A tide in the affairs of men...

By now, most people know a massive container ship, named The Dali, struck a pier or support of the Francis Scott Key Bridge in Baltimore, plunging eight road workers into the water. At this time, rescue efforts have failed to find six of these workers, and the authorities now presume assume they have died, either in the accident or in the cold water shortly after.

Most news reports to date have emphasized the absence of information, saying authorities do not know what caused the disaster. We do not know exactly what caused The Dali to lose power at the worst possible time, but we do have a general sense of  the sequence of events. The ship quite clearly suffered a major failure in the engine room. The crew dropped the anchor, which did not stop the ship. When the crew or pilots saw their vessel drifting into the bridge, they sent out a Mayday, which allowed the port authorities to stop traffic on the bridge; this certainly saved lives.

 

The crew could not stop the ship for a number of reasons. News reports have tended to highlight inertia as a problem; a three hundred meter ship has a huge mass and corresponding momentum. However, the crew faced another problem once The Dali lost power. According to Reuters The Dali struck the bridge at 1:30 local time (0530 UTC). The tide tables for Baltimore place low tide at 2:36 local time (0636 UTC). That means The Dali had followed the common practice of leaving port on a ebb tide. The tidal currents at that time ran from the port to the sea, taking the ship with them. The Key Bridge simply lay on the path from the port to the sea, and both tide and momentum carried the ship directly into it. 

Investigators will have to determine exactly what part each factor played in the crash, but we do know at least one thing about the tide: with a full moon, the Sun, Earth and Moon aligned, which tends to produce stronger tides than usual. Also, as anyone who has sailed in New York Harbour can tell, long narrow bodies of water, such as ports, tend to have stronger tidal currents than average.

Perhaps investigators will report the part the tide played in this tragedy. Perhaps they will not mention it, as just a given, part of the nature of any port. But I think we should pay heed to it, if only as a reminder of the way the sun gives us the energy to live, the moon keeps our calendar, and the vast ebb and flow of the water these celestial bodies set in motion determines so much about our lives, and sometimes our deaths.