31 March, 2010

Preparing to upgrade engine battery power flow

Sail and the wind is the best source of power on a boat but second to that electrical power is critical not only to run the lights and chart plotters but to start the engine.  In 2006 I installed a new battery bank to assist the house bank.  It involved running a new set of battery wire from the new bank to the switch board and then rewiring the main switch panel.
Malua always seemed to lean over to Starboard because the main battery bank of six 6 volt 200Ah are located under the quarter berth on the starboard side.  The choice for the new battery bank was easy - it had to be on the port side.  The only reasonable place was under the aft cabin bunk so that is where it went.  I could only fit four 6 volt  Sonnenschein SB6 200 amp-hour batteries into the space.  No matter this bank drives the electronics and does not need as many amp-hour as the primary bank.
In the process I took the starting battery out of the circuit but left the cables running to the main switch board.  I estimated that the combined power of the 10 batteries would be sufficient to start the 50Hp Yanmar with ease.  In fact it is more than I require but on starting the engine the power draw leads to a drop in voltage to the chartplotter and it does not like it especially if the battery voltage is low.
The solution is to reintegrate the starting battery into the main switch board unfortunately the starting battery is not the same as the house batteries and therefore they have a different charging regime.  I cant just add the starting to one bank.  The starter will be connected directly to the starting bank and then add a switch to the cable from the generator cable to the main house bank and the starting bank.   To start the switch will be on starter, to charge switched to both or main bank.
Well that is the plan, all I have to do now is cable in the new switch and test it when Malua is back in the water. 

15 March, 2010

Marine Rescue Helicopter Training

The Southcare helicopter requires of their paramedics undergo highwire training from the water and vessel to the helicopter. Batemans Bay Marine Rescue willingly provided a platform for this training. When I have been involved in the past it has convinced me that I do not want to be in a position to be plucked from the sea by a thin wire from a helicopter. 060.JPG

We are required to steam 20 degrees off the wind at about 8 to 12 knots so the helicopter can hover above us on our port side.  If anything goes wrong the helicopter will swing over to the port side to ditch.
The parametric have to prepare themselves in our vessel then as the wire is lowered they connect and indicate that they are ready to be lifted.  If all goes well they rise up from our deck BUT if there is a swell then we go up and down and the helicopter hovers above.  The wire gets tight and the winch man has to let some go then when everyone is ready up they go.
The noise is ear splitting and the spray too great to see without goggles.  The whole process is a good exercise and a warning not to get into a situation that you will need the high wire.
To watch the exercise and my trip down the coast click on youtube http://www.youtube.com/watch?v=zJ1-bwKfrt8

Annual Mooring Maintenance

It time for the annual mooring maintenance not that last year much maintenance was undertaken because the previous year I had replaced the shackles and the mooring line to the buoy. A year ago the only thing that was needed was to replace the stainless steel mouse wire through the nuts of the shackle.
Again this year Stephen took me out in his boat Tegwen towing his tinny from which I could access the mooring. This year the water was much warmer at 23.5 C however I decided to wear a bottom half of a wet suit before donning the scuba and slowly sinking down into the murky waters of the low tide. To my horror as a reached the end of the mooring line I discovered the thimble was missing and two of the three strands in the eye splice had worn through. The whole mooring was hanging by 10 thin strands of the line. I proceeded down the chain to the shackle at the concrete block to find this to be buried in sand. I tried to undo the nut on the shackle with two large shifting spanners but was not able to get any movement from it. The next time that is removed will be with a grinder or oxi torch.
I attempted to undo the top nut from the bolt through the swivel shackle. That was not going to budge either. Not even when I was standing in the tinny and using the full force of the two large spanners. Unfortunately the swivel end has seen some corrosion and that will have to be replaced in a year or so.
Having attached another mooring line to the top chain Stephen and I winched the line up from the bottom just to the surface to work on the swivel. I also had to clear the weed from the line. Not difficult but great care has to be taken not to cut your hands.
Now to undo the nut from the bolt on the swivel. Not even with a hard surface to work from would the nut budge. Another grinder job.
I cut the old mooring line from the swivel and attached the new line below the swivel because the shackle was not large enough. That will do for a few months but will have to be seen to if used.