An update on Tuanella3 - the pontoon.

As previously mentioned the stability of Tuanella 3 was profoundly out of kilter and she road so high on the water as a finger tip could push her to one side or another - this despite a massive lead keel and sacks of aggregate against its sole.

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                 This picture shows the water mark some 7 or so inches from the bottom.

                                            She is really just sitting almost on knife edge.

The hull was of 2mm marine aluminium  and this was patently too light. Although the cabin is of wood, perspex and aluminium section it was distant enough from the water line to aid toppling the craft.
Having decided at this stage to preserve the engine arrangement I set out to counter the stability with two outriggers. There were to be two but just making one for the moment is all I can manage. I have tried to arrange it so that it will fold up against the port side to aid transport and so, hopefully, all I shall have to do it lower it in the water and let the hinge and strut arrangement hold the pontoon in place. It is close to T3's hull but of a weight and buoyancy that should steady her.

Nothing of the gunwale fittings are attached here to T3 but the general idea of how she will lie is shown.

The general heftiness of the fabricated hinges and slides can be seen in the following.

Just a couple things of note about the fittings above: the double offset hinge rotates both on the hull and the pontoon.  This is only at the stern end. Forward the hinge there rotates only on the hull.The attachment of both hinges is well above the envisage new water line. Not knowing quite where the pontoon will find its level the flexibility offered by the hinges will hopefully accommodate this. I expect the maximum displacement or draft of the pontoon to be about two inches in calm water.
There is a worry that when the craft is launched the  weight of the pontoon will not be enough to offset the possibility of a tumble to starboard if there is rough water and wind from port side. I guess wearing a life jacket will be important.