Monday, March 4, 2013

Still rewiring the fly bridge


We took Saturday off from the boat to visit the New Britain Museum of American Art to see the current exhibition, Toulouse-Lautrec & His World. It was a great opportunity to see and read about many of his lithographs that have become so familiar and examine literally hundreds of his sketches, some of which are beautiful fragments on tiny pieces of paper.  The information displayed about each item in the exhibition was as fascinating as the drawings and lithographs themselves.

This museum is simply a gem with a collection that numbers over 10,000 items.  Even if you get lost in New Britain trying to find it, the New Britain Museum of American Art is well worth a visit.

Sunday found us back on the boat but not before some substantial nourishment from some prize-winning french toast courtesy of Frances and the Sunday New York Times.

Once on the boat, we uncovered the bridge, collected our tools and assumed the position on our back under the upper helm. In a previous post, we described installing terminal strips for making the numerous connections +12 VDC but that needed a little more work to separate the loads fairly evenly between the port and starboard battery banks.

Even more important was the ground circuit since all the current drawn by everything returns to the batteries on the ground wires.  Silverton used two 16 gauge wires from the engine blocks to the lower helm and then to the bridge. We added an additional 8 gauge ground cable for the lower helm and an second one for the bridge. The question was, how to connect all those grounds from the radio, radar, depth sounder, etc., in a way that would give each circuit the best conductivity.

We found a ground buss bar made by BlueSea. Not inexpensive, ($12.95 each), but just what we were looking for.


It's made of tin plated copper, so you have to go easy when tightening things down.

We began on the starboard side, wiring our new #8 ground cable to one end of the buss bar and then running a second section of #8 cable to a second buss bar mounted on the port side. We re-routed and reconnected to the buss bar as many grounds as we could. In some cases, we left the connections to a previously installed barrier strip in place, since they don't carry much current. A couple of contacts on that barrier strip are used to make GPS connections from the chart plotter to the radio and the radar and since they work fine, it is good enough for now.

The starboard side looked like this:



 We know how sloppy this wiring looks. A couple of times we have considered removing all of the bridge wiring and starting over but for now, spring isn't far off and a project like would take us a month or more.  Besides, sloppy wiring is pretty common in production boats since it's hidden from view. Maybe we'll rehabilitate this bridge wiring next winter..

On the port side of the helm, we had some difficulty finding a place to mount the ground buss bar. We ended up moving the previously installed +12 volt terminal strip up a little to make room.


The +12 volt terminal strip comes with a neat plastic cap that covers and protects the contacts. Like the starboard side, we left the previously installed terminal strip (shown at the top left) where it was. The right side provides grounds and the left side is +12 volts. There are only two connections left on it and neither are critical.

Those coils of gray wire shown at right are from the radar. Unfortunately, those are wires we can't cut and shorten.

The primary DC connections to the bridge are now all in place. The new #8 cables effectively parallel the original factory DC wiring so we should have ample capacity even under maximum load conditions such as radar on, marine radio transmitting and operating the air horn all at the same time. Actually, that could easily happen if we were operating in the fog.

This bridge wiring project involved removing lots of old wire and butt connectors, terminals, masking tape and one old factory-original terminal strip.


The next step will be to connect the new bridge wiring to the port and starboard battery banks through circuit breakers mounted in the engine space.

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