Holes had been manufactured in the ribs by large hydraulic punches so that the steel plates, formed in enormous rolling mills, could be riveted to them. Then the forming of the standard shape of the ship started. The keel was set on wooden blocks, and from it the stem, stern and ribs were set up, so that at this stage the ship looked like a huge metal basket. Then the plates were riveted in place, and caulked, not with oakum, as in the days of sail, but by the sharp edges of the plates getting turned in with a chisel so that the whole hull was watertight and sleek. The steel decks had been caulked far too, and painted, prior to getting laid with teak planks. When the shell was completed, then the new ship was introduced.