Mahogany also is used for drum making because of its integrity and capability to produce a very dark, warm tone (as compared to other more common wood types like Maple or Birch). Ringo Starr was said to have used mahogany drums, on the Beatles recordings of the 60s, manufactured by Ludwig.
Traditionally, ties (railroad sleepers to you) have been made of wood, but concrete is now widely used. Steel ties and plastic composite ties are currently used as well, although far less than wood or concrete ties. As of January 2008, the approximate market share, in North America, for traditional and wood ties was 91.5%, whereas the approximate combined market share for (all) concrete, steel, azobe (exotic hardwood) and plastic composite ties was 8.5%.