Author Topic: Ocean Series Davit and/or Arch - ideas  (Read 2551 times)

Jeffatoms

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Ocean Series Davit and/or Arch - ideas
« on: June 12 2020, 19:06 »
Hello,

We are contemplating adding davits or an arch with dinghy lifting capability to our 1998 Ocean Series, SV Zephyrus.  Currently we are in the planning stages. As such, it makes perfect sense to check and see if others in our Bavaria community with the same or similar cockpit, deck, transom arrangement have advice including practical wisdom gained by installing or simply acquiring a similar set-up on your Ocean Series 38/30/42 Bavaria Sailboat.  As we are in the business of marine parts fabrication, we are not opposed to custom, if that is warranted.  All comments and guidance are welcome.

Thanks in advance!
Jeff & Sue
SV Zephyrus
1998 Ocean 38

Markus

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Re: Ocean Series Davit and/or Arch - ideas
« Reply #1 on: June 13 2020, 20:26 »
I've got a fairly flimsy arch standing on the pushit and separate davids on deck of Ocean 40. Not a setup I would recommend: the davids on deck hamper available space and moving through stern.

If I was to make a new arch, I would for sure want the davids integrated with the arch as you suggested. It would also be mounted on the toerail and not on the pushpit and it would be made of around 40x2 mm pipe so that it would be strong enough to climb on.

One option would be to have the dinghy lifting as one extra arch, hinged from the lower corners of the arch in such a way. With this setup the dinghy moves aft when lowering and forward when hoisted which would be good. And if the dinghy is not on the arch, nothing is protruding aft. But I have no experience with this type of setup - just a though...

https://i.pinimg.com/originals/a0/ac/08/a0ac0842bcc668671d8fb79af8e810af.jpg


Salty

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Re: Ocean Series Davit and/or Arch - ideas
« Reply #2 on: June 14 2020, 00:10 »
.
If I was to make a new arch, I would for sure want the davids integrated with the arch as you suggested. It would also be mounted on the toerail and not on the pushpit and it would be made of around 40x2 mm pipe so that it would be strong enough to climb on.

One option would be to have the dinghy lifting as one extra arch, hinged from the lower corners of the arch in such a way. With this setup the dinghy moves aft when lowering and forward when hoisted which would be good. And if the dinghy is not on the arch, nothing is protruding aft. But I have no experience with this type of setup - just a though...

https://i.pinimg.com/originals/a0/ac/08/a0ac0842bcc668671d8fb79af8e810af.jpg

I’ve fitted an arch partly on the transom and partly on the deck outside of the cockpit area of my B36(2002) using the 40 x 2mm stainless tube, and can confirm it is strong enough for me to climb up the sides, though I have not attempted to go across the top. It is great for mounting PV panels and also my AIS transmitting and receiving aerial. I have toyed with the idea of being able to hoist my dinghy onto it and have tried just fitting a couple of pulley blocks to the aft rail that lift the dinghy sideways up and out of the water. But this set up blocks my view astern which I’m not happy about such that I don’t use it. However the system shown in your picture at the above web address looks very interesting as it takes much of the weight of the dInghy away from the arch, transferring it to the hinge arrangement at deck level. I’ll give that some thought as a possible alternative, thanks.

Markus

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Re: Ocean Series Davit and/or Arch - ideas
« Reply #3 on: June 15 2020, 06:49 »
I’ve fitted an arch partly on the transom and partly on the deck outside of the cockpit area of my B36(2002) using the 40 x 2mm stainless tube, and can confirm it is strong enough for me to climb up the sides, though I have not attempted to go across the top. --- However the system shown in your picture at the above web address looks very interesting as it takes much of the weight of the dInghy away from the arch, transferring it to the hinge arrangement at deck level. I’ll give that some thought as a possible alternative, thanks.

Yes, it is a benefit that a part of the load of the dinghy is on the deck and not on the center of the arch. That said, a 2.5 m wide 40x2 mm arch having two horizontal tubes should be able to take a load of 100 kg at the center of the arch, which should be fine for a small dinghy. From my point-of-view, one of the major benefits of the hinged system would be that there's nothing protruding aft of the arch and that the dinghy is naturally lowered down and away from the boat and up and into the boat.


Alphadug

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Re: Ocean Series Davit and/or Arch - ideas
« Reply #4 on: June 16 2020, 16:51 »
Slightly off of this topic. I have a Vision 42 and I toy with the idea of davits. My problem is my dinghy. It's a 12' RIB with a 30HP outboard, I figure it's at least 500 pounds maybe closer to 700. I would have to design the system and reinforce the mounting points. Before I go this far I would need to get 4 extra people to stand at the back of the cockpit to see how the boat likes the extra weight aft. Anyone have thoughts on this or am I crazy to attempt it? At the moment we tow it everywhere just fine.

Thanks,
Doug

Markus

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Re: Ocean Series Davit and/or Arch - ideas
« Reply #5 on: June 17 2020, 09:20 »
Slightly off of this topic. I have a Vision 42 and I toy with the idea of davits. My problem is my dinghy. It's a 12' RIB with a 30HP outboard, I figure it's at least 500 pounds maybe closer to 700. I would have to design the system and reinforce the mounting points. Before I go this far I would need to get 4 extra people to stand at the back of the cockpit to see how the boat likes the extra weight aft. Anyone have thoughts on this or am I crazy to attempt it? At the moment we tow it everywhere just fine.

Well, the arch would need to be much more robust than on a boat of this size normally, making it also heavier. And you'd need to very carefully consider the mounting points as you mentioned, taking into account side-loads when sailing, etc.

To me it sounds so much easier to just downsize the dinghy and especially the outboard, but I suppose you really prefer the big dinghy and outboard as you have acquired them... :)

Symphony

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Re: Ocean Series Davit and/or Arch - ideas
« Reply #6 on: June 17 2020, 10:44 »
That really is a huge dinghy and probably beyond a traditional set of davits. The maximum safe lift of most davits such as Simpson is 250kgs before you get into superyacht style hydraulics where the maximum is 400kgs.

250kgs will comfortably take a RIB of around 2.6m and outboard of 10hp which is much more appropriate for this size boat.

Alphadug

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Re: Ocean Series Davit and/or Arch - ideas
« Reply #7 on: June 17 2020, 18:22 »
I agree on the size of our dinghy. Big. Since we only do coastal cruising in the Salish Sea we don't need to stow a dinghy for a long haul, 6 hours at most generally. We have a smaller roll-up with 4 horse that came with the boat, it's in the basement at home. We like to anchor for a few days or until we run out of water or holding tank room and explore by dinghy. We're never more than 15 miles from civilization in the form of fuel and water and sometimes we need some groceries or want to go to a restaurant and don't want to spend all day getting there and back so a 20+ knot spin in the dinghy does the trick. Also, there is no radio or cell coverage in some areas so you need to go 5-10 miles to get a weather report. And it's fun to go for a run at more than 7 Kts now and again:) The davit thing is really only an engineering exercise as towing the dinghy doesn't slow us down much and as sailors we're never in that much of a hurry to get somewhere.

Doug

Jeffatoms

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Re: Ocean Series Davit and/or Arch - ideas
« Reply #8 on: June 30 2020, 15:34 »
I digress a bit but the davit thing has more to do with where do we store the dink when we arent out cruising?  I agree that it is easy to tow, but our homeport marina is tight on space, has no dinghy dock and though we have room fore and aft, the neighbor's boat is a scant 24 inches from ours and there is no easy way to move the dingy forward/aft, once berthed.  The other concerns are engine theft and growth on the dinghy when left in the Salish Sauce.  A decent davit system would solve all three.