An example of our whisker pole hard at work holding the jib out while sailing downwind on the ocean
We installed a whisker pole before we left Portland, and it would be an understatement to say that it’s a complete game-changer for downwind sailing. Without a pole, the jib would collapse and refill with an alarming bang each time a wave rolled under the boat. With the pole, the clew of the jib is held in place so that the sail holds it’s shape even when the boat is rolling around. We can’t imagine doing an ocean passage without the pole now, and we’ll even spend the time to rig it up in inland waters in light air.
The inner workings of our whisker pole
Our pole is a Forespar Line Control model, which means that the length of the pole can be adjusted. A length of line runs through a turning block inside the pole to allow an inner tube to extend from the outer tube. Over the past several months, it became harder and harder to extend the inner tube – it was clear that something was wrong with the pole.
Being at a marina makes some boat projects easier. Working on the whisker pole on the dock was much easier than trying to do the job on the boat
We pulled the pole off of its storage system on the mast and lowered it to the dock. After removing one end piece to peer inside, it became clear the control line was no longer moving smoothly through its turning block. As Murphy would have it, the problem was easy to identify but difficult to solve. The offending turning block is buried deep inside the pole assembly, and access required removing both pole end caps to be able to push the turning block to the end of the tube.
We discovered this broken sheave when we disassembled the pole
Once we accessed the block, it was obvious what had happened. Vibration from a few ocean sailing miles rattled the axle of the block loose. Once the axle was only supported on one side, pulling on the control line turned the sheave sideways – this in turn pinned the sheave against the body of the block, preventing it from turning. So, the line just ripped the plastic edge of the sheave away from the sheave body, until eventually the line ended up completely off the sheave.
The marina’s drill press came in handy when drilling out the center of the replacement sheave (note the tinted safety glasses!)
We have a lot of spares aboard Madrone, but a spare sheave for a turning block located entirely inside of the whisker pole is not one of them. We do have a selection of other blocks, though, so we decided to improvise. We picked a block that seemed to be the right size and construction, and then drilled the block axle out so that we could remove the sheave. We then enlarged the hole in the sheave so that it would fit the axle on the turning block inside our pole, and popped it in place. Success!
Applying Tefgel to the head of the screw to help prevent corrosion between the stainless steel screen and aluminum whisker pole
Now we just need the world to get healthy so that we can go sailing again!
