Re: Pulleys (Spanish rig?)

[Leigh Palmer <palmer@SFU.CA>]

> I recall what a pleasant thing it was to search the PHYS-L archive
> at Prof Hake's urging, which helped turn up a comparable experience
> to my acoustic grating 'whistler' experience in a country road.
>
> So now it is my pleasure to offer a reminder of the easily searched
>  resource this archive provides.
>
> <http://mailgate.nau.edu/cgi-bin/wa?S1=phys-l>
>
> (Search the archive: use 'canoe' for the keyword.)
>
> "...This problem is interesting. It involves simple mechanics and spatial
>  relations. It would make a challenging high school mechanics problem.
>
>  The rig may be seen at http://www.sfu.ca/~palmer/canoe.pdf

Thanks, Brian. I sure didn't remember that one! I will have to get
back to that project sometime soon. The pulleys I used before had
far too much internal friction to use to lift the canoes, though
most of the friction was in the ropes running over the gunwales (I
showed pulleys in the diagram, I think). They worked fine coming
down, demonstrating well the inherent stability which keeps the
canoe horizontal, as I conjected. I guess I invented this lashup.
I've never seen it elsewhere, and given that it doesn't really help
in storing a canoe using cheap pulleys (leastways it doesn't yet) I
don't think it's worth patenting. I've got enough space that I can
lean the canoes against a fence at ground level, and that's what I
do. I've bought a two-wheel contraption to wheel them down to the
lake so I don't have to heroically throw a canoe onto my shoulders
as I used to do.

Leigh