Hopefully we get more than this done, but this is the list of things we need to do today/tomorrow morning.
I guess the rest is fairly optional.
I’ll probably delete this post by the end of the day. In the meantime, it’s just “thinking out loud” so to speak.. sometimes just the process of writing helps organize my thoughts.
my list for today:
So yesterday Brian was able to get the engine started… hooray!! and I drove to Rhode Island to pick up our mainsail… also hooray!! Stopped by for a visit at North Sails with my friend Jay, and got a tour of their loft… extremely cool!
In the interim, Jocelyn Towing (the boat launch company) called us back to say that they could slot us in on Saturday, which is both a bummer - no launch on birthday- and good, since it gives us a little more time to get some more things wrapped up before we’re launched.
Today’s wrap up items were the running of the engine (with cooling in place), the final install of the rudder (kinda need that) some additional battery installs, new blocking system for the roller furler and for the vang… all in all a pretty productive day, despite the frigid temp.
Oh, and if I do say so myself, the new floor looks amazing! Mark did a fantastic job getting it to match up with our existing floor, and three coats of varnish later - more to come in warmer climates - the salon is looking quite lovely again!
Tomorrow… more slowmaker (solar panel arch) and perhaps the wind generator install?
Finished most of the engine preventative maintenance,minus pump impellers which we’ll do soon. The engine started and ran OK after I left the batteries on the charger last night.
We’re hoping to launch sometime in the next few days, Thursday to Saturday.
Here’s where we’ll post our location to. I also put that ‘Our Location’ widget over on the right, which should auto-update.
Brian’s email will be kb1rec(AT)winlink(DOT)org. This email we can get via SSB radio, virtually anywhere in the world.
So I think it’s looking like I am getting an awesome birthday present this year… we’re launching either the day before or ON my birthday! Wahoo!! all the hard work is starting to really pay off! We were looking at the tides, and it looks like those are our best days to launch. So exciting!!!
In other news, we’re done the floor prep work and will likely varnish it today (Friday). Brian should be able to finish the battery installation today. We’ve installed new chocks and cleats on the bow yesterday. Our anchoring system should be greatly improved and very easy to use.
We’re not quite ready yet, but beginning to talk about when we’ll launch. We’ll likely take the boat to Salem, MA where we’ll have a dock we can sit on for [up to] a couple weeks as we finalize things and pack up. It looks like our best tide window for launch is between next Wednesday and Sunday.. the earlier the better. Targetting next Wednesday might greatly help us prioritize our remaining tasks :) Wow.
Let’s see, tasks at the top of the list:
Oops.
Upon further consideration, it appears that the new 210A alternator I got may not be appropriate for the boat. They suggest that you need to run 2 belts to drive the unit, which I may not be able to do. (I’m not certain if I really need 2 belts, though - my batteries will ‘only’ take 120A, a load that’s more comparable to the smaller alternators that use 1 belt. I’m not using anywhere near the 210A rating of the device.)
I’d also have to find/fabricate a bracket to mount the unit, do additional wiring, and so forth. It seems time-consuming. For now, I think we’ll go with the original 75A unit. This means that we’re only charging at 60% of our potential rate using a bigger alternator. Anyway, we’ll have to wait and see how much engine time we’ll be requiring.. if consumption is lower than expected, and wind speed is good (which it ought to be in the trades), we should be OK.
I’ve been doing the math on our electrical supply. It’s all guesswork, but hopefully it’s “worst-case” and our actual electrical usage is less than projected.
Here’s a fairly generous budget for electrical demands on a daily basis:
| Device | Draw | Hrs usage | AH/Day |
|---|---|---|---|
| Freezer(estimated) | 10 | 10 | 100 |
| Interior lights | 4 | 5 | 20 |
| Anchor light | 1 | 12 | 12 |
| Autopilot | 3 | 6 | 18 |
| Computer | 1 | 24 | 24 |
| Radio/ipod/misc | 2 | 6 | 12 |
| misc chargers/etc | 2 | 5 | 10 |
| Total used | 196 |
(for reference, that’s 2.35 kilowatt-hours in home terms - about the draw of a single 100W incandescent light bulb running 24hrs)
All the power that is used must also be replaced/regenerated. Due to inefficiencies, 20% more power has to be put back into batteries than is taken out. We’re looking at potentially 235AH of generation required per day, based on the numbers above.
That 235Ah has to be generated by a combination of solar, wind, and lastly the alternator on the vessel’s diesel.
Solar generates a predictable amount of power, in most conditions. It’s said on average to assume you’ll get 5 hours of rated capacity a day. This comes out to 600W-hrs, or 50Ah/day. Nice, but we’re still looking at some 185Ah remaining.
Wind power is variable. The following chart shows current versus wind speed :
(the curve is because wind power is related to the square of wind speed)
hmm, 185/24hrs = 7.7a. It looks that a 16 knot wind (average) is roughly our “break even” wind speed. On windy days, we’ll have tons of power.
All that remains after wind and sun must be generated via the alternator. If our consumption is in line with estimates, there will be days where we have to run the engine to recharge.
Our current alternator should generate nearly 75A. But, we’re in the process of fitting/upgrading to an alternator that should generate 120A. Effective charging ampacity is very important, because in the extreme conditions that there’s no wind or sun, all 235Ah has to be generated via the alternator. The difference between our old alternator and new would mean running the engine 2 hours instead of 3 to completely top off the batteries.
Brian | 
10 31st, 2008| 
