had been pipelining

• past perfect progressive

  past perfect progressive

  Used to describe an action that was ongoing continuously in the past up until another past event interrupted it.

  of pipeline.
  pipeline

  noun

  a long tubular conduit or series of pipes, often underground, with pumps and valves for flow control, used to transport crude oil, natural gas, water, etc., especially over great distances.

Related Words

• agenda
• almanac
• card
• chronology
• diary
• docket
• journal
• lineup
• list
• program
• table
• timetable