GL: "Cutlass" Bearings

[fred]

Mac,

The type of wood may have been called Lignum Vitae.  My father used to
provide it to the US Navy for use on submarines.  They lined the foot-thick
prop shaft with 2 inch-thick blocks of this super-heavy slightly greasy
wood as a cutlass bearing.  The benefit to this wood was it's greasy
quality and super hardness made it pretty much impervious to seawater, and
it allowed the bearing to run silently, making it undetectable by enemy
passive sonar.

No that's not a military secret, Lignum Vitae had been used as long as
there have been prop shafts, but apparently the Navy liked it a lot.
Sometimes the old ways were best.

Dad also supplied the belaying pins (portable cleats like small baseball
bats) for the sailing warship Constellation about 30 years ago when she
first arrived and was refurbished in Baltimore.  Because of the strength of
this wood, it was a good material to use.

I have a carpenter's chisel hammer made of it and it looks brand new after
being used for 30 years by me for nearly everything.

Now ya know.

Fred W.
Tug 44
http://www.tug44.org/



At 08:32 PM 10/2/06 +0000, you wrote:
>A recent (2006) edition of "Passage "Maker Magazine"
>had some interesting history on cutless bearings.  The
>basic history is that these were developed in the British
>mining industry (if I recall) for pumps to keep mines
>pumped out.  Originally some sort of wood was used
>for the bearing/sealing and a mine ran out of the very
>specific wood.  An engineer came up with a substitute
>that was very similar to what we use on our boats.  He
>named them "cutless" because they CUT LESS and lasted
>MUCH longer than the originals.  A company was formed
>to manufacture these "CUTLESS BEARINGS" and a drawing
>of a "CUTLASS" sword was chosen as a trademark.
>
>ERGO, we are using CUTLESS bearings and  NOT  cutlass
>bearings.
>
>If I remember by the time I get home, I will look up the
>article and post a reference this evening.
>
>D C "Mac" Macdonald
>m/v Another Adventure
>Grand Lake - Oklahoma
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