I considered that, if the lifeboat fully manned were launched into the roughest seas, or off the deck of a vessel, it would, even if turned on its back, immediately right itself, without any of the crew being disturbed from their positions, to which they were to have been strapped.
It happened that at this time (the summer of 1850) his Grace the late Duke of Northumberland, who had always taken a deep interest in the Lifeboat Institution, offered a prize of one hundred guineas for the best model and design of such a craft; so I determined to complete my plans and make a working model of my lifeboat.

I came to the conclusion that the cylindrico-conical form, with the frames to be carried completely round and forming beams as well, and the two screws, one at each end, worked off the same power, by which one or other of them would always be immersed, were worth registering in the Patent Office.

I therefore entered a caveat there; and continued working at my model in the evenings.

I first made a wooden block model, on the scale of an inch to the foot.

I had some difficulty in procuring sheets of copper thin enough, so that the model should draw only the correct amount of water; but at last I succeeded, through finding the man at Newcastle who had supplied my father with copper plates for his early road locomotive.
The model was only 32 inches in length, and 8 inches in beam; and in order to fix all the internal fittings, of tanks, seats, crank handles, and pulleys, I had first to fit the shell plating, and then, by finally securing one strake of plates on, and then another, after all inside was complete, I at last finished for good the last outside plate.