Rigging on davits

[psneeld]

Originally Posted by Pack Mule

Hmm I have a small sailboat winch , it’s not self tailing and I’m not sure I could mount it without doing some welding on the davits. Do you think the one winch would be enough? Would it just need two blocks?

in the middle with the two leads in different directions will work coming up...but a non electric power both ways might not work.


if the lift isn't too high, then one side at a time might work....winch mounted in the middle.....no necessarily welded.

[Ex Sailor]

Originally Posted by Pack Mule

Ok this is driving me crazy . Why are these blocks twisting 90 degrees to each other ? I have swivels on each end . Do I need to remove one ? On the side that has the double block at the top the line wants to climb out of the sheave .

I would take out the swivels and shackles and just bolt ( not too tight but tight enough ) the blocks to the Davits.



My .02 CAD

[Pack Mule]

Originally Posted by Ex Sailor

I would take out the swivels and shackles and just bolt ( not too tight but tight enough ) the blocks to the Davits.



My .02 CAD

I’ve removed all the swivels and replace the lines with new. It works much better now but still too much of a lift for my wife and I . Looking to lighten the load now.

[Pack Mule]

These are the blocks I’m looking at for each side. Over kill or about right ? Dinghy weight is about 200 lbs with motor.

[cappy208]

In an earlier post I mentioned the way to reeve the blocks so they don’t twist under both load and no load. It works. But you MUST reeve them correctly.

https://www.harken.com/content.aspx?id=3901

The rule of thumb for blocks is: The larger the sheave diameter is proportional to the lessened friction. And the better quality blocks with better bearings. Sorry. Can’t help with which is quality and which is not.

It’s been 20 years since I had to buy blocks. But definitely Don’t get ones with delrin or nylon bearings. Stainless or bronze bearing/bushing only.

[OldDan1943]

Dont forget to determine, if the blocks will permit raising the small boat properly to its "up" position.
Also, a 6 to 1 block system will take a whole more line than a 4 to 1. You will be using only 2 blocks lifting the boat from the center point???

May I encourage you to look around at existing davit systems.... you may get some better ideas incorporating an electric winch. No need to work up a sweat putting the boat into the water and taking it out of the water.

[cappy208]

Consider weaver davits and only lifting the outboard side. But this only works on swim platform. And as Dan says: You could probably get away with 4 to 1 on the bow, and 6 to 1 on the outboard end. The weight is not exactly divided in half. It’s more like 1/3, 2/3.

[Pack Mule]

Originally Posted by cappy208

Consider weaver davits and only lifting the outboard side. But this only works on swim platform. And as Dan says: You could probably get away with 4 to 1 on the bow, and 6 to 1 on the outboard end. The weight is not exactly divided in half. It’s more like 1/3, 2/3.

We don’t have a swim platform . What we have is working ok and even better since I removed all the swivels. I like the set up I just want to make sure that adding more sheaves is worth the bang for the buck.

[OldDan1943]

Originally Posted by cappy208

Consider weaver davits and only lifting the outboard side. But this only works on swim platform. And as Dan says: You could probably get away with 4 to 1 on the bow, and 6 to 1 on the outboard end. The weight is not exactly divided in half. It’s more like 1/3, 2/3.

If you go with an electric lift, anchor point for and aft, lifting from the center balance point, you can avoid the blocks.
Again, look around the marina and see how some other folks handle this. Ideas and advice are free.
Just how big is your outboard?

[cappy208]

Originally Posted by Pack Mule

We don’t have a swim platform . What we have is working ok and even better since I removed all the swivels. I like the set up I just want to make sure that adding more sheaves is worth the bang for the buck.

Just buy one set. Use it on the stern end. The stern end is heavier. (Much more so with the outboard).

[Pack Mule]

Originally Posted by OldDan1943

If you go with an electric lift, anchor point for and aft, lifting from the center balance point, you can avoid the blocks.
Again, look around the marina and see how some other folks handle this. Ideas and advice are free.
Just how big is your outboard?

This is the outboard . I believe I’m the only one in the marina with a dinghy . Mostly houseboat dock queens. Here is the motor 2.5 hp Lehr

[OldDan1943]

Originally Posted by Pack Mule

This is the outboard . I believe I’m the only one in the marina with a dinghy . Mostly houseboat dock queens. Here is the motor 2.5 hp Lehr

A 2.5 hp weighs very little. A direct lift is within reason.
The boat weighs far more than the engine.
You must figure out a way to secure the boat when in the "travel position", taking the weight off the lifting mechanism.

[Pack Mule]

Originally Posted by OldDan1943

A 2.5 hp weighs very little. A direct lift is within reason.
The boat weighs far more than the engine.
You must figure out a way to secure the boat when in the "travel position", taking the weight off the lifting mechanism.

The davits have cleats welded on each side for securing the load.

[healhustler]

Marty: My Admiral couldn’t pull the strings for our dinghy davits either, but I didn’t want electric. I finally ended up with twin 900 lb. single speed hand crank trailer winches, using Amsteel grey 5400 lb. single line. Now lifting the dinghy is easy peasy, even with outboard and me in it. The winch bases are drilled for twin 1.5” stainless U-bolts each to grip the bottom davit tube, and both now have sailboat type line locks just in case. Being an old rigger, it took me quite a while to trust single line strength, but eventually I learned, and now I also have the same winch and single line on our rotating dinghy crane for MOB recoveries as well.

[psneeld]

Larry, if you don't mind, where did you get the winches?

[OldDan1943]

Originally Posted by Pack Mule

The davits have cleats welded on each side for securing the load.

Using lines that do not stretch?

[FF]

A winch for each line is fine , with only one winch and cleats you may need to hold the entire weight of the dink, to free the winch.

Simplest is a sailboat set of main sheet blocks that cleat the line automatically.

Crap plastic look , but very functional.

[Pack Mule]

Originally Posted by OldDan1943

Using lines that do not stretch?

I’m sure the line stretches some. 7/16 “ Genoa sheet line.

[Pack Mule]

Originally Posted by FF

A winch for each line is fine , with only one winch and cleats you may need to hold the entire weight of the dink, to free the winch.

Simplest is a sailboat set of main sheet blocks that cleat the line automatically.

Crap plastic look , but very functional.

FF I love the old wood blocks I got from you but we need more power for lifting.

[cafesport]

Try a set of fiddle blocks from a sailboat main sheet or boom Vang. If they don’t work better, you can always use them to lift heavy loads around the boat somewhere. Here is a picture of a set I used to lift a generator into my boat last June.