Question 70 3AE02 - Third Assistant Engineer (Alt)

The Correct Answer is D **Explanation for Option D (Correct Answer):** The longitudinal framing system is characterized by the primary strength members (frames) running parallel to the centerline of the ship, i.e., in the **fore and aft** direction. These longitudinal frames primarily resist bending moments that occur along the ship's length (hogging and sagging). To provide support for these numerous longitudinal members and to maintain the cross-sectional shape of the ship, large, sturdy transverse members, known as **web frames** (or belt frames), are incorporated. These web frames are typically **widely spaced** compared to the closer spacing used in a purely transverse framing system. This arrangement provides an efficient structure, particularly for larger vessels, tankers, and bulk carriers. **Explanation of Incorrect Options:** * **A) With longitudinal framing, longitudinal frames are fore and aft between closely spaced transverse web frames.** * While the longitudinal frames run fore and aft, the distinguishing feature of the longitudinal system is the *wide spacing* of the supporting transverse web frames. Closely spaced web frames would negate the efficiency benefits of the longitudinal system. * **B) With longitudinal framing, longitudinal frames are port and starboard and supported by widely spaced transverse web frames.** * This is incorrect because "port and starboard" refers to the transverse direction (athwartships). Longitudinal frames run in the length of the ship, which is the fore and aft direction. * **C) With longitudinal framing, longitudinal frames are port and starboard between closely spaced transverse web frames.** * This is incorrect on two counts: the frames run fore and aft, not port and starboard, and the transverse web frames are widely spaced, not closely spaced.