An Update On What I Am Doing Now.

The failure to appropriately ballast T3 left me with two options. One was to re-ballast: this would mean the opening to the engine well inside the boat would be so close to the waterline that the chance of swamping the boat from inside would be great - dangerous from heeling and rocking except perhaps on a mill pond; removing the engine well and the outboard engine arrangement and replacing it with a hefty inboard well forward where there is maximum buoyancy, and offering up a long shaft along the sole with a standard propeller housing aft would solve this. Thence I could re-ballast to my heart's content.
The other option, which I am now taking, is to deprive the boat of the hefty lead filled aluminium ballasting keel and take the view that she will sit on the water, precariously of course, on her sole.
She will sit like those pond insects - water skaters - barely infringing on the water's surface tension.
Of course she will be impossibly unstable like that and tip immediately.
That is where the outrigger I am building comes in. That, by virtue of its weight and disposition will keep her upright and hopefully, because of its minute draft, and bow form, offer little resistance.
Such a plan means I can keep the present engine well arrangement.
I am doing this before the re-ballasting mentioned above simply to investigate the potential of the option. I am not hopeful of a resplendent outcome but it is a 'suck it and see' situation.
The cumbersomeness of transporting what I'm building pressures me to build in some sort of folding
mechanism for the outrigger to lie against the hull during transit. Such an arrangement required some modelling and I show below some of it, however crude, by way of determining the hinge arrangement. This latter has to accommodate the lines of the hull, the folding of the outrigger to the hull, and fixation to the hull when it has been lowered.

Such hinging I'm sure one can appreciate has to be rather outsize. I show a mock up in mdf  and wood to get a perspective and the clearances right. I propose to make it in aluminium plate, and the welding of  aluminium tubing to it to accommodate stainless steel rod to form the hinge. I have tried to demonstrate on the model the need for the hinge mechanisms to have a universal flexibility to allow for the curving lines of the hull.

This attachment near the water line needs some flex-ability there as the pontoon outrigger has to find a 'best fit' position in relation ot the hull when it is lowered into the water. Stabilisation will come from  a fore and aft spare which will come from the gunwale  to the far side of the pontoon. These too I hope to make adjustable, again to fine tune a 'best fit' when she is in the water. I hope the triangulation provides a stiff enough purchase! 

The shown siting of the hinge below is too central but was just to show the hinge above in place.

It also shows, as does the picture below at the aft end, the added bolstering of the pontoon deck where it will receive the hinges and gunwale struts.

In both a central pillar connects the deck to the bottom and thus hopefully spreading the stresses between it and the hull.

This shows the general lie of the pontoon, fore and aft, and is pretty close to where I expect it to sit against the hull when both are in the water. It looks very long in the above but is only 8 ft and is gently tapered, the width across the nose being shorter than that across her stern. This is to keep her outer side parallel to the T3's lubber line and the inner side pretty much the same with respect to the hull side.