What piping routes oil cargo from the manifold to underdeck pipelines?

The correct choice identifies the specific piping system designed to route oil cargo from the manifold to the underdeck pipelines. This system is known as a line drop. The line drop facilitates the transfer of liquid cargo by allowing the oil to flow vertically down from the manifold, which is located at the tanker's deck level, into the underdeck pipelines where it is distributed throughout the various tanks of the vessel.

Understanding the function of the line drop is crucial, as it handles the initial stage of cargo transfer operations, ensuring that the oil effectively moves from the external connection points at the manifold down into the secure storage of the tanker. It is designed to accommodate the necessary pressure and flow rates required during loading and unloading operations.

The other choices refer to different aspects of cargo handling and piping systems. Transfer refers to the overall operation of transferring cargo, while cargo fill specifically pertains to the process of filling tanks with cargo. A branch line typically refers to piping routes that diverge from the main line to service different tanks, but it does not specifically address the vertical transition from the manifold to underdeck pipelines as effectively as a line drop does.