NavList:

   

Reply

Joe Schultz described fluxgate compasses as "First tried at the fleet level
in the first gas-turbined frigates (US Navy) at least 25 years ago."

To which I replied-
"I wonder: were those "first gas-turbined frigates" that Joe refers to,
built
of steel? If so, I'm interested in what, if anything, was in place as a
first-order correction for deviation, if these were, as Joe's words
"self-correcting" compasses. Did they have the familiar correction magnets,
and the hollow soft-iron spheres placed to port and starboard of the compass
housing? I would be surprised if any electronic correction algorithm, such
as we have been discussing, was capable of tackling the enormous deviations
that a steel vessel gives rise to, without some such first-order
corrections."

And Joe has responded-"Yes, George, US Navy ships are made of steel.  Very,
very special steel..."

==============

Well, it wasn't such a dumb question as that. Some Royal Navy vessels have
been designed with aluminium-alloy superstructure above a steel hull, (with
fatal consequences in the Falklands war). Which would reduce, though not
eliminate, the need for correction for induced magnetism.

And he added-
"The advantage of these "electronic" compasses is that you can put the
sensor assembly anywhere you want - no need for "Navigator's Balls."  Find
the sweet spot and put it there."

Tell us how well that works, please, Joe. I can see that a remote-reading
compass can be put at the top of a mast (with which warships bristle)  and
that could perhaps move it far enough away from hull-influence, so that
internal-correction might suffice. But can Joe's "sweet spot" be located
anywhere below (where accelerations will be less) in a steel hull and still
avoid the need for the iron balls? Joe seems to be speaking with some
authority on this topic, and I hope we can discover more.

George.

contact George Huxtable, at  george@hux.me.uk
or at +44 1865 820222 (from UK, 01865 820222)
or at 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK.

--
NavList message boards: www.fer3.com/arc
Or post by email to: NavList@fer3.com
To , email NavList+@fer3.com

   

Reply