What is the name of the oldest surviving steam locomotive, built in 1814?

The oldest surviving steam locomotive, built in 1814, is Puffing Billy.

Puffing Billy was constructed in 1813–1814 for Christopher Blackett’s Wylam Colliery near Newcastle upon Tyne. Its designers were colliery engineer William Hedley, enginewright Jonathan Forster and blacksmith Timothy Hackworth. The locomotive hauled coal wagons along the Wylam waggonway to the docks at Lemington-on-Tyne.

Its importance lies in its use of ordinary wheel-to-rail adhesion rather than a rack railway. Two vertical cylinders drove a crankshaft beneath the frame, with gears transmitting power to the wheels. The heavy engine damaged the early cast-iron track, so it was rebuilt with additional wheels in 1815 and later returned to a simpler arrangement when stronger rails were installed.

Puffing Billy worked until 1862 and is now preserved at the Science Museum in London. A common mix-up is with Stephenson’s Rocket, Locomotion No. 1 or Salamanca: those locomotives are famous milestones, but Puffing Billy is the oldest surviving steam locomotive. Its sister engine, Wylam Dilly, is generally regarded as the second oldest.