> The load on a reefing line can easily match the load on the main halyard in
> very high winds, even though you have made the sail smaller (lift
generated
> by the sail is proportional to the velocity squared.). It should be about
> the same rating as your halyard block.
I though a little longer about the load on the reefing block and the answer
is not quite as simple as I wrote. If the reefing line goes though both the
reefing clew and reefing tack (front and back of the reef), the load may be a
little higher.
So you may want to go with a minimum working rating of 500#, rather than
400#, for the reefing turning block. 400# would probably be okay, but I'm
not sure, and as they say in Maine "nuthin too strong never broke".
Best,
Judy B