1963 Eastern Hills High School EHHS Highlanders: Abandon Ship!

Tuesday, January 17, 2012

Abandon Ship!

Friday, three days ago, the Italian cruise ship, Costa Concordia, struck rocks near a Tuscan island off Italy's Mediterranean coast. Aboard were over 4200 people and to date the losses appear to be fairly minimal. However, the pictures of such a large ship on its side are striking.

Almost immediately, reports were in circulation of the ship’s captain behaving in a cowardly manner as the ship was foundering. Tuesday, this morning, recordings of radio transmissions between his company’s dispatcher and the captain began to broadcast over news media. The recordings appear to support the earlier reports…the captain had abandoned his ship among some of the first of those subsequently recovered by rescuers.

Having served, in the distant past, as a member of a blue water ocean-going crew, I have some modest knowledge of those who go down to the sea in ships. There’s about 60,000 miles of modest sea-going knowledge sitting somewhere in my ROM.

This old salt’s quick thoughts are: (1) it’s dumb to be that close to a shore unless leaving or entering a port; (2) current day super size cruise ships look awfully top heavy—they fail my stability eye-ball test; (3) the captain, age 52, is a card-carrying member of the Italian chapter of the FBG; (4) there are no mitigating circumstances in this event; (5) how big is that lumbering beast?

The Costa Concordia and the USS Reagan are about the same size, nominally 114,000-tons. Each is nominally about 1000-ft long; the Reagan is incrementally larger in both dimensions. Center of gravity and moment arm, two fundamental concepts taught to every Freshman future engineer, determine a floating vessel’s stability. It would be desirable to have the CG located underwater on the keel. However, that is not possible. The next best design would place the CG as low as possible and would preclude stacking too much weight high above the waterline.

Although this current event appears to be a matter of stupidity and not a CG issue, I think the CG issue is worth planting near these dramatic images, as it’s a question that has long dogged my acceptance of fun in the sun cruising. It has always seemed to me that a large, top-heavy cruise ship would be inherently unstable in a heavy sea-state--stabilizers and such notwithstanding.

Add in the presence of captains like this current character who are legally the absolute “authority” aboard that ship while it’s in International waters, frequent main propulsion failures, frequent food poisoning, frequent missing passengers presumably gone overboard, foreign non-English speaking crews, and a few other troubling conditions…nope, I’m content here onshore.

Before a Navy ship is deployed to foreign waters it always undergoes strenuous sea trials to prove the integrity of its systems and structures. Some of the most dramatic trials are the high-speed runs with throttles full open, the props thrown into full reverse while at full speed, and high speed turns as the Reagan is doing below. Note both the list and the demonstration of the vessel’s stability. It’s probably making in excess of 35-knots…I think the rudder is thrown to its full travel in that direction, so it’s bearing the full force of all that water pushed against it by a quickly moving 114,000 ton vessel…that’s a lot of stress on the rudder and its support structures.

Draught is another stability contributor. The more the better; however, the more you have, the fewer the ports that can handle the ship. The Reagan has a 37-ft. draught; the Costa Concordia, 24-ft.

The pictures coming in from this event are fascinating…I’ve never seen anything this dramatic before, nor thankfully did I ever see a ship sink. Images of a sinking ship have always struck me as a spooky scene, and these show some remarkably clear views of the underside of those top-heavy vessels that trouble me so. I would like to see more mass hanging under the water line.