Question 47 3AE02 - Third Assistant Engineer (Alt)

The Correct Answer is A. **A) Duct keel (Correct):** A duct keel is specifically an internal passage of watertight construction fitted along the centerline within the double bottom of a ship. Its primary function is precisely what is described in the question: to allow access for inspection, maintenance, and to safely house and carry essential pipework (such as ballast, fuel transfer, or firefighting lines) along the length of the vessel, often running from the forepeak back towards the engine room bulkhead. **B) Pipe keel (Incorrect):** While the term "pipe" relates to the function of carrying pipes, "pipe keel" is not the standard or recognized naval architecture term for this specific structure. The structure housing the pipes is known as a duct keel. **C) Vertical keel (Incorrect):** The vertical keel (or center girder) is the main structural member running along the ship's centerline within the double bottom. While the duct keel incorporates the vertical keel structure, the vertical keel itself is purely a structural member providing strength and does not necessarily create an accessible, watertight tunnel or passage for personnel and pipework unless it is specifically designed as a duct keel. **D) Bar keel (Incorrect):** A bar keel is an older type of keel construction, used mostly on small vessels or those with single bottoms, where the keel is simply a solid rectangular bar fitted externally along the centerline. It offers no internal space or passage for pipework.