Pulling up the sail at Bunnahabhain

I've never been so close to a sailing ship as with the Flying Dutchman at Bunnahabhain. I was interested in the triangular ropes either side of the sail. I wondered if it was a mechanism for reducing the force needed to raise the sail by using multiple ropes but inspection of the photographs shows that the ropes are probably there to keep the sail in a channel. There only seems to be one rope next to the mast that actually raises the sail. That appears to be a double rope around the pulley which means that the pulling force on the rope would only be half the weight of the sail.