whisky plank
n.— «There is, fortunately, a ritual that differs from this wasteful ceremony that is known as the placing of the whisky plank. When the last plank is in place on the hull of a ship which is being built, work is stopped briefly and all hands are poured a tot of whisky to celebrate.» —“Ebb and Flow” by Walter Muhonen Los Angeles Times May 1, 1960. (source: Double-Tongued Dictionary)