Oops I've dropped the mast...Bummer!

[RickJ]

However, the idea of doubling the line to halve its work ... is fallacy.
That line still incurs the full weight of the load on the one-inch segment that's wrapping the block, top of mast.

Not so! Any line running over frictionless pulleys must experience the same tension at all points along its length. In the real world, friction will detract from this ideal a small amount, but not in the way you describe.

Doubling the line will halve the tension throughout. As observed, this lessons the chance of breakage due to exceeding the breaking strain, but it doesn't provide redundancy.

[Frank C]

Hmmmm ... actually Rick, I can see the logic in your statments.

'Course ... I also saw my totally opposite logic when I was typing ... hmmmm!
GOOGLE~!!!! GET OVER HERE!!

[atzserv]

I know basically nothing about pulleys and the physics behind them. I just know I enjoy the ease of use after putting them on the rudder mods and daggerboard, and I also added a triple to my mainsheet. While looking at the possible ease of having an electric winch on the trailer I was reading the user manual online and they mention using a pulley to lessen the load needed to pull heavier objects so the motor wouldn't overheat. Sounds to me like that statement makes the tension along the line theory the correct thinking.
Gary