Weather router Chris Parker analyzes El Faro debris movement

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The U.S. Navy found the wreckage of El Faro last week, and one of the results may well be an estimate of how many shipping containers were set free. It is important to note that El Faro, which went down Oct. 1 off Crooked Island in the Bahamas during Hurricane Joaquin, is not a container ship; she was a roll-on/roll-off, lift-on/lift-off vehicle carrier, but the 790-footer carried nearly 400 containers on deck, too.

All Is Lost was a dreadful movie. Robert Redford’s character makes an inexplicable series of bad choices, which culminate when he accidentally sets his life raft on fire. This final idiocy manages to cancel out all of the previous idiocies — no EPIRB, for starters — and he is rescued. The most realistic moment in the movie happens in the first few minutes when his boat smacks into a floating container. Collisions with containers are rare, but they do happen.

It is estimated that as many as 10,000 containers are lost at sea each year, and in February 2014 a Maersk vessel lost more than 500 in a single incident in the Bay of Biscay.

Even though El Faro was an older ship, the twist-lock latching bars for securing the containers to the deck were state of the art, so it’s possible that most of them went to the bottom. But we know that at least one El Faro container broke loose because it washed up in the Exumas. It appears to have been a refrigeration container. These usually incorporate GPS monitoring so owners can view temperature settings remotely via satcom.

What looks like a container washed up in the Exumas a few weeks after El Faro sank during Hurricane Joaquin.

What looks like a container washed up in the Exumas a few weeks after El Faro sank during Hurricane Joaquin.

I asked Chris Parker of the Marine Weather Center to analyze the path any loose debris might take. Parker is my weather router because no one cuts down island forecasts into chunks as small as he does, and his forecasts are informed by real-time feedback from hundreds of his customers with single-sideband radios.

This is Parker’s analysis, which was completed late last week:

I started with an assumed position of El Faro at the time of distress, approximately 23˚ 20N and 70˚ 00W.

I estimate debris floating just-awash — no windage but motion influenced some by wind speed/direction, which causes near-surface waters to move with the wind — would have moved about 55 miles in a direction about 280˚ True.

My reasoning:

• Five days of wind blowing the debris toward the NE, average wind speed 11k, assume debris traveled 8 miles NE.

• Twenty-one days of wind blowing debris toward W (light NNW motion offset by strong WSW motion on four days), average wind speed 13k, with four of these days averaging 21k (stronger wind would cause more than a linear increase in movement, as friction of wind on water increases in a more-than-linear fashion with increasing wind velocity). Assume debris traveled 48 miles W.

• Net motion is about 280˚ T, distance = 55 miles.

I largely ignored wind from Oct. 1-2 (the day of and day after the sinking) because, as Joaquin completed a slow, steady anti-cyclonic (clockwise) loop of waters within 50 miles east of Long Island, Bahamas, El Faro’s debris likely would have experienced fairly uniform and opposing wind (and wind-induced currents), suggesting to me not much net motion over the 36 hours after the sinking.

From the starting position, 55 miles in a direction of about 280˚ might place the bulk of “awash” debris very close to Rum Cay.

Sea surface currents

Normally the Antilles Current transports water from along and north and east of the Leewards, Virgins and Puerto Rico northwestward through and just north of the Turks & Caicos and Bahamas islands.

However, my analysis of both the HYCOM and RTOFS gridded currents data suggests that the Antilles Current has not been flowing consistently nor strongly, and indeed there may be a counter-clockwise-rotating eddy north of San Salvador and Cat Island, which might tend to move any debris located north of San Salvador, northeast of Cat Island and east of Eleuthera in an easterly direction (opposite the normal northwesterly flow).

My opinion is the bulk of submerged/awash debris is probably still in a box:

• north of Crooked Island to near San Salvador

• along and east of Long Island's east coast

• along and south of the southerly shore of Cat Island

parker1105

Debris with more windage is likely to have been driven into Exuma Sound, and most of this debris is probably still in Exuma Sound or has come ashore on islands bordering Exuma Sound.

Next I turned to Ben Ellison, who maintains the website Panbo, the marine electronics hub. I had always hoped that forward-looking sonar, which has finally come of age with products from Garmin and Navico, would be a solution to the problem of finding awash containers. My theory was that with proper alarm settings, the helmsman would gain precious seconds to throttle back or turn away. Ellison, the leading independent tester of marine electronics, dashed those assumptions.

Based on personal experience, however, I am convinced that radar is a useful tool for container detection. During the Nordhavn Atlantic Rally in 2004, I was on an early morning watch on Atlantic Escort when I noticed a soft, but persistent radar return ahead of the returns from the 11 other boats. Over the radio I confirmed that others were seeing it, too. As we got closer it became apparent that the target was essentially stationary.

Our boats moved outward and passed to either side of the target. It was a starlit night, and we took the target to starboard. I stepped out of the pilothouse and trained powerful binoculars when the target should have been abeam. Nothing. I believe the soft return was a shipping container awash that was returning a radar signal because of the calm sea state.

We are approaching the time of year when many U.S. boats are transiting the Bahamas en route to the Caribbean. Anyone navigating around the northern tip of Long Island en route to the Turks & Caicos should be more cautious than usual. I would avoid running through Chris Parker’s box at night. I would wait for calm seas, and I would keep the radar on and the gain up.