On 23 Dec 2003 10:28:04 -0400, Gregg Germain
wrote:

Yeah...tapered frames. All very well - removes weight at the sheer
etc. Helps performance.

But I'm here to tell you it's an infernal nuisance when you are
rebuilding (possibly easier when building from scratch).

first just getting the frames out of the flitches is much more time
consuming. They start 1" x 1" at the sheer and increase 1/16",
moulded and sided, for every foot of length.

I don't think it took that much longer in a shop that did it
routinely. I have an anecdote that explains.

When I had a loft in Boston for instrument making, through the mid
1970s, the Charlestown Naval Shipyard auctioned off its equipment.
Everything that could be easily moved was collected in a large room,
but a few things stayed in place.

Among thes was two machines I was later told were "ship saws." They
were effectively "tilting arbor" band saws with stationary tables
about 6 or 7 feet square, 6-foot wheels, and a yoke whose exterior was
a semicircular arc centered on the hole in the table where the boade
passed. The lower wheel was in a slot in the follr, so the table was
at a reasonable working height.

The outside of the arc had gear teeth, and there was a crank located
so a man could turn it while he observed the cut from above. There
were degrees of tilt marked on it as well. I tried to imagine how this
was used, and why there were two of them.

Three brothers who had a millwork shop on the first floor of my loft
building were able to describe its use. They had worked for a yard
that built small craft for the US Navy during WW2.

That machine was used to make sawn ribs.The curve was transferred from
drawing to the top surface, and numbers indicating the angle of the
plank marked along the curve.

Two men worked together to cut the ribs. One fed the piece into the
saw, supported by the always flat table. The other would turn the tilt
crank to produce smooth transitions of tilt from one number to the
next.

Thus, the outer surface of the rib would closely approximate the inner
surface of the plank that would eventually lie against it. And these
saws could do ribs for jobs as big as the restoration of the USS
Constitution.

Nearby was a station for a 36" DeWalt RAS, which had been moved to the
warehouse. That was an astonishing machine to see. It had a power
feed.

On the ground floor below the ship saws was a band sawmill to saw logs
that came in directly from schooners tied to the seawall. A coiled
blade lay on the floor. Its width reached my knee from the floor. I
can't imagine how you would coil a bandsaw blade that big.

I don't know what happened to these magnificent machines. I hope they
are in a museum but if they are I don't know where it is.



Rodney Myrvaagnes J36 Gjo/a


"In this house we _obey_ the laws of thermodynamics." --Homer Simpson