page_title: Josias Jessop
section_title: Consulting engineer
hierarchical_section_title: Josias Jessop / Consulting engineer
caption_attribution_description: English: Kings Mill Viaduct. Dating from 1817, Kings Mill Viaduct carried the Mansfield and Pinxton tramway across a small stream. The main line (still open as part of the Robin Hood line) was diverted round this section of the tramway; the viaduct now carries a footpath.
context_page_description: Josias Jessop was a noted canal engineer, and second son of William Jessop, one of the great canal engineers of the late eighteenth and early nineteenth centuries. He was trained by his father, and worked under him on his early projects, but proved his abilities during the construction of Bristol harbour. He became an independent consulting engineer from 1811. He died fourteen years later, a little before he reached the age of 45.
context_section_description: Now aged 30, and with his abilities as an engineer acknowledged, he became an independent consulting engineer. In 1811 he surveyed the route for a canal linking Godalming on the River Wey Navigation to Newbridge on the River Arun. Following the issuing of a report in August and a prospectus in October, he re-surveyed the route, and in May 1812 suggested a revised route, at an estimated cost of £86,000. An Act of Parliament was obtained in April 1813, to authorise an 18.5-mile (29.8 km) canal with 23 locks suitable for 30-ton barges. All of the main structures, including aqueducts, bridges, locks and lock-keepers' cottages were designed by Jessop, and construction was managed by May Upton, the resident engineer. The Wey and Arun Canal project was completed in September 1816, having cost £103,000.
  In 1813 he surveyed and planned the Western Branch of the Montgomeryshire Canal. The canal had been opened to Garthmyl in 1797, but had not progressed any further because of a lack of finance. The existing section became known as the Eastern Branch, and Jessop surveyed a 7.5-mile (12.1 km) extension with 6 locks, which ran from Garthmyl to Newtown. His plans were accepted in July 1814, but there were delays in obtaining an Act of Parliament, as a result of opposition to the plans. However, an Act was obtained in 1815, and Jessop oversaw the project between then and 1819, when construction was completed. John Williams was the engineer on site, and the project cost £53,390. Although the construction work was completed in March 1819, it was not reported to be finished until December 1821.
  In 1805, Benjamin Outram, the owner of the Butterley Company, died, and the Jessop family moved from Newark to Butterley Hall, so that William Jessop, the younger brother of Josias, could take over as manager of the company. Since 1794 they had manufactured cast iron plate rails for tramways, but in 1813, experimented with I-section edge rails, and Josias used these rails on his next project, an 8-mile (13 km) railway which ran from Mansfield to the Cromford Canal at Pinxton. Construction of the Mansfield and Pinxton Railway was authorised on 16 June 1817, and an opening ceremony was held on 13 April 1819, close to a viaduct which carried the railway over the River Maun at Mansfield. A local newspaper report described it as "the beautiful five-arch bridge, constructed under the direction of Mr. Jessop, the engineer." It was adapted for locomotive traffic in 1847, and is now used as a footpath. It was restored in 1990, and is a grade II listed structure.
  Jessop was also consulted on harbour works, recommending an extension to the east pier at Newhaven harbour in 1819, which was completed the following year, while is 1823 and 1826 he reported on Plymouth Breakwater, in the first instance jointly with Thomas Telford, George Rennie and John Rennie, and in the second with William Chapman and John Rennie.
  His final project was the Cromford and High Peak Railway, which crossed the Pennines to link the Cromford Canal to the Peak Forest Canal. He surveyed the route in 1824, and proposed a 33-mile (53 km) line, which would use a series of steep inclines powered by stationary steam engines to raise the level by 990 feet (300 m) on the Cromford side, and drop it by 250 feet (76 m) to reach Whaley Bridge. An Act was obtained in May 1825 and construction began, with Thomas Woodhouse as the resident engineer. Woodhouse saw the project through to completion in 1831, after Jessop's death in 1826. The summit tunnel includes a stone inscribed 'Josias Jessop Engineer'.
  Some idea of the stature of Jessop as an engineer can be gained from events concerning the proposed Liverpool and Manchester Railway. The original bill had been withdrawn from Parliament in 1825, as George Stephenson's survey was flawed, and his ability to present evidence incompetent. George and John Rennie then prepared a new plan, which resulted in an Act of Parliament being obtained in May 1826, after George Rennie and Jessop gave evidence. The two Rennies were asked to become engineers, but stated 
caption: Jessop's five-arched viaduct for the Mansfield and Pinxton Railway
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