Shell star Shell star A shell star is a star having a spectrum that shows extremely broad absorption lines, plus some very narrow absorption lines. They typically also show some emission lines, usually from the Balmer series but occasionally of other lines. The broad absorption lines are due to rapid rotation of the photosphere, the emission lines from an equatorial disk, and the narrow absorption lines are produced when the disc is seen nearly edge-on. Shell stars have spectral types O7.5 to F5, with rotation velocities of 200–300 km/s, not far from the point when the rotational acceleration would disrupt the star.
Shell plating more-or-less vertical Side Shell and is generally curved. See also Chine (boating). Side: is the plating which extends from the Bilge strake(s) to the Shear strake. Shear: is a special strake of the Side plating. It is the strake that connects the Side Shell to the Strength Deck. Stringer: is a special strake of the Strength Deck plating. It is the strake that connects the Strength Deck to the Side Shell. Strength Deck: is a special deck. It is normally the uppermost continuous deck and forms the top flange of the hull girder. Shell plating Shell plating is the outer-most