sentences:  The idea had been suggested by Ralph Walker in 1796.The West India merchants employed him as an engineer, and with assistance from William Jessop, John Foulds and George Dance, who was the City of London's surveyor, he produced the detailed plans which enabled the Act of Parliament to be obtained.Jessop was appointed as engineer with Walker as resident engineer, in August 1799, but Walker departed in 1802 after a disagreement with Jessop following a structural failure of part of the works.