Turning Hull
tony o'connor
Undercoating completed so it's finally time to turn her over. I began by making a frame to roll the hull in, the pieces below are cut to fit close to the hull and with equal radius, they will be on the far side away from the lifting tackle.
The two radiused frames in position, they are left clear of the hull, I used wooden wedges with padding between the frames and hull.
On the other side the frames are left square, the two sides are connected across the keel with a piece of 4x2, the frames are bolted to the building frames under the boat. Then each ring frame is bolted to a lenght of steel tube seen at the base with an eyebolt to take the lifting strap. Finally lenghts of wood are fixed between both ringframes to prevent them from splaying.
The next step is to lift the hull far enough to dismantle the building jig, the bolts connecting the bulkheads to the building frames are removed except on the two frames holding the ring frames.
Building jig dismantled and removed.
Before lifting the hull straps are passed under the steel tubes and over the hull just in case there is any movement, the hull is taken off the plastic boxes that held her clear of the jig and lowered to the ground, then the lift begins.
Balance point, when I lifted the hull to this point the weight of the keel started to roll the hull over, the rope in front of my legs is taken around the leg of my (fixed) workbench and then up to the lifting tackle preventing the hull from rolling further, the next part of the turn is controlled with this rope , by easing the rope the hull continues to roll to the right, this was quite a nerve wracking operation as there was a lot of strain on the rope, without a turn around the leg of the bench I could not have controlled the operation. It is interesting to note how far over the hull could roll and still self right from looking at this picture, of course a finished boat would have the weight of roof, deck, and spars which would affect the centre of gravity but this would be counter acted by the bouyancy of the decks and cabin so it is difficult to quantify exactly but I feel sure that the righting moment from a complete knockdown would be considerable.
When the hull is over far enough the boat is lowered with the lifting gear.
Finally we are back down and I can relax.
Frames removed and I get my first look at the hull.