The variety of alloys made use of is magnificent: weathering steel for aging, marine-grade aluminum for weight savings
https://www.4shared.com/office/EwWqfpbgku/pdf-47581-21089.html
The series of alloys made use of is magnificent: weathering steel for patina, marine-grade aluminum for weight cost savings, and duplex stainless for corrosion resistance in extreme climates.