OUTBOARD ON RIB WHILE CRUISING

[penpal]

I have a rib (2.7 m) on davits, it is over 10 years old now so abit passed it's best. We have a Honda 4hp 4 stroke, which we store separatley on the boat. the trouble we have is that the outboard is too heavy to lower from the aft deck or sides and hand to my wife to secure onto the rib. I asked a local chandlery about a 2.4hp, but he thought it would be underpowered. The only other thing i can think of is to leave the outboard on the rib while hanging from the davits. The davits are Simpsons, they look sturdy enough, but you seldom see a dinghy or rib with motor on a cruiser while travelling, so I wondered what others do.

 

[hlb]

There should be a plate on the davits, to tell you what it can lift.

Mine are fine with a 2.6 dinghy and 4hp two stroke outboard on the back.

 

[penpal]

As far as i can work out the rib weighs 36kg and the engine 25kg, when I looked on the Simpson web site the minimum weight capacity was 150kg. I expect the cable will strectch a bit, but as long as bumpy seas do not make the cable unwind I should be okay.

 

[gjgm]

I ve got a little 2.4m and a 2 st 3.3. It gets you there, but when we stuck down in Dartmouth last year, I noticed that crossing the river with wind and tide was a slow process.
Its fine in unchallenging conditions, and I guess it just managed in that one, but any less I m not sure where we would have landed!

 

[PCUK]

I've got a 3.5 metre rigid dory and 25hp on Whittall davits.
Total weight 160kg, no problems and well within the weight capacity.
Remember your davit capacity is normal working load, breaking load will probably be four or five times that.

 

[hlb]

A guy here a few years ago said that.

Then he came back to report about the cracks in his transom.

 

[oceandrive]

As said above check the plate on the davits to make sure that they are large enough to take the weight of the outboard. what we do is create a couple of spring lines for the tender to stop any swinging " Line from the stern of the tender to the Base of the davit over the bow of the tender and another from the bow of the tender to the Base of the davit over the stern" This takes all the sideways swing out of the tender and so less twisting effect on the davits. I slightly twisted a davit during a passage across the Bay of Lions and by doing this we managed to continue with a weakened davit and no further damage. you will note immediatly that the tender seems to move with the boat rather than swinging from side to side on its davits. Keeps all the forses in one direction i.e up and down. Hope this helps wish I could draw it for you.

 

[Nick_H]

It'll be fine. I've always left the outboard on when the tender has been on davits. Do the davits have extending arms? It's much better if they do, as you can pull the tender tight against the davits, so it can't swing at all.

 

[hlb]

With a couple of blocks of wood on the davits, it works even better.

 

[blueglass]

yes we also have 2.6 dinghy with 3.5 tohatsu which live on the davits while we are on board. o/b is removed below for security when we go home. important as said eaelier to take as much swing out of it as you can, and have the dinghy's transom lower than the bows with the bung out otherwise the extra weight of rain/spray in there can be significant in bad weather.

 

[RogerRat]

As said above, should be fine after checking weight spec of davits. Have you a 2.7 rib or air-deck? A rib could be twice the weight but still ok.

I had a 2.7 air Quicksilver air-deck with a 10Hp on my Phantom 38 and left the engine on no problem.

BUT, don't leave it to the hoist cables alone! Get some tie down ratchet webbing straps to secure the dinghy to the davits while underway, so effectively, you will be tying the dinghy up to the davits and you'll have no swing at all. Once strapped up, you can then release some tension off the cables.

 

[penpal]

Thanks erveryone, I will do a test run at the weekend and spring it as suggested

 

[Andrew_Fanner]

The davits lift it fine, but I dont trust the ratchet. Found that out the hard way and nearly broke my writs in the process.

O/b off and stowed now. Just careful putting it on/taking it off.

 

[miket]

I would be more concerned about the davit mounting points on the deck/ hull than the davit itself.
The original davits supplied with Freemans were never meant to handle the weight of your combined RIB/ outboard so would hope that additional material has been introduced to take the extra load on your replacement Simpson davits.
I have seen a number of boats fitted with a lightweight s/s davit on one corner of the stern, above a rail or transom mounted o/b bracket. The o/b can then be lowered to the dinghy with relative ease.

 

[DAKA]

If I am just going a few miles to the beach then I leave the outboard on the tender and I agree it is very easy.

If I am going offshore I always remove the OB.

I have seen davitts ripped off boats that have been well within spec.

My current OB is a 9.8 HP Tohatsu, bought for the lightness.
My other OB is a 4 HP mariner.
Both are stowed on board.

My last boat had a bracket on the stern where the 4 HP lived until needed untill needed.
That worked very well.

 

[penpal]

I had large steel mountings made so the davits sit nice and square, but it is a lot of weight to be swinging out there for so little use. It is more a case that it is a feel safe for my wife to know we can easily put the rib down and escape!!