Tow Allides With Bridge Due To Pilot’s Faulty River Current Estimation


The Incident

On April 6, 2016, about 0343 central daylight time, the towing vessel Michael G Morris, pushing 30 barges loaded with grain, allided with the Thebes Railroad Bridge at mile marker 43.7 on the Upper Mississippi River in Thebes, Illinois. The vessel and the bridge were undamaged, but all the barges broke away from the tow and 16 of them sustained a combined total of $850,000 in damage. No one was injured nor was any pollution reported.

The Michael G Morris tow was en route from St. Louis, Missouri, to Cairo, Illinois, when the accident occurred. The 30 loaded grain barges were arranged six across and five deep, making the entire tow (vessel and barges) 1,180 feet long and 210 feet wide.

How did it happen?

Heading downbound to the Thebes Railroad Bridge, the tow had to complete a large turn of about 113 degrees to maneuver through a bend in the river. Following that large turn was a second bend in the river, only 0.3 mile from the bridge, that required about a 35 degree turn. In addition, the current that day was strong at 3–4 knots.

About 0336, proceeding at a speed of 10.7 mph, the pilot, as intended, began to line up the bow of the tow with the left side bridge pier of the 651-foot-wide channel span, which he planned to steer through. The pilot told investigators that as the tow came out of the second turn and approached the bridge, he tried to come right in the river to line up for the passage, but the head of the tow continued to the left.

At 0343, the third barge on the port side of the tow struck the left bridge pier. The tow broke apart, with some barges hitting the bridge piers. All 30 barges drifted downstream; 28 of them stranded between mile markers 44 and 31. Two sank, were removed, and were declared total losses. Fourteen other barges sustained hull insets and punctures; some took on water.

At Heightened Risk

Even with a wide horizontal clearance, the Thebes Railroad Bridge is more difficult to transit than others because of the increased risk associated with the approach that includes two bends. The operator told investigators he had transited the bridge previously, but that the accident voyage was his first time doing so navigating the Michael G Morris. Further, high

water produced fast currents that increased the risk of allision while navigating a tow under the bridge.

Probable Cause

The NTSB determined that the probable cause of the allision of the Michael G Morris tow with the Thebes Railroad Bridge was the pilot not correctly accounting for the river current in the bend just above the bridge, resulting in his late and insufficient use of rudder while making the turn.

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Source: NTSB


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