James Green (engineer)
James Green (1781–1849) was a civil engineer and canal engineer, who was particularly active in the South West of England, where he pioneered the building of tub boat canals, and inventive solutions for coping with hilly terrain, which included tub boat lifts and inclined planes.
Although dismissed from two schemes within days of each other, as a result of construction problems, his contribution as a civil engineer was great.
He then worked with John Rennie on a number of projects around the country, until 1808, when he moved to Devon, and established a base at Exeter.
He submitted plans for the rebuilding of Fenny Bridges, in East Devon, which had collapsed only 18 months after their previous reconstruction.
He was also involved with extending and enlarging the Exeter Ship Canal, a project which started in 1820 and lasted for seven years.
He was faced with the engineering problems of building canals in hilly terrain, where the water supply was limited.
Each bucket was capable of holding 15 tons of water, and they were attached to either end of a chain, which passed over a drum.
The process was quick and efficient, raising a tub boat in about four minutes, which was half the time required when the standby 16 hp (12 kW) steam engine had to be used.
[1] Green took his inspiration for the methods of operating the planes from the work of Robert Fulton, but brought his own engineering skills to make a workable system.
As at Bude, the canal was designed for tub boat operation with a single, double track, inclined plane powered by a water wheel.
The lift consisted of two chambers, each holding a caisson, which was joined to the other by chains which passed over a series of wheels.
Commissioning tests indicated that a bucket capable of holding 25 tons of water would be needed, but the shafts were not big enough.
Ultimately, the power was supplied by a water wheel, but Green had to admit that he could not complete the inclines, as he had underestimated the cost of their construction by a huge margin.
