Tuesday, December 31, 2013

All systems go

We’ve been slowly starting up systems on the boat after its 6 month sleep.  A couple of days ago I finally got around to firing the main engines, which didn’t go completely smoothly.  The starboard side started right up but the port was a little stubborn.  I think it was probably related to the fact that both the generator and the Webasto heater draw off the port side close to the engine intake.  I probably should put a check valve in there somewhere to prevent the other users from pulling fuel back out of the engine.  It was no big deal but I had to bleed the pump a couple of times before it finally fired off and stayed running.  Both times the pump had fuel in it but there was a burst of bubbles came out when I cracked the front bleed screw.  I bled it once, cranked it and it fired off but wouldn’t rev up and died out quickly.  I bled it again and that time it took off and stayed running. Both times the “bleeding” consisted of opening the two bleed screws and pumping a couple of times on the primer so it wasn’t really much of an ordeal.

Yesterday I fired the genset – it took a bit of cranking to start but it stayed running.  Its always been a little more forgiving of air in the fuel line. 

This morning we untied all the extra lines.  When we’re gone I like to double up as many lines as possible.  After a quick lunch we took off and arrived in Chemainus around 4:00.  Everything worked well on the way.  Our new computer makes a wonderful nav system. 


The touch screen has a few “issues”.  It has nothing to do with the nav software – the “touch” part just goes away on its own fairly regularly.  I’ll have to dig into that but so far that has been the only real problem.  When we first hooked the computer up we were both a little sceptical.  I think we were just experiencing change.  I can’t see that Window 8 is a whole lot different than its predecessors but there’s enough differences to make our life difficult off the start.  Combine those differences with the touch screen issues I already mentioned and we weren’t certain we’d made the right decision.  A week later and we’re pretty comfortable with our new toy and pretty happy with how it works. 

Until today I wasn’t 100% sure that the link to the autopilot would work.  On the previous system I had an RS232 port which drove the serial cable to the autopilot.  The new computer doesn’t have anything as primitive as an RS232 port so I had to come up with a USB to RS232 adapter.  I’ve got one kicking around somewhere – actually I think its somewhere on the boat – but of course I couldn’t find it when I needed it.  Fortunately London Drug had one in Duncan but I was by no means certain it was going to work.  When we got down by Separation Point this afternoon I activated the route in OpenCPN and told the autopilot to start following it.  Wonder of wonders it not only followed the route, I think it followed it better than it has ever done in the past.  On the old system there were times when the boat would seem to lose its sense of direction for a while.  It was like the autopilot would stop getting a signal from the computer.  Not so today – I don’t think we drifted 100 feet away from my preset course, ever. 

Its not dead simple to drive a boat by computer – there’s all sorts of negotiations that the computer and the autopilot have to go through.  There’s lag built into the GPS position information, the vessel has momentum which delays the start of turns and prolongs the end of the turn, even the degree of the turn affects how the boat navigates the turn.  On a minor course correction the boat barely moves off its heading but on a serious turn it builds up some significant rotary momentum during the turn and somehow that energy has to be managed as the boat comes out of the turn.  In the same way that you have to lead the control input on an airplane, you have to lead the inputs for the boat both to initiate a turn and to cancel the turn.  When you’re driving manually all that integration of motion and control input happens naturally if the skipper has any feel for the boat.  Its probably the most important measure of a skipper – how he manages to integrate all that information and how much feel he develops for how the boat handles.  For two separate computer systems to sort that out seems nothing short of miraculous.

Tonight we have tickets to “A Wonderful Life” which is the dinner theatre presentation for New Year’s Eve.  We’re paid up for three nights here on the dock – after that we’ll figure it out. 

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