Nesting 2 Part Dingy (that uses Mirror Dingy sails and spars)

[ianabc]

I have drawn up the hull for a nesting dingy 11 feet long that uses Mirror Dingy parts.

I am sure that this not original but it will work for me on foredeck of our 37 foot boat, or even forward of the main hatch leaving room for a hard case liferaft between the mast and the hatch.

I'm open to free sharing of the design after it's finished.

WHAT (sensible) DETAILS would you in include...

Stern part, 7 feet long X 4 feet wide, bow section 4 feet wide X 3.7 feet

Probably build thin scrap ply full size model, then cut 3mm aluminium sheet (5000 series so called marine al.) and have it welded up. Considering hauling the 2 parts to the powder coating shop and have the whole dingy powder coated white for that yacht look!

Have already designed locks which are simply bulkhead section overlapping second bulkhead and clamping in 2 places near top. No machining required.


Ideas please...

 

[Kilter]

Depending where you are going don't make it too smart. That way it's less likely to go missing from the dinghy dock.

 

[sarabande]

There was a similar project in PBO some years ago.

What about built in buoyancy, or a RIB type collar to help the liferaft function. Also a tent for protection from the elements, lockable storage for the emergency kit, orange dayglo rather than white, reflective tape on the mast.

Like the idea, but I think it will cramp the foredeck a bit, based on our own experience with a wide 35ftr.

Post the piccies in due course !

 

[Bajansailor]

I have also drawn up a two part nesting dinghy (11'4" x 4'4") which I am in the process of building.

It has two chines each side, and pram shaped bow & stern transoms, and it should stow in 6' of length. I am building it from fibreglass sheets laminated up on a flat mould surface, and then glassing the joints. The sheets are made from a CSM/WR/CSM sandwich.

The joining method will be via a pair of ring frames 4" deep rather than using bulkheads - OK, this means that I need to have a good water-tight gasket between the frames, but it also means that I can stow the nested dinghy upside down over the companionway hatch, and it can function as a dodger (it will have adequate headroom for accessing the companionway because of the ring frames).

I am just going to use simple hex-head bolts with wing nuts (and fender washers each side) for securing the ring frames together.

If you build yours from 3mm ally sheet it will be massively strong - and a fair bit heavier than a GRP hull of the same thickness.
(A typical single skin GRP laminate has an SG of approx 1.3, while aluminium has an SG of approx 2.8).

You could have a fairly large buoyancy compartment in the forward section (similar in some ways to a Mirror dinghy), and you can make small buoyancy chambers in the stern quarters of the aft section (ie the space 'eft over' when the bow section is nested in it). A removable longitudinal centreline bench seat works well with nesting dinks.

 

[Blueboatman]

I think thats a great idea...
Just got back from a sailing holiday where oarless,outboard powered inflatables ruled (expensively,noisily and vulnerably).With these minor niggles fresh in my mind,hows about....

Welding 20mm round ally tube around the top?
You can then fit either foam insulation over this,or attach a cover over all.
Would you add horizontal gussets at all corneres with cut outs to act as handholds and somewhere to thread the security chain?
With all that,maybe a couple of eyebolts welded for hoisting...
...And a skeg with a wheel aft.
Lockable thwart boxes with block foam flotation.
Two eyes up front for towing
The proportions sound good...Stability is affected more by beam than by length,and increases,if I remember rightly,as a square of beam is it ?
I like the idea of getting it right in ply first..
Have fun.
ps You might be able to get some rocker on the keel and both reduce and rake the pram bow so it wont slam and dig in or stop when going into choppy waves ?

 

[Talbot]

rather than a single skeg with a wheel, it would be better to use two and put wheels on both so that it is more stable.

You also need some sacrificial wear strips so that when you beach onto a slipway, it doesnt scratch up your nice powder coating.

 

[tangomoon]

An idea I read was to put a wheel in the bow and make apertures in the stern to insert the oars. This enables you to use it as a wheel-barrow. Definitely make it smart.

 

[graham]

no experience of building metal dinghys but 3mm seems very thick. The odd one I have seen seem to be more like 1mm thick.

 

[graham]

Ignore my last post.(too latefor it to be deleted).I just found a website for aluminium dinghy plans.The 3.8 m one uses 3 mm plate. alluminium dinghy plan

 

[MichaelHomsany]

Hi,

Although no plans are shown, you might want to look at Rin Tin Twin .

There is a modest bit of pride in it. It used 2.5mm for the bottom plates, 2mm for the top plates. 3 years now in continuous use in the Pacific (read coral!) and going fine.

Best regards,
Michael