Torpedo bulkhead, a type of armor designed to keep a ship afloat even if the hull is struck by a shell or by a torpedo
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Bulkhead line, a method of coastal demarcation used within a legal system
A few airlines have gone to branding exit row seats as a premium economy product - on Virgin America's A320, the exit rows (as well as bulkhead seats) are considered "Main Cabin Select" where meals, alcohol, pay-per-view movies and a higher baggage allowance are all included.