare poles; every instance is while under sail, usually far too
much sail. In other words, if you are at the point where you might be
dealing with a gyro, you've probably already done the necessary things
to ensure survival.

BTW, I learned celestial navigation while working on a craft that used
gyros for stabilization. When the gyros failed, the craft was scuttled!



wrote:
Has anyone tried installing a gyroscope in the form of a water-filled
disc under the bridge deck of a catamaran to reduce the possibility
of a capsize ?

Having a large wave hitting a catamaran is like lifting up one end of
the boat while letting the other end drop until the weight of the mast
and the bridge deck cause it to capsize.

However, a heavy gyroscope spinning at a very high speed under
the bridge deck can cause the boat to defy gravity and stay upright
with a large portion of it hanging in the air until the wave has passed.

And when the storm is over we can just let the water out of the disc
to reduce the weight.


News f2s January 25th 06 10:48 AM

Using gyroscope on cruising cat to prevent capsize !
 

"Jeff" wrote in message
...

BTW, I learned celestial navigation while working on a craft
that used gyros for stabilization. When the gyros failed, the
craft was scuttled!


Did it use the gyros to hold the craft rigid? or did it use them
to drive stabiliser vanes to counter roll?

JimB



Jeff January 25th 06 01:23 PM

Using gyroscope on cruising cat to prevent capsize !
 
News f2s wrote:
"Jeff" wrote in message
...

BTW, I learned celestial navigation while working on a craft
that used gyros for stabilization. When the gyros failed, the
craft was scuttled!



Did it use the gyros to hold the craft rigid? or did it use them
to drive stabiliser vanes to counter roll?


The gyros were used directly to keep the craft at the correct
attitude. There were six onboard when launched, and they failed one
by one. When they all died, it was abandoned and scuttled. BTW, the
cost of the craft was $250,000,000, 28 years ago.



News f2s January 25th 06 06:37 PM

Using gyroscope on cruising cat to prevent capsize !
 

"Jeff" wrote in message
...
News f2s wrote:
"Jeff" wrote in message
...

BTW, I learned celestial navigation while working on a craft
that used gyros for stabilization. When the gyros failed, the
craft was scuttled!



Did it use the gyros to hold the craft rigid? or did it use
them to drive stabiliser vanes to counter roll?


The gyros were used directly to keep the craft at the correct
attitude. There were six onboard when launched, and they failed
one by one. When they all died, it was abandoned and scuttled.
BTW, the cost of the craft was $250,000,000, 28 years ago.


I guess they had to use an even number, half rotating one way, and
half rotating the other, to cancel precession. What a project!

JimB



Jeff January 25th 06 08:58 PM

Using gyroscope on cruising cat to prevent capsize !
 
News f2s wrote:
"Jeff" wrote in message
...

News f2s wrote:

"Jeff" wrote in message
...


BTW, I learned celestial navigation while working on a craft
that used gyros for stabilization. When the gyros failed, the
craft was scuttled!


Did it use the gyros to hold the craft rigid? or did it use
them to drive stabiliser vanes to counter roll?


The gyros were used directly to keep the craft at the correct
attitude. There were six onboard when launched, and they failed
one by one. When they all died, it was abandoned and scuttled.
BTW, the cost of the craft was $250,000,000, 28 years ago.



I guess they had to use an even number, half rotating one way, and
half rotating the other, to cancel precession. What a project!


The "craft" was the Einstein Observatory, and orbiting x-ray
telescope. The gyros are called CMG's, control moment gyros -

"a gyroscope, usually much larger than a gyro sensor, mounted on a
single or double gimbal and used to generate control torques. The
torques are generated by commanding gimbal angle rates that result in
inertial motion of the CMG spinning wheel and accompanying gyroscopic
reaction torques on the vehicle structure."

IIRC, they decided to save a few mil by not including magnetic torque
rods, which would torque against the Earth's magnetic field to
maintain stability.

Sailing content: The previous x-ray telescope was placed in a lower
orbit, and as the orbit decayed it started bouncing against the
atmosphere. The controllers (clever MIT grad students) oriented the
solar panels so it would surf on the atmosphere, and extended its
useful life by several months. OK, its more like water skiing than
sailing.

News f2s January 25th 06 09:18 PM

Using gyroscope on cruising cat to prevent capsize !
 

"Jeff" wrote in message
...

The "craft" was the Einstein Observatory, and orbiting x-ray
telescope. The gyros are called CMG's, control moment gyros -

"a gyroscope, usually much larger than a gyro sensor, mounted on
a single or double gimbal and used to generate control torques.
The torques are generated by commanding gimbal angle rates that
result in inertial motion of the CMG spinning wheel and
accompanying gyroscopic reaction torques on the vehicle
structure."


Ooops!

Interesting people we meet round here. Understood completely.

My previous history was aeronautical systems - in the wider
sense - many moons ago.

JimB




All times are GMT +1. The time now is 06:39 AM.

Powered by vBulletin® Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
Copyright ©2004 - 2014 BoatBanter.com