Main Halyard Sheave

I recently removed the main halyard sheave from the top of the mast on Revolution, #526. It is aluminum, 6.75" in diameter, .5" thick, and has a 7/8" center hole in it. The hole has a brass or bronze bushing in it which reduces the ID to 5/8".

fit of 3/8" line on original sheave

This sheave has carried a wire rope for 25 years with little apparent wear. I am now changing to an all-rope (3/8") halyard, which the original sheave can handle without machining.

close-up of sheave groove

I also plan to have an extra aluminum sheave made up as a spare, and machined specifically for 3/8" rope. My machine shop will duplicate these at a cost of about $100.00 each. If anyone else is interested, I would be willing to arrange a volume purchase. For reference, I have attached photos of the sheave I removed from my mast.

South: The Endurance Expedition South: The Endurance Expedition

Shackleton's near-fatal journey to the Antarctic has received a lot of press in recent years. This is Shackleton's own account—quiet, understated, and riveting. It also describes the travails of the Aurora expedition, intended to lay the groundwork for Shackleton on the other side of the continent.

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Last modified: Wednesday 21-Jul-2004