Galena's main autopilot is an aging Aries wind vane installed back in the '70's. Aside from the bearings locking up and needing to be replaced the only maintenance item are the control lines running from the servo-rudder arm to the tiller.
These lines can come under considerable stress and consequently are subject to wear at the ends and all four turning blocks. I've replaced them three times in the past 10 years. It was time to do it again.
The old control lines on the swing arm of the Aries' servo-rudder
This time around I'm using a very high-tech, low-stretch, single-braid line that I picked up during my recent visit to New Zealand. The only concern I had related to the treatment of the ends of the lines. With the larger diameter double-braid lines I simply tied a stop-knot in the lower ends and that worked. Although there was considerable abrasion right at the knots.
This time I decided to use a stop bolt with large-diameter washers to keep the line away from the cast aluminum flange. That required putting a splice in this very slippery line.
The new control line on the swing arm with the 'stop bolt' in the loop
I'm using a locking Brummel splice.
The first part of the Brummel splice in the single-braid line
Notice that the lines pass A-through-B and then B-through-A. This forms a locking set. Following this up with tucking the bitter end back through the center of the standing part makes a splice that is said to maintain 95% of the strength of the line.
Looking forward to another few years of service before having to replace this line again.