Controlling a swinging dinghy crane ?

I love that we no longer have to hoist our dinghy up the mast to lift it over the side to launch or retrieve, but the crane offers its own challenges.



The dinghy and motor aren't huge but controlling the ~200 pounds at the end of the crane in big swells certainly is exciting. It wants to play wrecking ball and there is no brake preventing the crane from swinging around.

Once the dinghy is down far enough to use controlling lines from deck the excitement dies down, but while the dinghy is at the top it is pretty much like a rodeo. The fact that there are no rails or lifelines on the top deck make it more fun.

I have looked for some way for one person on the top deck controlling the swinging while also running the winch but so far I haven't come up with any ingenious answers. Are there any tricks I might be missing or are there brake systems that can be retrofitted to this kind of crane ?

Thanks,



-Sven

We get a bit lowering and lifting the dinghy but not much, but we always have it be a two person job.

On lowering we throw the bow line over and the person in the cockpit catches it. The person on the boat deck operating the davit holds onto the stern line. We then lower it keeping both lines taut once the dinghy is parallel to the boat. It doesn't stop it bouncing a bit in a swell and now and then it might tug around a bit, but not a big problem the way we do it.

menzies said:

We get a bit lowering and lifting the dinghy but not much, but we always have it be a two person job.

On lowering we throw the bow line over and the person in the cockpit catches it. The person on the boat deck operating the davit holds onto the stern line. We then lower it keeping both lines taut once the dinghy is parallel to the boat. It doesn't stop it bouncing a bit in a swell and now and then it might tug around a bit, but not a big problem the way we do it.

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Yup. Pretty much the way we do it, too.

I’ve learned that I can control the swinging by having BOTH the bow line and the stern line in my left hand and the crane remote in my right hand. If the dink starts to swing, I just step backward, take in tension on the bow and stern line and the swinging stops.
Hope that helps��

Taras said:

I’ve learned that I can control the swinging by having BOTH the bow line and the stern line in my left hand and the crane remote in my right hand. If the dink starts to swing, I just step backward, take in tension on the bow and stern line and the swinging stops.
Hope that helps��

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Thanks.

Is there a stop to keep the crane from following you in its swing as you back up ? As far as I can tell our crane will do a 360 if it feels like it.

It sure would be nice if one could retrofit a hand-cranked worm-gear that would let you swing the crane around under some control by cranking the gear.

Thanks again.



-Sven

Trawler_traveler said:

Thanks.

Is there a stop to keep the crane from following you in its swing as you back up ? As far as I can tell our crane will do a 360 if it feels like it.

It sure would be nice if one could retrofit a hand-cranked worm-gear that would let you swing the crane around under some control by cranking the gear.

Thanks again.



-Sven

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That's probably the difference between your crane set up and our davit. Once the dinghy is outboard of the boat the davit pretty much stays there. Your lighter crane probably moves more.

Is there any way of having a pin placed in the bottom deck plate of the crane once you have it swung that would prevent it swinging back?

My boat is usually pretty trim port to starboard. Usually when I push the dinghy out the stern and to starboard, the boat heals to starboard. So the crane can swim some, but prefers to point to starboard. Controlling the dinghy is a matter of keeping the bow from swimming out to far with a bow line. It takes some practice, but I'm always launching solo, so there isn't much choice. Retrieval is pretty much the same in reverse. Pretty easy to control the crane by pulling the dinghy around by the bow.

Ted

Our trawler has a mast and boom ("jib" crane) and swinging the dinghy outboard from the cabin roof or bringing her back can be exactly as you describe...quite an exercise in swinging! If there's any swell or wind I have SabreWife hold onto a control line down in the cockpit pulling the RIB against the side of the cabin to help keep it under control.

If only I had three arms!

I tie a 1/2" line to the hole at the top of the davit and tie the other end to a folding ring on the boat deck. I adjust the line so the davit can only rotates 60 degrees out the side of the boat. The weight of the dinghy puts tension on the line, keeping the davit from swinging. The line is left attached all summer for ease of launching.

As the dinghy is lowered, I control it's orientation with my hand or foot. My wife is in the cockpit, steadying the dinghy with her hand. The roof overhead provides protection during the assist and she doesn't put her hand under the dinghy.

Process is reversed for retrieval. The line is used to pull the dinghy in until the bow can be pulled.

Our 12' fiberglass tender weighs around 500# so it does'nt swing around too much. The 12' sailboat weighs 110 pounds and the wind can swing it around in addition to seas. We anchor in smaller protected harbors so there isn't much fetch for waves to grow.

menzies said:

Is there any way of having a pin placed in the bottom deck plate of the crane once you have it swung that would prevent it swinging back?

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That's certainly a possibility that we should look into. Mayb a second one when the crane is in the normal stow position too.

Thanks.



-Sven

menzies said:

Is there any way of having a pin placed in the bottom deck plate of the crane once you have it swung that would prevent it swinging back?

Click to expand...

I have a hole in the davit base for a pin to secure the arm from swinging. The 1/4" pin that I inserted to prevent davit rotation was bent while lowering the dinghy.

The line described in #9 above, prevents the arm from swinging.

I also use it to swing the dinghy out slowly. As the dinghy swings out, the boat heels and causes the dinghy to swing out quickly.

The line keeps the davit arm from swinging out all the way and stops it from going further than 60 degrees. That makes it easier to bring the dinghy in during retrieval.