Now that the shelter has been completed, we can commence preparing the site for the build. The two hulls are to be built concurrently upside down on ladder frames  called strongbacks – in nautical terms. The stongbacks keep all the elements of the hulls plumb and straight, until they are glued and screwed and self supporting. Building the strongbacks are next on our to-do list and they need to be straight, level and strong. After the hulls are completed, we will have a “turning-over” day, when we gather as many willing hands as we can to flip the hulls right side over for final assembly. Today we are preparing in advance for turn-over day, by building two concrete bearers to accept the keels of the upturned hulls. The strongbacks will be built around them. We used a laser level to ensure the bearers are plumb and level as the ground of our site is quite uneven.