<Table> <Tr> <Td> </Td> <Td> This article needs additional citations for verification . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . (July 2010) (Learn how and when to remove this template message) </Td> </Tr> </Table> <Tr> <Td> </Td> <Td> This article needs additional citations for verification . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . (July 2010) (Learn how and when to remove this template message) </Td> </Tr> <P> An oiler (also known as a "greaser") is a worker whose main job is to oil machinery . In previous eras there were oiler positions in various industries, including maritime work (naval and commercial), railroading, steelmaking, and mining . Today most such positions have been eliminated through technological change; lubrication tends to require less human intervention, so that workers seldom have oiling as a principal duty . In the days of ubiquitous plain bearings, oiling was often a job description in and of itself . </P> <P> Today, shipping is the economic segment that most thoroughly retains the notion of the oiler as a separate position . On a merchant ship, an oiler is an unlicensed rate of the engineering department . The position is of the junior rate in the engine room of a ship . The oiler is senior only to a wiper . Once a sufficient amount of sea time is acquired, the Oiler can apply to take a series of courses / examinations to become certified as an engineer . </P>

What is the work of oiler in ship
find me the text answering this question