Monday, August 26
26 51.6S
164 39.8W
Another fairly good week, despite a couple of setbacks. During this second week of our passage from Whangarei to Papeete, we sailed 653 miles (563 made good) and passed the half way mark! Only 1,006 miles left on this 2,200 mile passage.
The week wasn't without its 'exciting' moments with both gear and weather. We also had an interesting mystery to keep us occupied.
First, the gear problem. Gjoa has two, hot-switchable, autopilot computers which is a very good thing. One stops working, you just flip a switch to use the other one. The only problem is that they both send steering signals to a single, continuous running hydraulic pump. If this pump stops, so, do both autopilots and we'd have to hand-steer (almost impossible to do for extended periods with a short-handed crew). It's too expensive and complex to have two pumps, so, next best thing is to keep spares in case of breakdown. As I have mentioned previously, we have done a lot of work on the hydraulic system and replaced its pump motor just a few months ago. We rebuilt the old motor to keep as a spare and ordered extra brushes and seals for the new motor. Lucky we did. The pump runs 24/7 and it does create noise. At first, this was a big irritant. Now, the sound of the pump humming along is quite comforting and lets us know all is well with the steering. Until it stops! Just before dark, there was an anguished groan from the bowels of the engine room and then, silence. Some quick troubleshooting led us to believe that it was probably the brushes that needed replacing. Sounds easy, doesn't it? The problem is the motor location which is in the engine room underneath a lot of plumbing and wiring. The motor has to be dismantled from the pump to get access to the brushes. It took G most of the night and a lot of engine room gymnastics to get the old motor out, the new brushes in and the motor reinstalled. By 0230 we were underway again, what a feat. That was a week ago and it's been running fine ever since. The brushes were down to 11mm and shouldn't have needed replacing until they were 8mm. The recommended maintenance is to inspect them every 500 hours. Easier said than done. Actually, with something working 24/7, five hundred hours is only twenty days, so, on a lengthy passage they are likely to need replacing. Now there's a new item on our pre-passage departure checklist. Replace autopilot motor brushes whether they need it or not!
Next in line for a little bit of excitement was the weather. It seems like we can never have a passage without at least one gale, no matter what ocean or where in the world we are. This passage was no exception. The barometer went from 1014 to 1002 in just four hours. We knew we were in for it. The gribs showed two separate fronts would be hitting us quickly over the next thirty-six hours, one after the other, with a brief interlude in-between. And so it was. The first one came on, the waves were huge. It was a shock to the system (ours), so we hove-to for a while. When the interlude between the two fronts arrived, the wind dropped down to almost nothing and we couldn't maintain our hove-to position any longer and had to start sailing again. When the second front arrived we just kept going. It was a crazy night, dark, very fast and a rocky ride, winds 35+ for twenty-four hours. We had another twelve hours of moderating winds to finish off.
The mystery came on the day following the overnight gale. We hadn't seen a single ship on this passage. Then, all of a sudden we had six AIS (automatic identification system) targets pop up on our chartplotter screen and we were right in the middle of them! It looked like a fishing fleet, the target movements were erratic and slow. When we got within two miles of one of them we were unable to see it? Ok, the seas were high after the gale, but, we should be able to see even a small boat two miles off? Hmmm.... The ship names on the AIS info offered a clue. The ships were all named Chun I NO.218-xx (where xx was two digits: 19,20,21 etc.) All we could think of was that there must be a mother ship somewhere that had dropped nets with AIS transponders on them. We did eventually see a real ship: CHUN I NO 218, mmsi 416174900 with a valid call sign. One of the numbered progeny had an mmsi of 81562542 and an invalid call sign of @@@@@@. We'll be looking these up when we get back to shore to see just what it was we landed in the middle of. Can very large (assumed), unmanned nets floating around by themselves be a good thing? Are they motorized somehow to trawl by themselves, or, are they just moving with the waves? How do they keep their shape if they're not being towed? How large and deep are they and what were they catching in them? All interesting questions. Maybe there should be a new category of AIS for non-ship objects like this? I remember the first time we came across a buoy that had an AIS transponder on it we also spent a long time scanning the horizon for a ship only to realize it was a tiny buoy transmitting the signal. Great that they can be identified so easily, but, sometimes confusing.
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