I had the great privilege of sailing a brand new ship through the St. Lawrence back in 1994, and I definitely remember some hairy areas and tense moments - many of them dealing with sailing vessels - and that ship was only 225 feet long with very high maneuverability (MCM - Mine Countermeasures Ship)! When you add the fact that there is a current as well as the channel being narrow, the big container ship really has very few options in a case like this. The average "man on the street" is not very aware of how truly non-maneuverable some of these huge ships are, or how massive the effect of a seemingly small current can be on a large ship (rule of thumb on a tanker-type vessel is that 1 knot of current produces the same effect as 30 knots of wind).
Bottom line for me is: stay clear of channels as much as possible, and when in a channel turn down the music and turn up the VHF!
As to the big car carrier that seems like it should have "turtled" - one of the most fascinating subjects of study I've found is bouyancy and things like righting moments, metacentric heights, etc. that determine things like why certain ships can heel further than others, etc.
Here's an interesting tidbit relating to capsizing ships: on one of my older ships, we had gun mounts sitting relatively high off the water (weight high = less stability as we Mac sailors know!). The maximum heel angle from which that ship would recover was documented as 55 degrees (i.e. if you took a 56 degree roll you should expect the ship to continue over onto her side or upside down). However, the gun mounts were designed to fall off at 54 degrees - the "downhill" mount would fall over the side, thereby removing several tons of weight high on the ship and changing the righting moment enough that the maximum heel on that side of the ship would increase to around 60 degrees. Have you ever heard of a "gun tub" on a warship? It was called that because in essence the gun was a separate unit sitting in a "tub" on deck, and the shape of the gun and tub would decide how far over you could go before the gun fell out (it also made maintenance easy because essentially you just had to unplug the control and power lines, unbolt some retaining bolts and alignment bolts, and you could crane the whole gun mount off the ship).
- Andy26M
