{"id":666,"date":"2006-11-23T00:00:00","date_gmt":"2006-11-23T00:00:00","guid":{"rendered":"https:\/\/setsail.com\/?p=666"},"modified":"2009-04-15T08:57:43","modified_gmt":"2009-04-15T13:57:43","slug":"s_logs-dashew-dashew309","status":"publish","type":"post","link":"https:\/\/setsail.com\/s_logs-dashew-dashew309\/","title":{"rendered":"Sonar for Cruising, Part 5: Installation"},"content":{"rendered":"
SONAR for Cruising, Part 5: The Installation.<\/div>\n

<\/p>\n

We’ve been hauled out the past week, installing our Furuno 270 CH SONAR and doing a few other chores. While we were initially concerned about the complexity of installing this gear, as it turns out it is quite a simple process.<\/p>\n

The wiring is the easiest part, and we took this on ourselves. There are five elements to be connected in the system. Starting with the SONAR transducer and its hoist mechanism (installed in our forepeak), there is a power cable to be connected and then a special cable supplied by Furuno with plugs on both ends between the hoist and the "black box" located beneath our saloon. The black box also gets a power cable from the DC panel.<\/p>\n

Next, there’s a smaller black box with a special Furuno cable, again with plugs on each end. This smaller box connects to the SONAR control and to the display monitor as well as the primary black box. This box also is tied to the GPS, so it knows the boat’s position with a NMEA 0183 connection, again with a cable supplied by Furuno.<\/p>\n

The entire process took about four hours for Steve with a couple of hours of help from our friend Dave Wyman pulling cables.<\/p>\n

What we thought would be the more complex part of the process was the installation of the hoist mechanism and transducer (what Furuno calls the "sound dome").<\/p>\n

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Here is a photo of the sound dome’s innards. The black six-sided transducer is rotated and angled with special motors as the user changes the scanning angles.<\/p>\n

For this part of the installation we asked Channel Islands Marine – and its owner, Mark – to give us a hand. They are a Furuno dealer and have installed a bunch of these units. <\/p>\n

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The first step is to measure in some specialized oil, in which the transducer floats.<\/p>\n

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Note this no-drip pouring lid. We’d like to have these on a variety of containers!<\/p>\n

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Mark and his partner Jeff then assembled the sound dome cover with filled with oil onto the transducer assembly.<\/p>\n

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There is a cable coming out of the top of the sound dome which is run through this very heavy stainless pipe.<\/p>\n

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And then the pipe, with cable inside, is screwed into the sound dome assembly.<\/p>\n

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That stainless shaft then runs through a packing gland and is clamped onto the hoist mechanism, as shown above. You can also see the flange in this photo, which is welded to the 6-inch (150mm) schedule 80 piece of pipe, which is in turn welded to the hull. Furuno’s engineers were thinking ahead here, as the pipe is a standard size, as is the flange.<\/p>\n

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In this photo you can see the hoist mechanism together with an emergency hand crank. Once the electronics covers are replaced the unit is quite tidy. As this resides in the forepeak, directly under a large deck hatch, we are going to keep it covered with a "dry bag" so that if there are any drips, they don’t create problems. <\/p>\n

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Mark is shown here with the fully extended sound dome. We are using the long stroke model, which gives us up to 14" (350mm) of exposure. We are not sure how much we will need. This is a very shallow installation by Furuno standards – the canoe body is typically 18" (450mm) immersed at this point. However, the bow wave disturbance is tiny and this is in the laminar flow area of the hull, so we’re thinking turbulence around the sound dome should be minimal (other than what is caused by the round shape of the dome). The extension is adjustable from inside the boat, so we are going to start out with 7 inches (175m) of exposure and increase or decrease from there depending on what we find. We want to minimize exposure as this reduces drag underway. <\/p>\n

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With high-speed planing hulls, it is necessary to build a ramp ahead of the sound dome housing, which creates a negative pressure area behind it as the water rushes by. This prevents water hitting the aft edge of the tube and forcing itself up and against the seals. In our case, given the flow we should experience, we did not think this was necessary. But just in case we let the forward edge of the pipe stick down 3\/4" (19mm) deeper than the aft side, and then faired this in the West Epoxy and microballoons.<\/p>\n

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In an ideal world this would be mounted on center. But we have a deep structural girder on center which we did not want to interrupt, so the sound dome is offset to port.<\/p>\n

You are probably sitting there wondering how our amateur wiring job turned out. We were certainly curious and maybe a little nervous when Mark turned on the circuit breaker and lit up the system. And…it worked just fine!<\/p>\n

We’ll be back aboard Wind Horse<\/em> this weekend and will report on the process of learning to navigate with SONAR.<\/p>\n","protected":false},"excerpt":{"rendered":"

SONAR for Cruising, Part 5: The Installation.<\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4],"tags":[],"class_list":["post-666","post","type-post","status-publish","format-standard","hentry","category-dashew-blog"],"_links":{"self":[{"href":"https:\/\/setsail.com\/wp-json\/wp\/v2\/posts\/666"}],"collection":[{"href":"https:\/\/setsail.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/setsail.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/setsail.com\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/setsail.com\/wp-json\/wp\/v2\/comments?post=666"}],"version-history":[{"count":0,"href":"https:\/\/setsail.com\/wp-json\/wp\/v2\/posts\/666\/revisions"}],"wp:attachment":[{"href":"https:\/\/setsail.com\/wp-json\/wp\/v2\/media?parent=666"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/setsail.com\/wp-json\/wp\/v2\/categories?post=666"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/setsail.com\/wp-json\/wp\/v2\/tags?post=666"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}