Help Me Select a Pair of Davits-ordering tonight!

[jpendoley]

Hello Forum-The new owner of Tropic Bird here. I urgently need to install davits. Why? Because live aboard and need to install two 140 Watt Kyocera panels to keep the reefer going and figure I can do that easily on top of davits and  solve the dingy problem as well. My dink is a 9 foot Achilles air floor with a 5 HP Honda, should not be more than 175 lbs max. The panels might be 30 pounds total. 
I want the davits high enough to avoid the engine in the water when heeling problem.
All input greatly appreciated.
Jim

[INCOMMUNICADO]

Jim, I will try to give you my thoughts on davits for our 365s just remember I'm old and crazy as a loon. The davits we have on Incommunicado are stock from the factory and are only two to three inches above the stern rail. We have one 165 watt Kyocera solar panel mounted on the davits.  The problems start when we raise our dink all the way up. Our dink is a ridged AB 10' 167 lbs. outboard Yamaha 15 two stroke 112 lbs. Ok now your thinking what the hell moron that's about 300 pounds well it's not the weight, the davits are good to around four hundred pounds. I mount the outboard on the stern rail and put extra lines on to hold the dink in one place. This works well at the dock, in the river or the intracoastal waterway. The problem is clearance from the ocean. I think at some point I will have custom davits made with a wind generator mount and rod holders. The clearance must be three inches from the mizzen boom for the solar panels. Still when we head offshore, the dink will be upside down on the foredeck. I do hope this gives you more to think about. If it were easy everybody could do it. Allen

[P69]

The only thing I can add is that I have a pair of St Croix davits with fixed triple blocks at upper end. Don't like the fixed blocks because the lines cross,  3/8 line barely fits, but skinnier than 3/8" line is hard on hands, but would roll through blocks better. Also, Can't remove blocks when not in use, so the line is constantly in the sun. Only way to remove line is to unreave them.  Maybe I am doing something wrong with the lines, but the fixed blocks are a PITA, line constantly twisting.

What I have:
http://www.davit.com/rotating.html

[Della and Dave]

We have the Forespar Nova Davits and like them.  They keep the dingy pretty high, but mounting would determine how high to a certain extent.  Ours are pretty old now, and Forespar has changed the design to a certain extent.  We don't have any solar panels on ours yet.  The weight limit is 350 lb.   http://www.forespar.com/products/boat-nova-davit-lift.shtml

[S/V Deo Volente]

This was discussed a few years ago, it may help
http://www.pearson365.com/forum/index.php?topic=832.0

[PeteW]

I'm really struggling within the whole concept of davits for the purpose hanging and then launching a dinghy. Don't see myself climbing over the stern to get into a dinghy on the Pearson 365. What makes more sense is pulling the dinghy along side either starboard or port and using the boarding ladder that attaches at either boarding gate. Under way I would prefer to tow my dinghy from the Sampson post at my stern. At the marina I can store it in my slip or on the dinghy dock (no charge at my marina)

For the solar panel issue I'm leaning toward panel that swivel from the rigid life rails port and starboard. ( I don't have life lines) In the down position they will clear any pilings pulling into a slip. Mounting them to davits render the davits even more difficult for boarding. Your marina may also want to charge for the additional length overall.  But for much less money you can install custom made single purpose solar panel davits that will not hang out as far as a pair of actual dinghy davits.

I have a ketch so I'm still toying around with adapting my mizzen boom to provide double duty as a crane for hoisting the outboard or even a MOB from the waterline to the deck using the winch on the mizzen mast.

Pete

[INCOMMUNICADO]

Jim, I found this interesting . Atlantictowers.com  Allen

[jpendoley]

Thanks everyone for your thoughtful replays. Am leaning towards the Kato favors, the Island model with 300 pounds capacity per arm.
Still trying to determine how to add the panels and keep them as far inboard as possible. Tropicbird is a sloop so no mizzen to contend with.
Have read previous threads about davits , pros and cons and don't plan on blue water use at this time. If I do eventually head offshore dingy will be deflated and lashed on deck.
As for the merits of towing? I have lost a dingy towing in a coastal storm and had another swamp and become a sea anchor , so davits are the chosen course with deck lashing for offshore work.

Regarding panels, the Atlantictowers option looks pretty solid if I can't get the panels on davits. Does anyone have experience with them? I cod still get davits in addition to the tower

[S/V Deo Volente]

I found a picture showing my davits. Getting on and off isn't too difficult using the backstay as a handhold and one step on the ladder. Solar Panels would certainly make that more difficult.

[Della and Dave]

I'm curious how you decided on two 140 watt panels. I know refrigerators can be power pigs, but it's close at 280 W total to what Wayne and Dana on Journey said was a good setup.  Sailing Seadragon on the forum under boat web sites has an an energy audit spread sheet. He puts refrigerator draw at 5 amps, but duration depends so much on your ice box, no way to tell how many amp hours per day.  I have been researching the same thing, but since we are in Alaska, the whole solar thing guys a bit different with the crazy sun angles.  We also are moored in a Fjord open to the south, but surrounded by mountains on 3 1/2 sides.  We are hoping to eventually head out to where solar would be a better deal, but would want to do the mods to the boat before cast off, then see if it worked halfway to Hawaii:-).

Journey said that they think that 300 watts with an MPPT controller would be a pretty good setup on Davits, especially with a wind generator on this link.  (There have been out for a few years now, so real experience). http://www.pearson365.com/forum/index.php?topic=25.0.

It seems like swiftibis is selling Power at 630 Watts of solar as well. http://www.pearson365.com/forum/index.php?topic=1322.0.

That makes me think that somewhere between the two would be ideal.  For us maybe a bit more because of the latitude issues unless we want to charge some other way occasionally.  It also seems, from the reading I have done and talking to some solar guys at a seminar on alternative energy, an MPPT controller is the best tech at this point, but individual pannel controllers are coming that would essentially incorporate a controller into each pannel, minimizing the effects of shading.  Maybe eventually each cell would have a printed controller in the silicon, but that's still scifi.  They are already available for grid tie.   

[Dale Tanski]

Perhaps this will be helpful...

I looked into the Forespar Davits, the Nova series that are rated for 350 lbs are a very nice set and are indeed very well made.  The davit set weighs 90 pounds which says a lot for their robust construction. 

For the 365er's out there, I am offering them for $1400 per set.  They list for $1894 and after hunting the internet and the big hitters in marine web sales this price can not be beat.  The only variable would be shipping. I would drop ship them to your location.

Hope this helps.

Dale
Obersheimer Sailor Supply
Buffalo NY
(716) 877-8221

[jpendoley]

Maruska and Della and Dave,
I am going with the Kato davits with solar mount kit. Rated for 600 ponds hoist weight. I like the heavier lift capability and the extend 42" beyond the stern which will give me room for panels with minimal overhang and still allow access to the boarding ladder.
Regarding 280 watts of power, my AB never draws less then 6 amps and sometimes as much as eight. seems to cycle every 10 minutes for three minutes so that 18 minutes of run time in an hour ( call it 30 or .5 hours conservatively).5 hrs x 7 amps/hr=3.5 Amps per hour x24 hours = 84 Amp hours to run the fridge every day.

At best each 140 watt panel puts out 8 amps under ideal conditions. I live in New England so figure 10 hours of usable light-thats only 80 Amps of power from one panel. Barely breaking even on an ideal day.

Eventually, I will rebuild the box-but for now I need a working fridge that does not require daily running the engine.

[PeteW]

My home brew  reefer comes on 5 to 6 times per day. It will run for about 2 hours each time. It consumes 64 AH per day with 32 AH of that when the solar is offline during the 14 hours I call night. I don't have any extra insulation. I think the 10 cu ft box works fine as is.  It maintains 3-8 degrees Celsius 5" below the lid.

I've posted an Excel  spreadsheet which is a first draft at a power budget. With Reefer, NAV equipment Radio and lights  I use 148 AH per day with 91 Ah of that discharging the batteries at night. With 2 100AH batteries they are discharged by 45%. (no margin there)

During the 10 hours of the day the 240 watt solar panels will deliver 16 amps at 13.8V . Based on Avg daytime load there are 11.6 amps left over to charge the batteries and replace the 91 AH used at night. The spread sheets shows a margin of 25 AH charging capacity during the 10 hours of solar panel daylight.

I ran the spread sheet with 300 AH of battery capacity and my discharge dropped to 30%. I then reduced the solar panel to 200 watts and my margin went negative to -1.5 AH.

So I think 240 watts of solar and 300 AH of battery is a good baseline configuration. Naturally this provides little margin for TV's and computers and Radar or autopilot. Running that stuff during the day when there is left over current to spare from the solar panels and shedding night time load is a way to manage this budget.

I can now clearly see the advantage of supplemental wind generation versus needing to add more solar and  more batteries simply to make it though the night.

Note to Administrator: upload folder is full.

Pete

[Dale Tanski]

The engineer in me does some numbers you see... 300 lbs of load 42" out on the end of the davit will transmit a resultant loading of 1050 lbs off of the stern rail, each. That moment arm is in reality pulling on the stern rail perpendicular to the deck with a combined loading of 2100 lbs.  I am not so sure a 365 stern rail will take that load?

What say you?

Just a thought.

Dale

[jpendoley]

Pete, great post, thank you! I suspect that the box is poorly insulated (as most Pearsons seem to have been of that era), but no time for excavation on that front. If I do re-insulate, I'll take pictures so the group will know what they are working with if they decide to re-insulate. I've rebuilt a pearson box before and the improvement was dramatic.
Jim