Sanspareil II
Sans Pareil II was an 0-6-0 goods locomotive built by Timothy Hackworth at Shildon Works in 1837, representing a development of the colliery locomotive design tradition that Hackworth had refined through his work at the Stockton and Darlington Railway. Named in tribute to Hackworth's original Sans Pareil — his 1829 Rainhill Trials entry that had impressed the Liverpool and Manchester Railway judges despite ultimately losing to Rocket — the second Sans Pareil applied the six-coupled wheel arrangement to give better adhesion for the heavy goods and mineral work that Hackworth's locomotives were designed for, compared with the four-coupled arrangement of the original.
Hackworth had become one of the most experienced practical locomotive engineers in Britain through his work at the S&DR, understanding better than almost any contemporary how to build locomotives that would actually work reliably in the demanding conditions of colliery and mineral railway service. His designs emphasised robustness, accessibility for maintenance, and practical pulling power rather than the theoretical elegance or speed that was increasingly important to the express passenger railway operators. The six-coupled arrangement of Sans Pareil II reflected this priority: maximum tractive effort for heavy haulage.
No original Sans Pareil II survives, though the original Sans Pareil of 1829 is preserved at the National Railway Museum, York, and gives the best surviving impression of Hackworth's locomotive design philosophy and workmanship.
Design and development
After the original Sanspareil failed at the Rainhill Trials in 1829, Hackworth continued in his role as locomotive superintendent of the Stockton & Darlington Railway, building a series of heavy 0-6-0 coal engines that retained the vertical-cylinder, return-flue boiler layout he had championed at Rainhill. Sanspareil II, completed in 1837 at Hackworth's Soho Works in Shildon, was an enlargement of these earlier engines: a 0-6-0 with twin vertical cylinders mounted at the rear of the boiler, driving through long connecting rods to the rear axle, with side rods coupling all six wheels.
Hackworth's adherence to this layout, despite its declining popularity, reflected his belief that the return-flue boiler delivered better steam-raising for heavy slow-speed work — and the Sanspareil II proved highly capable on the Stockton & Darlington's coal trains.
Service and withdrawals
Sanspareil II worked the Stockton & Darlington's coal traffic from 1837 and remained in service for many years, eventually being withdrawn in the 1860s. Not preserved.
Identification features
0-6-0 with vertical cylinders mounted at the rear of the boiler, driving the rear axle through long connecting rods, with side-rod coupling to the front and middle axles. Distinct return-flue boiler with chimney at the same end as the cylinders. Visually quite unlike contemporary Stephenson practice.
Notable locomotives
- Sanspareil II (1837, not preserved)
