Bridge tender’s distraction leads to delay, barge strike in Louisiana


Pat Rossi illustration

Forty minutes before the towboat’s scheduled arrival, the pilot aboard Marguerite L. Terral arranged for the opening of an Atchafalaya River swing bridge. But more than 30 minutes later, when the vessel and its six-barge tow rounded a bend less than two miles upriver, the bridge was still closed.

Eventually the bridge tender confirmed the span would open. The pilot cleared a fixed highway bridge upriver, then lined up to pass through the narrow opening in the swing bridge while counteracting strong currents. The approach proved insufficient, and two starboard barges struck a support pier at 1428 on June 9, 2017.

The bridge, owned by Union Pacific Railroad and located at mile marker 41.5 in Krotz Springs, La., required more than $4 million in repairs. Two barges also broke away during the incident.

National Transportation Safety Board (NTSB) investigators determined the bridge tender’s delay was the leading cause of the accident, while the pilot’s failure to manage the current was a contributing factor.

“The pilot’s reduction of forward speed to allow time for the bridge tender to fully open the drawspan reduced the water flow across the vessel’s rudders and thus diminished control of the towing vessel and flotilla,” the NTSB report said.

Terral River Service hired a contract pilot for the voyage from the company dock in Lettsworth, La., to Houma, La. The pilot replaced another company employee who lacked credentials for the entire route.

The “trip pilot” had more than 25 years of experience, including ample time in the tricky Atchafalaya around Krotz Springs. The pilot and captain discussed the voyage before departing, including plans for negotiating several bridges. The bridge tender at Krotz Springs informed them that the railroad bridge had a reported clearance of 17 feet, while the towboat’s air draft was 16.9 feet. The gap was small enough to require opening the bridge.

The captain conducted a wheelhouse training session with the pilot until about 1118, when the pilot took the conn. He navigated through several bridges without incident and at 1340 requested the Krotz Springs bridge to open for the tow’s 1420 arrival. According to the report, the tender confirmed the opening and said, “Come on down, and we’ll have it open for you.”

Soon after that communication, however, two Union Pacific supervisors arrived for an unannounced inspection. Investigators said the tender lost track of time following their arrival and failed to open the bridge as requested.

Marguerite L. Terral rounded “39-mile bend” at about 1416 and saw the bridge remained shut. The pilot slowed from 10 knots and twice called the tender over radio but got no response. A minute later, the tender hailed the towboat over radio and said he needed five minutes to open the draw span.

“The pilot then positioned the head of the tow above the highway bridge toward the left descending bank as an effort to offset the current’s lateral force, which was setting the tow toward the right descending bank,” the report said, adding that the pilot did not express any concerns to the bridge tender.

Three minutes before the incident, the tow was moving at 6 knots, aided by a 3.5-knot current in the swollen river. The pilot pushed the engines to full ahead once he saw the span mostly open, increasing the 699-foot tow to 8 knots.

The bow of the lead starboard barge, RM 3367, cleared the bridge pivot pedestal on the port side and pier No. 3 on the starboard side. But RM 3367’s aft section and the bow of the next barge in the string, RM 3304B, hit pier No. 3. Both RM 3367 and the lead barge on the port side broke away, but nearby vessels quickly corralled them.

The bridge sustained extensive damage. Pier No. 3 shifted horizontally, affecting the fixed-bridge structure. A fixed portion of the bridge truss also shifted horizontally, leaving the lift rail and the fixed rails out of alignment.

After the incident, the pilot admitted he was concerned upon seeing the span closed after clearing 39-mile bend. He also believed he had limited options other than pressing ahead. The NTSB acknowledged some maneuvers weren’t feasible, but suggested the pilot could have tried to stop the tow or slow down while using flanking rudders for control.

The Krotz Springs bridge takes no more than five minutes to open, and the NTSB said the bridge tender had plenty of time to complete the pilot’s request between the 1340 call and the 1420 scheduled arrival. Existing rules require “prompt opening” of a bridge upon receiving a request, although in this case the inspectors’ arrival appeared to distract the tender.

“Such inspections should never interfere with the safety of bridge operations. The drawspan should have been opened and available for the Marguerite L. Terral to safely transit at the time requested,” the report said.

A Union Pacific spokesman did not respond to an email seeking comment on the agency’s findings. Terral River Service also did not respond to inquiries about the incident.

By Professional Mariner Staff