Mclaren Clockwork Submarines

Several of my boats are compound curve hulls, the construction of this type of hull is relatively easy, all you need is a sandbag and a hammer. The two top pics show the same piece of tin, the left is roughed out then rolled on the right,it takes about half an hour to do. For some reason people think compound curves require vast amounts of algebra and complex equations? this is simply not the case. Once formed the Half cigar shapes can be cut and shut into the required hull form.