This blog began in late 2006 with the planning and preparation for a circumnavigation of the world in my 39-foot sail boat Pachuca. It then covered a successful 5-year circumnavigation that ended in April 2013. The blog now covers life with Pachuca back home in Australia.

Pachuca

Pachuca
Pachuca in Port Angeles, WA USA

Saturday, January 21, 2012

Day 87 - D1 Shroud Jury Rig and Depth Sounder OK

I had a good night's sleep in segments of 90 minutes when the timer would wake me up for a look around. When I got up for the day I found a beautiful morning with a clear sky, a tiny sliver of a moon, and the sun about to rise. The wind was light, below 10 knots, and the sea was calm, with no heavy swell. Perhaps the South American continent and Staten Island were beginning to act as a giant breakwater protecting me from the relentless heavy swell on the west side of the continent. It was so nice that I stayed in the cockpit looking around and then looking up at the lower crosstrees thinking about some clever ideas Bob Carrol had sent to me about supporting the lower mast until I could replace the D1 shroud. ("Why didn't I think of that?")

I heard a familiar chuffing sound to my left and saw that it was a large dolphin doing his thing. It made me wonder how many dolphins, sharks, and even whales have passed by the boat while I was totally oblivious down below. (I remember spotting 2 whales out half way to Tahiti only because I happened to be at the first crosstrees doing something.) I thought too how in contrast to the terrestrial wildlife where the animals bark or howl or whine or honk or screech or roar or twitter or whatever, the deep ocean is a largely silent world where it seems like every creature plies his trade as quietly as possible.

Then I went back to the shroud problem and came to realize something that should have been obvious from the beginning. The D1 ("Diagonal 1") is the lowest shroud whose function is to keep the mast from moving to the leeward side due to either leaning or bending and seems to be under an enormous strain when sailing hard. But it seemed to me that it doesn't work completely alone. Obviously the D2 and D3 on the windward side restrain the mast from leaning, but it seemed to me that the leeward D2 and D3 shrouds also provide support because as the mast tries to bend, the leeward crosstrees push against those shrouds which resist the movement. It seemed to me that the absence of a D1 shroud would therefore put extra load on the leeward D2 and D3, but not lead to a catastrophic loss of mast. Wishful thinking? Maybe. I wish that I could speak with a rigger about it.

But wait, there was more thinking. The weather fax out of Wiluna in Queensland was again completely unrecognizable as even a fax. Then I got the idea of trying the Wiluna station in Western Australia and presto, I got a grainy but quite readable fax. (I could see tight isobars and another front at "gale alley" on the lower west coast of Chile and felt sorry for any poor bastard in that area desperately trying to get to the Horn.) So it looks like I may have passed a watershed where my communications with Australia are now orientated to my east rather than my west.

I had had my day of rest and was feeling better. After breakfast of buttered toast I would begin work on the replacement of the D1 by digging out the replacement (at least an hour of hard work) and re routing the restraining line to the mast to wrap around the port D2 or D3 shroud instead of the damaged D1. (I could imagine leaning back on either the D1 itself or the rope on the port side, the D1 deciding to part at that moment, and over the side I'd go.) If conditions were still calm when all was ready then I would try to swap out the D1 this day.

I started to work after breakfast and before long I had everything ready for doing the shroud replacement. Conditions were still calm so I proceeded with the job. The difficult part of course was making the swap at the upper end. I loosened the damaged D1 at the deck then went up the mast trailing a cord with which I would pull up the replacement shroud. Around my neck was a shopping bag with tools and materials. I wore my safety harness so that I could clip on to a mast step while I did the work. At top end I secured myself to a mast step then secured the damaged shroud with a lanyard so that when I freed it by pulling out the rig bolt it would not go crashing down on the deck. Everything went pretty well according to plan. I removed the cotter pin from the rig bolt, pulled the bolt out, the shroud dropped a few feet, then I hauled up the end of the replacement shroud with the cord. It took a lot of one handed fiddling but I got the shroud on using the same rigging bolt and a new cotter pin. I climbed down to the deck to savor the last few steps in my triumph and discovered my blunder.

The replacement wire was much too long and as soon as I saw that it was thinner than the D1 wire I realized that in Hawaii it was the Cap shrouds (D3) that had been replaced, not the lower ones. I also noticed that the lower fitting through which the rigging screw fit was split at the top of one of its two sides. I resolved the problem by in effect shortening the cap shroud by cutting off a section and joining the two remaining parts with bulldog clamps. I had one spare bulldog clamp in the hold. The inner forestay had 7 clamps on it, two of which did not clamp two wires but were there to prevent the sail from being damaged. I recovered three clamps from the inner forestay, leaving it with 4. That allowed me to use 4 clamps for the new shroud join. The result is that the port D1 now has 5/16" wire with a break load 5700 kg instead of the prescribed 3/8" wire with a break load of 7200 kg. But at least I've got undamaged wire in that position that will do the job as long as it looks intact. If the wire fails I've still got the other cap shroud from which I cut the bottom off for the inner forestay.

I was very fortunate in being able to work in the calmest day I've seen since the doldrums. While I worked I saw a lot of sea life including tiny black birds the size of sparrows which I'm sure were storm petrels and a totally white animal about 10 ft long that glided under the boat a few feet below the surface. There seemed to be a constant presence of those large dolphin except that the last one I saw was so big that I'm thinking that it must have been a whale, but I don't know enough about the size overlap between dolphins and whales to be sure. We were totally becalmed, with the wind an unworkable 6 knots. But the sun was out, the sea was calm, I had lots of sea life to keep me company, I had managed to do something about the damaged shroud, and I could rest, relax, and enjoy life on the boat. I couldn't complain.

At noon our position was 54S16, 063W02, giving us a n-n distance of 57 miles in the direction 024T. We had been becalmed for several hours.

After a light lunch in the cockpit I started to go into the cabin for a nap and heard the same light buzzing sound that I had noticed the day before. I tracked it down to of all things the ST60+ wind display. It was working fine but I thought this might be a good time to loosen the panel and have a look behind the instruments. The first thing I did was to pull out the Seatalk cable thus isolating them from the network with no room for doubt. This had no effect on the autopilot's "Seatalk Failure" problem so as far as I was concerned I had eliminated either of the two companionway instruments as causes of the problem. Just before I put the panel back in place I noticed a broken wire going into the back of the depth sounder. I jiggled the one next to it and it broke off with no effort. There was the telltale green color of corrosion at the breaks. I got out my electrical kit, put fresh crimp on fittings to the three wires, plugged them in and bingo! the depth sounder was working again.

I then wondered if the autopilot display, very exposed at the binnacle, might have a similar problem. I loosened the display from the mounting and found that the wire connections to the back of the unit were fine. I jiggled them around and they seemed firm. With that I thought that I had eliminated another possible cause of the problem.

As if on cue, the wind started getting some life as I was finishing up. Soon we were on the move again to the north at a modes 2.5 knots with an 11 knot breeze.

Unfortunately the breeze died and toward the end of the day we were drifting again. We must have been caught in a counter current because we were drifting to the south at 0.5-1.0 knots. I recorded our position at 0000 UTC to calculate the amount drift in the morning. The early morning weather fax showed that we were sitting under a 1010 mb high.

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1 comment:

Chris said...

Sounds like it was an interesting day.

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