A terrible tragedy

I’m sorry I’ve been too busy to post quite as much this week, although I have a number of posts half-finished and in the queue.

Today, however, my thoughts are with the families of the many young lives lost in the terrible tragedy off the coast of South Korea. Like everyone, I’m eager to know how this could have happened in calm seas, when the ship was reportedly near its intended course, and why the crew told the passengers to remain in place as the ship started to list.

9 Responses

  1. Assume the ship hit a rock at speed, and not a submarine. The incident happened about 9 am local time, when people were getting up. It was light on deck, so it likely hit something under the water. It appears that the ship listed heavily at once. In that situation the doors to leave one’s cabin are in the floor or the ceiling. Inside a ship it is as dark as in the belly of the whale. Lights typically go out, and one is left with emergency DC lights, which are weak. There will be enormous disorientation, and even greater difficulty in getting out of the cabins into the cabin flat, and then climbing stairs, perhaps with quantities of saltwater rushing down them.

    The only logical explanation for the huge loss of life is that many drowned in their cabins quickly, or were trapped there to die later. Even in an abnormal accident, that is most unusual.

    Ships have watertight doors (too few in my opinion on all passenger ferries) and it is possible that crewmembers tried to secure them. Such doors split the ship into floating compartments, and can inhibit sinking altogether. But it is also possible that disoriented and unfamiliar passengers opened them, with the effect of increasing flooding. But it appears more likely that crewmembers did not secure such doors and that electrically controlled doors (which exist on many ferries with large automobile decks) did not operate.

    I do not understand the order to “shelter in place” and would have expected an order to assemble at lifeboat stations, and to don lifejackets. That is so standard that any deviation is questionable. When a ship is flooding uncontrollably, there are many strange shudders and lurches, and a captain is always worried about putting weight on the wrong side so that the damage is increased (and 45 tons of passengers could have an appreciable effect) …but a ship’s crew can do several things at once so that, while the engineers are working on damage control, the cabin staffs should have been escorting passengers to safe places on the upper levels.

    So…(1) what did it hit (2) how bad was the initial damage (3) why the shelter in place order (4) did the emergency lights work (5) were watertight doors, manual or electric, put in place (6) what did the cabin crew do?

    Because automobile drive-on drive-off ferries have large empty spaces that can easily fill with water, and passenger ferries have large open stairways that allow water to pour down into lower levels, they tend to sink very fast indeed. But with the Cheonan in mind, one does wonder if it was not an accident inasmuch as so many young and alert people, who would normally be capable of rapid action, are victims.

    It is a horrific tragedy, and one cannot begin to fathom the agony of the parents, school teachers and students at that High School ..and the families of the other dead who, inevitably, will be overlooked because of the youth of most of the missing.

  2. One more thing. The enemy is “the list” since it makes everything much more difficult. It is standard practice to start “counterflooding” which means to pump seawater into tanks on the upper side of the list. This makes the ship sink lower into the water, and it can result in a lurch and list to the other side if one s not careful and methodical. Korean officers, merchant and navy, are generally of a high quality, and could be expected to counterflood promptly, and certainly within 15 minutes. This does not appear to have happened, judging from the pictures, and this suggests a total loss of electrical power, meaning serious immediate flooding in the engine room spaces.

  3. And a final comment. What few photographs that are available of the bottom of the vessel, as she turned belly up, do not appear to show impact damage. The absence of any damage would eliminate collision with rock or torpedo or submarine.

    This is most tentative. But if it is the case, then it is probable that this horrible tragedy occurred because some engineer was transferring fuel or ballast unwisely, and created an artificial list. That could then be exacerbated by an opening to the sea st a level that would normally be safe, so that water poured in and, essentially, grabbed at the ship, pulling it over..

    This is a possibility because ferries are generally shallow draft vessels, so that only a small amount of liquid transfer can affect their stability.

  4. Also you should have an email address or contact form somewhere on here… Or do you already? If so, make it easier to find!

  5. The latest reports are blaming the Captain for making a sudden course change. Consequent thereupon, the automobiles supposedly shifted to port, accounting for the bang that has been reported. That may be a contributing factor, but is unlikely to be enough. There is likely, in my view, a scenario where an engineer was pumping fuel from a starboard tank to a port tank, and that the port external car deck door was not properly closed.

    The course I have seen requires a turn to port at about the time the incident occurred. A light ferry moving at speed when set to turn to its left is more likely to lean to starboard or right than to port. But this vessel seems to have leaned to port, which is only likely if there were a transverse stability issue… and that most likely resulted from the movement of liquid (oil or water) between tanks at a reasonably high level on the ship.

    Her stabilizers were still extended in the sinking photographs, and it is possible that there was an interaction between stabilizers, marginal transverse stability and “free surface effect” (which comes from sloshing of liquids around in half empty tanks,) that caused the ship to lurch to port instead of just staying upright.

    But even a lurch is not enough. There has to have been some way that seawater can have entered the ship at a reasonably low level, which suggests improper securing of a door near the water level, probably the port cardeck external door.

    Finally, the Captain of course will get a share of the blame, but stability is normally the preserve of the Chief (deck) Officer, while movement of liquids is the preserve of the Chief or Second Engineer in conjunction with the Chief Officer. At about 845 am, the Chief Officer will likely have just come off watch and be eating breakfast, not wanting to be disturbed by a dirty engineer. There are instances of extremely poor communications between deck and engineering officers in every merchant marine, and that may also be a contributing factor.

    There are some remarkable photographs of exceedingly brave divers onboard while the ship is actively sinking, trying to save passengers and also examining her hull for injury: what I am thinking about is those where they are inside a large circular area, which is the bow thruster, (which is a propeller to move the nose of the ship sideways during berthing.) It seems that the Korean armed forces did everything it was possible to do, and fast.

  6. Last comment today. Video of the rescue (which shows immense skill by the Korean military) also shows all Carley floats, or rescue rafts, still attached to the ship, even those on the side leaning towards the water. That strongly suggests the crew ran away.

  7. Also, In some of the video coverage i observed large amounts of water intermittently flushing from what looked like bilge vents on the port side during the sinking.
    Was the bilge system open or damaged in some way?