William Warburton Knox (W.W.K.) Sparrow and W.B. Sparrow, civil engineers employed by the Cape Government Railways, appear to be the same person. W.B. Sparrow, associate member of the Institution of Civil Engineers of Ireland, became a member of the Cape Society of Civil Engineers in 1904. At that time he was employed by the Cape Government Railways and was stationed at Ceres Road. In June the next year he presented "Notes on the selection of a bridge for spans of 100 ft - 250 ft", a paper that was published in the society's Minutes of Proceedings (1905). By the end of that year his name in the society's list of members was replaced by W.W.K. Sparrow, associate member of both the Institution of Civil Engineers of Ireland and of the American Society of Civil Engineers. He was still employed by the Cape Government Railways, but was stationed at Queenstown, where he remained until at least 1908.
Similarly, W.B. Sparrow, of the Cape Government Railways at Ceres Road, became a foundation member of the South African Association for the Advancement of Science in 1902. However, by 1906 his name had been replaced by W.W.K. Sparrow, stationed in the district engineer's office of the railways at Queenstown. His membership of the association had lapsed by 1910.
W.W.K. Sparrow was the son of Reverend William Sparrow and his wife Cecilia Jane Knox. He became a railroad engineer with world-wide experience in the construction and operation of railroads. He was born in Ireland, was educated in England, and worked in South Africa for ten years. He then went to the United States where he became chief engineer of the Chicago, Milwaukee and St Paul Railroad Company in or before 1918. A few years later he was promoted to vice-president of this company, with responsibility for finance, accounting and real estate, a position he held until his death in 1939. In 1908 he married Mary Batchelor in Qeenstown, Eastern Cape.