Launching the "Musashi" also presented problems. The ship's thick launch platform, made of nine Douglas fir planks bolted together, took two years to assemble (from keel-laying in March 1938) because of the difficulty in drilling perfectly straight bolt holes through 4m of fresh timber. The problem of slowing and stopping the massive hull once inside the narrow Nagasaki Harbour was met by attaching of heavy chains on both sides of the hull to create dragging resistance in the water. The launch was concealed by means including a citywide air-raid drill staged on the launch day to keep people inside their homes. "Musashi" was launched on 1 November 1940, coming to a stop only in excess of the hull's expected travel distance across the harbour. The entry of such a large mass into the water caused a wave, which swept the harbour and local rivers, flooding homes and capsizing small fishing boats. "Musashi" was fitted out at nearby Sasebo, with Captain Kaoru Arima assigned as her commanding officer.