This 1930 cover image depicts a group of four barge-mounted derricks using 100-ft-long booms to carefully place an assembly of pipes in a trench at the bottom of the Harlem River, which separates the northern tip of Manhattan Island in New York City from Bronx County. The assembly of 36 wrought iron pipes was held in position with wooden collars placed 10 ft apart, and were curved at both ends where they came onshore. The pipes were coated with enamel to resist corrosion from saltwater, as the Harlem River is a tidal estuary. The derricks, working in unison, lowered the pipes gently in 1-ft stages to prevent any undesired bending or buckling. The 620-ft-long pipe assembly carried power lines for the New York Central Rail Road. The pipelaying process took six hours.