RIPKEN

RIPKEN 26.02. 1914 Minneapolis MN/USA 30.11. 2004 Minneapolis MN/USA John Frederick Ripken was educated at University of Minnesota, Minneapolis MN, obtaining the BS degree in civil engineering in 1934, and in 1941 the MS degree. He was there an instructor at the Dept. of Mathematics and Mechanics from 1937 to 1941, a research engineer at the Columbia University until 1945 within the Navy Underwater Sound Laboratory, and then until 1946 a hydraulic engineer of the Navy Department, at its David Taylor Model Basin, Bethesda MD. He then was from assistant professor to professor of hydrodynamics at his Alma Mater, thereby closely associated with its St. Anthony Falls SAF Hydraulic Laboratory. Ripken was a Fellow of the American Society of Civil Engineers ASCE, and a member of the American Society for Engineering Education ASEE. Ripken was closely associated with the SAF Hydraulic Laboratory, founded by Lorenz Straub (1901-1963). Further collaborators of this facility were Fred W. Blaisdell (19111998), Edward Silberman (1914-2011), Alvin G. Anderson (1911-1975), and Ripken. The latter was particularly interested in cavitation as a physical process and means to reduce the cavitation damage in hydraulic applications. Cavitation damage had become a major issue in hydraulic engineering from World War II, once the hydraulic heads increased above, say 50 m, generating flow velocities on chutes or in tunnels of more than, say 20 to 30 m/s. Originally, it was thought to improve the boundary material of these hydraulic elements, but it soon became clear that the only technical means was flow aeration, by which these damages were relatively easily controlled. Ripken has added to these questions and therefore may be considered an eminent hydraulician. Anonymous (1964). Ripken, John F. Who’s who in engineering 9: 1555. Lewis: New York. Ripken, J.F., Killen, J.M., Crist, S.D. (1965). A new facility for evaluation of materials subject to erosion and cavitation damage. SAF Project Report 77. University of Minnesota: Minneapolis. Ripken, J.F. (1966). Reduction of cavitation damage by surface treatment. SAF Project Report 81. University of Minnesota: Minneapolis. Ripken, J.F., Hayakawa, N. (1972). Cavitation in high-head conduit control dissipators. Journal of the Hydraulics Division ASCE 98(HY1): 239-256. Rouse, H. (1976). John F. Ripken. Hydraulics in the United States 1776-1976: 164. The University of Iowa: Iowa City. P

ROACH 25.12. 1813 Mitchelstown/IE 10.01. 1887 New York NY/USA John Roach was born in Cork County, Ireland. He came at age sixteen to the United States. He settled in Howell NJ and there learned the trade of an iron moulder. In 1840 he took a part of his savings and went to Illinois but had to give up because his plans failed. He therefore purchased in New York a small iron works. In 1856 he added land to this firm, but the shops were soon after wrecked by a strong boiler explosion. Roach now found himself penniless but his ability and integrity enabled him to borrow capital, and his business was resumed. In 1860 he obtained the contract for constructing an iron drawbridge over Harlem River in New York City, and thereafter he prospered so that by the end of the Civil War his foundry and engine works was one of the best in the US. Roach was one of the first to recognize the importance of the shift from wooden to iron vessels. He sent a representative to England to make a careful study of the methods of iron shipbuilding on Clyde River. In 1868, Roach purchased a number of smaller marineengine plants in and near New York City, and three years later then transferred his headquarters to Chester PA. Among the iron vessels he built were the City of Peking and the City of Tokio in 1874, for the Pacific Mail Steamship Company. He was also authorized by the Navy Department to design compound engines in vessels. He in parallel built the dry-dock at Pensacola FL, and in 1876 received the contract for two monitors. In 1883 the construction of three cruisers was begun but this contract was later cancelled, so that Roach resigned all these activities by 1885. While not the first to build iron vessels in the US, Roach launched a total of 126 vessels between 1872 and 1886, and therefore deserves the title ‘Father of the iron shipbuilding in America’. Anonymous (1887). John Roach’s life ended: Death of America’s most noted shipbuilder. New York Times (Jan.11): 1-2. Anonymous (1935). Roach, John. Dictionary of American biography 15: 639-640. Scribner’s: New York. Grose, H.B. (1895). John Roach. Atlantic: New York. P Swann, L.A. (1980). John Roach, maritime entrepreneur. Arno Press: New York. P Thayer, W.M. (1897). John Roach. Men who win: 164-182. Nelson & Sons: London. P Williamson, L.M. (1895). Prominent and progressive Pennsylvanians of the nineteenth century. Record Publishing Company: Philadelphia. P https://www.globalsecurity.org/military/facility/roach.htm P