First Shakedown Cruise

Cruising To The West River

Looking south from Pilgrim at the eastern shore of the Rhode River. This point of land is marked on the Google Maps satellite image (clickable link on the previous page).   A view of the western shore of the Rhode River from Pilgrim. This point of land is also marked on the Google Maps satellite image.

Wednesday, May 9, 2007

We both slept late (about 9:00 a.m.) after a tiring day yesterday. Unfortunately, I didn't sleep very well, since I was too hot inside my sleeping bag, but I was too cold if I slept outside the bag. While I was lying in bed this morning, I heard the foghorn at Thomas Point Light, which is not too far away. Today's weather is quite different from yesterday's, with light fog / haze, very low clouds, and little or no wind.

The main project this morning is to set up the Honda generator and try it out. This will be a very useful piece of equipment, since Jerome is hoping to run it every few days to charge the house batteries.

One of the most difficult aspects of living at anchor is managing your electricity supply. Most cruisers nowadays insist on having and using the usual appliances and gadgets that consume electricity, rather than living an ultra-spartan non-electrical existence. Therefore, all modern cruising yachts have a large battery bank to supply the boat's electrical needs, plus an inverter to convert the battery power to ordinary 120-volt AC power for those devices that run on AC power. But the problem is, as you use all the gadgets and appliances, the boat's battery bank is slowly drained of power, and eventually the battery goes dead.

Obviously, the way to avoid this problem is to recharge the battery bank to replace all the power that you consumed. Depending on the size of the battery bank and the rate of electricity usage, cruisers might have to recharge the battery bank every couple of days, or perhaps once a day, or sometimes even twice a day. In a marina, you can simply plug into shore power to recharge the batteries, but that's not possible at anchor. Instead, you need to have your own miniature BG&E generating plant on board.

All boats have an alternator attached to the main engine that recharges the battery bank while the engine is running. So if you're motoring or motor sailing, you're batteries get recharged. What about when you're sitting at anchor for days at a time? Do you really want to run the main engine for a couple of hours every day? Think of all the accumulating wear and tear on that big, expensive engine just to spin the little alternator to recharge the batteries. If you figure out the life-cycle cost of the engine divided by the total number of operating hours in the engine's lifetime, this turns out to be a very, very expensive way to recharge the battery bank.

Therefore, it's highly desirable to come up with an alternative way of recharging the batteries. Some cruisers use solar panels and/or wind generators, but Jerome has decided to use the Honda generator. The generator puts out 13.3 amps of clean 120-volt AC power, so the idea is to connect the generator to the boat's shore power receptacle and pretend that we're hooked up to shore power, letting the shore charger recharge the batteries.

There's a tricky "gotcha" in this scenario. Most boat shore power circuits are set up to use 30 amps of 120-volt AC power, since that's the typical amount of electricity that marina dock wiring provides. But the Honda generator only provides about 13 amps, so if the shore charger tries to suck 30 amps of power out of the 13-amp generator, the generator will overheat and trip its circuit breaker. Not to worry—it turns out that the shore charger is sophisticated enough that it can be reconfigured to use less than 30 amps of power, which saves the day. By pressing a few buttons on the control panel, Jerome told the shore charger not to overload the generator, and presto, everything works fine.

There's actually another "gotcha" that I haven't mentioned yet. One of the biggest energy consumers on the boat is the refrigerator/freezer. Boat refrigerators are very different from home refrigerators. Your home refrigerator is always plugged into AC power, so it is designed to use a little bit of power over a long period of time to keep the refrigerator cold. But boat refrigerators have the refrigerator compressor connected to the engine (like the air conditioner compressor in a car), so they are designed to use lots and lots of power (supplied by the engine) over a short period of time to keep the refrigerator cold. The idea is that while you're running the engine to recharge the boat's battery bank, you can also be cooling down the refrigerator. But we just came up with a way to avoid running the engine to recharge the batteries, so how are we going to keep the refrigerator cold? (Problems, problems!)

There are a couple of possible solutions, which Jerome will be investigating over the next several weeks. Jerome's boat refrigerator also has a 120-volt AC compressor similar to a home refrigerator, and this compressor can be powered up any time he's running the Honda generator. A couple of hours every other day might be enough to keep the refrigerator cold. Even if that's not enough, it will certainly reduce the amount of time he has to run the engine-driven compressor. And you don't want to run the engine-driven compressor for too long, because it makes the refrigerator too cold and freezes the salads and eggs! All those details are still to be determined.

Anyway, that's a long explanation of the reasoning behind using the Honda generator and some of the problems that arise and must be solved. As Jerome makes the transition from shoreside living back to sailboat living, these are some of the problems and tradeoffs that he will have to address. Since he has already gone through the process once before (with Herman Melville), he is well prepared to make the transition again.

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