Sharp

The Sharp (or Sharp Roberts) designation covers the standard 2-2-2 inside-cylinder passenger locomotives manufactured by Sharp Roberts & Co. of Manchester (later Sharp Brothers, then Sharp Stewart & Co.) from the 1840s, which became one of the most widely-built early railway locomotive types in Britain and were supplied to railways across the country as a reliable and well-proportioned standard passenger engine during the critical period of the railway mania and subsequent expansion in the 1840s and 1850s.

Sharp Roberts & Co. was one of the first and most prolific of the private locomotive manufacturers that emerged to meet the voracious demand for railway locomotives during the 1840s expansion. Based in Manchester — the heart of the industrial revolution and well-placed to supply the growing network of northern railways — Sharp Roberts built locomotives to well-established designs that offered railways reliable and standardised motive power without the lengthy delay of building their own works. The Sharp 2-2-2 single-driver express design was closely related to the Stephenson Patentee configuration and used inside cylinders driving a single central axle with leading and trailing carrying wheels, a layout that had by the 1840s become the accepted standard for express passenger work.

Sharp locomotives were supplied to railways including the Manchester and Birmingham, the Midland Counties, the Birmingham and Derby Junction, and numerous other companies during the 1840s–60s. None of the original Sharp Roberts passenger locomotives was preserved, though the locomotive manufacturing tradition they represent continues through the succession of Manchester locomotive builders.