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Thursday, October 20, 2005

The future of marine electrical systems

Interesting article by Nigel Calder in the October 2005 Issue of Professional Boatbuilder Networking: The 3-Cable Boat.

3-wire Wiring harnesses are coming to the marine industry! No more complex bulky runs of two conductor wire from distribution panels to devices! This technology has already been used in production automobiles for years and recently has started to appear in motorcycles (BMW).

Now if this stuff has matured by the time I get to the electrical system, I might consider it! It would certainly cut down on the costs of installation and the addition of new electrical devices after build completion.

cool...

Addendum:
Here are some links to some manufacturers who make these sorts of systems for RV and Aerospace:
Moritz Aerospace
Wes-Garde Products

Sunday, October 09, 2005

Temporary Floors, Dust Collector, Design...

This weekend, installed about 6 feet of temporary floor to give some work area when the floor timbers go in. Also more permanently installed the dust collector in the forward hatch to help keep things clean when I start grinding and sawing things again. Updated the link on the blog page to the "Latest Design". It should work now. ...later

Wednesday, October 05, 2005

Thoughts on Engines...

I know it is WAAAYYY to early to seriously consider a brand and model for an auxilary power plant for the WestSail. But, I am in the midst of CAD work and I need some size reference based on suitable make/model of diesels for the W42. Horsepower... Rule of thumb says 1hp per 500lbs of displacement. A calculator I found says 32,000lbs of displacement with 40 feet of waterline will need about 63 horses to drive it up to a hull speed of 8.5 knots. Size... I want to make the engine room as tidy as possible and leave as much room for other mechanical accessories like genset, water maker, etc. etc. So, naturally, the smaller the better. Technology... Modern technology has definately come to the marine diesel industry. No longer do you have just "plain" diesels. You also have turbocharged, and intercooled turbocharged. Both give an increase in HP with the same cylinder displacement and physical overall size. Current thoughts are stay with KISS (keep it simple stupid). Going with a turbocharged engine seems to violate this prinicipal (at least to me). There MUST be increased maintenance with a T/C engine. I am sure turbo technology has come a long way (I remember when turbo's got a bad rap with autos in the 80's), especially on diesels. But, I dont know if I want to take a chance. I have read reports turbos getting their blades torn up, bearings going out, etc. etc. Do I really want to deal with that? Right now my feeling is 'no'. So, I am leaning toward naturally aspirated diesels. Ratings... Ratings (or duty cycle) is the latest ad craze with manufacturers. They post different HP specs based on duty cycle and list these under things like M1, M2, M3, etc. ratings. This typically means that the stated HP is only for a certain duty cycle, %100, %80, %50, etc. I dont know the full details, but suffice it to say my interest is in FULL CONTINUOUS 100% DUTY CYCLE. You have to expect, when cruising that you might need to run your engine for very long periods of time (no wind?). So what are ideal make/models? Yanmar? Well, I would prefer to go with Yanmar. We have a 3GM on our 28 foot sloop and it has been running great with nearly 700 hours on the clock. Unfortunately the low end of the 4JH series is short on horsepower until you go turbocharged. It is a nice size however, Volvo? We had an MD7A in our sloop and it served faithfully. But parts were VERY expensive. Despite the newer small volvo engines being Perkins blocks, I believe that if it is painted Volvo Green, it will cost 3x more as it would otherwise. Westerbeke? They have a low RPM 64 hp naturally aspirated engine (model 64A) that looks ideal. Just a bit bigger than the Yanmar 4JH series. And it looks like it could be mounted very low in the bilge. So, think I will use the Westerbeke as a reference. Anyone got some more thoughts? opinions? (I opened comments on this post). ...later!

Sunday, October 02, 2005

Composite replacement for Plywood

So a number of things have progressed over the past few weeks... CAD: Local owners of a W42 'Nightingale', who were in possession of original blue line drawings, loaned them to us while at the WestSail rendezvous last September. I had a company in Seattle scan them in. This has given us more accurate dimensions than the ones I had to "guesstimate" from the construction manual drawings. As a result, I pretty much had to start the CAD drawings all over again. No big deal as we wanted to make a few changes after seeing Nightingale. MATERIALS: My wife encountered the president of Coosa Composites at the boatyard as he was making the rounds in the PNW showing off their fiberglass/foam composite "replacement" for plywood. This stuff is pretty cool. We ordered a 3/4" inch sheet of their "Bluewater 20" from Fisheries Supply in Seattle, to see what it was like. Well, this weekend I cut off a section from the 8x4 foot sheet and did a few test laminations. This stuff is very stiff and strong. Superior laminate adhesion than plain plywood. And the specs exceed that of plywood for strength. It cuts VERY easily (a circular saw goes through it like butter), much lighter than plywood (about 40% lighter). And IT DOES NOT ROT. (and water retention is very low < 1%) So, it looks like we will be using this stuff for floor timbers and bulkheads using traditional hand layup for tabbing. This will be much faster than the previous plan of glass over foam (whether vacuum infused or not). The downside is that it is pricey. This one sheet was about $180, and that was at builder's pricing. Other things ongoing: I still need to get some stainless parts drawnup and to the fabricator. Next weekend will see the transferring of dimensions from the inside of the hull for bulkhead templates. Thats all for now.