J. Scott Tucker completed an apprenticeship in engineering and then worked on railway construction under I.K. Brunel and on harbour works in the Azores, Bermuda and Malta. He came to the Cape Colony in 1854 and that same year investigated and reported upon the port of Table Bay and its improvement. His report included a plan of the harbour works. The next year he also drew up a plan of Table Bay, with soundings, which showed the harbour works proposed by Lieutenant-Colonel C.C. Michell*, a Mr Rendell, and himself. In 1857 he delivered evidence before a parliamentary select committee appointed to plan the first railway construction in the colony. The committee recommended that a railway line be built from Cape Town to Wellington. The contract for the work was awarded to the Cape Town Railway and Dock Company, with which Tucker had been associated in England. Meanwhile he was busy with railway construction in Brazil, but returned to the Cape to take up the position of colonial engineer in January 1859. That year he compiled a map of Table Bay with magnetic bearings of the lighthouses at Green Point, Mouille Point and Robben Island; a plan of the Mouille Point lighthouse; a plan of the lighthouse on Robben Island; and, with E. Pickering, plans of Somerset Hospital, Cape Town. One of his functions, until January 1860, was to supervise the building of the railway. Later the post of chief commissioner of roads was combined with his post of colonial engineer. He did not occupy the post for long. The Secretary of State in London referred to the mismanagement of the Public Works Department in 1863 and stated that Tucker was to seek other employment. Already in 1862 M.R. Robinson* was acting colonial engineer and his appointment was confirmed the next year.
In 1860 a Meteorological Committee (later renamed Meteorological Commission) was established at the Cape to organise, supervise and publish regular meteorological observations throughout the colony. It was chaired by Sir R. Southey* and Tucker was one of its eight members. The committee brought out its first report in 1862.
While at the Cape in 1859 Tucker established and commanded a corps of engineer volunteers named the "Cape sappers and miners". The corps was renamed the "Cape Engineers" in 1861. After leaving the Cape Colony Tucker worked as a consulting engineer in London. In 1865 he submitted proposals for railway construction in the Cape Colony, but nothing came of this initiative. He ended his career as superintendent of public works in Barbados. As a young man he painted in water colours, exhibiting his work in London in 1836.