Salamanca
Salamanca was Matthew Murray's 1812 rack-and-pinion steam locomotive, widely regarded as the world's first commercially successful steam locomotive. Built by Fenton, Murray and Wood of Leeds to John Blenkinsop's patent rack-and-pinion adhesion system, the engine entered service on the Middleton Railway between Leeds and Middleton Colliery on 12 August 1812, making the Middleton Railway the world's first commercially-operated steam railway.
The design solved the problem that had defeated Penydarren and the 1805 Wylam engine: contemporary cast-iron rails could not support steam locomotive weights on gradients. Blenkinsop's solution was a rack-and-pinion adhesion system, a separate toothed rack laid alongside the running rails engaged a gear pinion on the locomotive, providing positive adhesion independent of wheel-rail friction. Murray's engine had twin vertical cylinders driving a central gear pinion through cross-beams and connecting rods, significantly more sophisticated than Trevithick's single-cylinder designs.
The engine was named after Wellington's victory at Salamanca on 22 July 1812, the news of which had reached Britain shortly before completion. First public running was on 12 August 1812 in front of large crowds; the engine successfully hauled 30 tons of coal from Middleton Colliery to Leeds. Salamanca was the first of four engines built to the same design over 1812–1813, the others being Prince Regent, Lord Wellington, and Marquis Wellington.
The Middleton Railway became the world's first commercially-operated steam railway and the four Murray-Blenkinsop engines worked the line successfully for approximately 20 years. Salamanca itself ended in disaster: on 28 February 1818 the engine's boiler exploded near Middleton, possibly due to driver James Hewitt tampering with the safety valve to increase pressure, killing Hewitt. The remaining engines continued in service through the 1820s and into the 1830s before being progressively replaced by simpler wheel-rail-adhesion locomotives derived from Puffing Billy and Rocket practice.
No original component of Salamanca survives. The Middleton Railway itself is preserved as a heritage railway, with a small museum at Moor Road station, Leeds, interpreting the rack-and-pinion era.
Design and development
By 1811 John Blenkinsop, the agent of Brandling's Middleton Colliery near Leeds, faced the same problem that had defeated Penydarren and the 1805 Wylam engine, contemporary cast-iron rails could not support steam locomotive weights, particularly on the gradients out of the colliery. Blenkinsop's solution was a rack-and-pinion adhesion system: a separate toothed rack laid alongside the running rails would engage a gear pinion on the locomotive, providing positive adhesion independent of the wheel-rail friction. The arrangement was patented in April 1811 (Patent No. 3431).
Blenkinsop commissioned Matthew Murray of Fenton, Murray and Wood, Leeds (one of the leading early-19th-century engineering firms) to build engines incorporating the rack-and-pinion drive. Murray designed a twin-vertical-cylinder locomotive with the cylinders driving a central gear pinion, significantly more sophisticated than Trevithick's single-cylinder designs. The use of two cylinders gave smoother running and eliminated the need for the substantial flywheels Trevithick had used.
The first engine, Salamanca, was completed in early August 1812. The engine was named after Wellington's victory at Salamanca on 22 July 1812, the news of which had reached Britain shortly before. First public running was on 12 August 1812 in front of large crowds. The engine successfully hauled 30 tons of coal from Middleton Colliery to Leeds.
Service and withdrawals
The Middleton Railway became the world's first commercially-operated steam railway from 12 August 1812. Salamanca and the three subsequent engines (Prince Regent, Lord Wellington, and Marquis Wellington) worked the line successfully for approximately 20 years. The economic case was clear, the engines reduced haulage costs substantially against horse-drawn working.
Salamanca itself ended in disaster. On 28 February 1818, while in service, the engine's boiler exploded near Middleton, possibly due to driver James Hewitt tampering with the safety valve to increase pressure. Hewitt was killed in the explosion. The remaining engines continued in service through the 1820s and into the 1830s.
By the early 1830s the rack-and-pinion adhesion principle was being superseded by the simpler wheel-rail adhesion of Puffing Billy-type engines and (especially) the Stephenson Rocket-derived designs. The Middleton Railway abandoned its rack rails in 1834–1835 and was converted to conventional adhesion working. The Murray-Blenkinsop engines were progressively scrapped through this period.
Identification features
The engine had a substantial cylindrical boiler with two vertical cylinders mounted on top, driving a central gear pinion through cross-beams and connecting rods. The whole engine sat on four wheels (two pairs, all unflanged), with the central rack-pinion engaging a toothed rack on a separate rack-rail laid alongside the running rails. The engine was approximately 8 ft long and weighed approximately 5 tons. The class was named after British military victories in the Peninsular War, Salamanca commemorated Wellington's victory of 22 July 1812 (a few weeks before the engine's first run).
Numbers and names
None (named locomotives)
Notable locomotives
- Salamanca (1812)
- Prince Regent (1812)
- Lord Wellington (1813)
- Marquis Wellington (1814)
Allocations and regions
- Middleton Railway (Leeds–Middleton Colliery), from 1812