Dinghy mounting on Swim platform - Chocks...?

[Hurricane]

Sorry
I was going to post some photos of the fittings that I've got.
Better late than never
I think they are self explanatory
JFM's point about waterproofing for a non Ho/Lo bathing platform is covered with these fittings.
A S/S capped tube has been welded over the underside of the hole

 

[lanerboy]

great pics mike thanks for sharing gives me a better idea and something to show the fabricator of what I want

thanks

 

[jfm]

But mike those do not have keyholes and so they only work in some applications. To have waterproof keyholes you have to weld a little box on the underside of the plate

 

[RogerRat]

great pics mike thanks for sharing gives me a better idea and something to show the fabricator of what I want

thanks

Yep, from me too. I like the circular version over square as easier to make flush with the teak. I don't have a Hi/Lo platform but the water proofing is important as the platform is a sealed cavity. I don't think I'll need keyholes either as the weight of chock should hold it.

Mike, what will you use for anchor points for strapping down the ski to?

 

[Hurricane]

Mike, what will you use for anchor points for strapping down the ski to?

The same circular plate/disc but with one of these welded to the bottom (M12)
Instead of the capped tube

And one of these screwed in whenever you need it

I can get to the underside of our bathing platform so I'm going to use countersunk bolts and extra thread nuts (nilocks) with penny washers on the underside.
I also use ratchet webbing to tie the dinghy down.
That should hold well.

 

[RogerRat]

Mounted dinghy and Chocks - Finally!

Apologies for taking so long but after all the constructive comments and replies to my original post - Thank you all BTW.

I have now mounted my dinghy in the last couple of weeks and made up rope strops with 12mm 3 ply and snap shackles to hoist using the passerelle as a remote control crane. The full load is way under capacity as the dinghy and 8 Hp Yamaha weigh in at about 85 Kgs. combined.

Rear view of he dinghy in place, held down by self recoiling ratchet straps. (steel tape measure style)

The Chocks:
Machined from 50mm White Nylon (type) blocks, courtesy of Kelvin at Pierce Engineering from cardboard templates. Not bad match but he also made up some alloy ones to make sure first. These are screwed down into blind hole captive M10 dome nuts welded under 60mm stainless circular plates routed to be flush on the teak surface with a 3mm surround of black 'Sika flex'.

Lowering the dinghy is very easy now as the remote control can be held in one hand and guidance into the chocks be assisted with the other. You can see how flat the rear of the hull is under the outboard, that along with small 'Dolephins' on the cavitation plate help the 270 'Cabrio' Rib jump onto the plane with only half throttle. Max's out over 20 knots. Nice, but not silly power to weight ratio.

This one shows my 12mm rope bridal with 6mm sliding ring snap shackled onto standard transom mounts. As the Azimut46 has twin transom doors, I wanted to get a dinghy small enough to leave good access through them both. The folding transom gate on the rear of the 'Cabrio' 270 allows me to hinge the outboard way over the top and into the dinghy. As you can see, even before I fit the over cover, there is no prop or skeg protruding into the walkway.

Not bad eh? :encouragement:

RR.

 

[rafiki_]

Looks a proper job RR, nicely done. The twin transom gate is a real benefit on the Azi's, as it gives options for mooring. Our a Ribeye 260 fits nicely on the platform, even on our smaller 39.

 

[michaf]

RR, from experience strapping around the tube is not as good as strapping hull anchor points. When the temp goes down the tubes get softer and the straps get loose. If a tube is loosing pressure same thing but worse. I have now finally after 3 years got the right combination, we've had really bad crossings and the tender didn't move an inch. Here's a pic, our tender is much heavier, so I think you could get way with 4 straps (we have 5). The blue dots are the attachement point on the mother ship, the red ones on the tender. Just did that quickly so if you ant more info...

 

[rafiki_]

RR, from experience strapping around the tube is not as good as strapping hull anchor points. When the temp goes down the tubes get softer and the straps get loose. If a tube is loosing pressure same thing but worse. I have now finally after 3 years got the right combination, we've had really bad crossings and the tender didn't move an inch. Here's a pic, our tender is much heavier, so I think you could get way with 4 straps (we have 5). The blue dots are the attachement point on the mother ship, the red ones on the tender. Just did that quickly so if you ant more info...

View attachment 42859

Nice tender! I strap around the tubes like RR, and yes the tubes lose a bit of pressure over the winter, but I don't take the boat out without ensuring all secure.

 

[michaf]

If it works for you it's fine! If it doesn't, strap it the way I did. Our crossing can be rough I guess (3m swell + 30 knots wind), which makes the strapping a fair bit crucial :disgust:

 

[RogerRat]

If it works for you it's fine! If it doesn't, strap it the way I did. Our crossing can be rough I guess (3m swell + 30 knots wind), which makes the strapping a fair bit crucial :disgust:

Thanks for that, I see what you mean. The mounting for the dinghy is really only for the summer months tho. During the winter, the outboard will be stored safely warm and dry in my garage and the dinghy will deflated and stored up on the flybridge.

If I was planning heavy crossings in 6-7 winds then I would take your sound advice.

Thanks,
RR

 

[MapisM]

The folding transom gate on the rear of the 'Cabrio' 270 allows me to hinge the outboard way over the top and into the dinghy.

I had not seen that yet. Clever idea, though I guess only good for small O/Bs? What's the weight/power limit?
Very nice installation overall, anyway. Congrats! :encouragement:

 

[RogerRat]

I had not seen that yet. Clever idea, though I guess only good for small O/Bs? What's the weight/power limit?
Very nice installation overall, anyway. Congrats! :encouragement:

Thanks MM.
I can see why you had that impression as my dinghy and O/B are small. I think the manual lifting version would be fine up to 15 Hp on 3.5 metre models.

The larger ones go to 5metres. If you look at this link to BHG Marine there's a video of the power tilt version showing a 40Hp being power stowed. At the show they had this operating on a stealth remote control in the pocket.

http://www.bhg-marine.co.uk/ribs/cabrio-ribs/cabrio-380-ch

There is no reason why they couldn't go to larger really, the principle is great. The drive from the outboard is cantilevered, thereby increasing the load that seals the transom door.:encouragement:

RR