At the Rainhill Trials,
Sans Pareil was excluded from the prize because it was slightly over the maximum permitted weight. Nevertheless it performed very well, but had a strange rolling gait due to its vertical cylinders and the draft from the
blastpipe was, in Hackworth's trademark style, very strong, so most of the coke was expelled out of the chimney unburnt. It was this more than its antiquated design that caused its poor fuel economy. It was pulled out of the competition because of a cracked cylinder: the design thickness for the cylinder walls was some , but at the point of failure, it was found to be a mere . The manufacture of the cylinders had been contracted out to
Robert Stephenson & Co., who were accused by Hackworth's supporters of sabotage, but as he had had over twenty cylinders cast and chose the best two for the locomotive, foul play on the part of the Stephensons was unlikely. After the trials, the Liverpool and Manchester Railway bought
Sans Pareil as well as
Rocket. It was subsequently leased to the
Bolton and Leigh Railway where it ran until 1844. It was then used by
John Hargreaves as a stationary boiler at the
Coppull Colliery,
Chorley until 1863. Thereafter,
Sans Pareil was restored and presented to the Patent Office Museum (which later became the
Science Museum) in 1864 by
John Hick. The engine now resides at the
Shildon Locomotion Museum on static display. ==Replica==