streamliner

noun

1. One who or that which streamlines something.

   “He turned out to be a brilliant expert on timber and on the lumber business in general, a specialist on soils, and an amazing streamliner of earth-moving work.”

2. Something with a streamlined design, especially railroad locomotives and passenger equipment.

   “[…] the three streamliners, still on their 29½ hr. schedule, start at 9.40 a.m., also turn-and-turn-about, and so arranged that the 9.0 and 9.40 a.m. departures are by different routes each day; [...].”

   “Californians brook no argument on the subject: for them the Southern Pacific's Coast Daylight was the world's most beautiful streamliner - a band of red, orange, and black drawn by appropriately styled Lima GS 4-8-4's.”

   “Two westbound freights were in the vicinity and the operator was kept busy passing them radio messages with the latest information on the late running of the streamliners, to allow the enginemen to keep moving until the last possible minute before they had to sidetrack their trains to let the fast trains overtake.”