El Faro and Buys Ballot Law


#1

Continuing the discussion from NTSB El Faro Report Meeting:

The reason this routing error seemed surprising is that when we first leaned of the loss we expected that it was because the El Faro had tried to get across and didn’t make and just gotten too close. This seem somewhat understandable.

But that’s not what happened - apparently the crew did not understand where the center of the system was - which is much more difficult to understand.

Here is what the C/M says on the 20-24 watch about what is expected as the ship approaches Joqauin:

uh– the word is pretty much what we knew this morning. we’re– we’re–
we’re on this intercepting and we’ve diverting to the south a little kind of
take it wide and stay out of the– the deeper swells. and uh we– we
could we’re predicting uhh forty knot winds umm on our starboard
beam. tonight. no– no– it’s on the stern now thirty. (oh boy/or forty)
we’re looking at fifty knots on the starboard beam. the latest and
greatest.– but that’s not hurricane force

  • So he expected winds on the starboard beam which is consistent with passing to the south of the eye.

Here is a diagram from David Burch Navigation Blog

wind dir 2712d

In the case of passing south winds would be expected aft, then shifting counter-clockwise to the starboard beam. - the green arrows in the diagram.

Here is what the second mate says at around 0320 hrs:

I think it’s shifting. cause that weather report say tha– uhh– west-
southwest wind which we were not getting but I think its starting to shift
west and now its coming back around. we’re gunna start getting it on
the starboard side.

This is also consistent with passing to the south of the eye, shift west then to the stbd side

What they must have experienced instead was change in wind direction shown by the blue arrows - starting on the port beam and shifting to dead ahead.

This if from Bowditch:

Perhaps the most reliable guide is the wind. Within the cyclonic circulation, a wind shifting to the right in the northern hemisphere and to the left in the southern hemisphere indicates the vessel is probably in the dangerous semicircle. A steady wind shift opposite to this indicates the vessel is probably in the less dangerous semicircle.

EDIT:

This is the C/M when he relieves the 2/M for the 04-08

I assume that we’re heelin’ to starboard (must be blowin’) port to
starboard.

Then the capt comes to the bridge:

CAPT 04:14:20.0 (oh) it’s it’s howling out there.

CM 04:14:24.6 (can’t tell the) direction * *.

CM (but) our forecast had it comin’ around to starboard.

CAPT? the wind?

CM 04:14:39.1 right.

CAPT 04:14:40.6 it will eventually.