Tuesday, July 20, 2010

Lessons Learned—Tow Allides with Moored Casino—Part I

Excerpt from U.S. Coast Guard “Proceedings of the Marine Safety & Security Council” magazine by Ms. Jennifer Kiefer, special correspondent to Proceedings.

Lessons learned from USCG casualty reports are regularly featured in Proceedings of the Marine Safety & Security Council magazine. These articles explore marine incidents and the causal factors, outline the subsequent U.S. Coast Guard marine casualty investigations, and describe the lessons learned as a result.

It is important to note that lives were lost in some of the marine casualties we present. Out of respect for the deceased, their families, and surviving crewmembers, we do not mention the name of any person involved.

On April 4, 1998, aboard the Admiral’s President Casino in St. Louis, Mo., more than 2,000 people were enjoying the casino’s entertainments. Just a short distance away, the M/V Anne Holly allided with a bridge, which set adrift most of its 14 barges. The current carried some of those barges back toward the casino, a permanently moored vessel, parting its mooring lines and swinging it out into the river.

Fortunately nobody aboard either vessel was seriously hurt and the damaged barges were quickly recovered. What makes this accident so noteworthy is how it set the stage for a number of valuable maritime safety improvements.

Waterway/Transit Hazards
In some ways the accident almost seemed inevitable. The Eads Bridge—where the allision began—has long been recognized as a difficult navigation area. Clearing the bridge’s diminishing vertical clearance requires steady steering and concentrated accuracy.

In addition to the bridge, the water itself presented an unusual challenge that night. High river conditions prompted the Coast Guard to impose a “daylight operation only” restriction on southbound tows over 600 feet. However, as the tow was traveling northbound, it was not affected, and the transit occurred during the more challenging night hours.

The Allision
Shortly after getting underway, the captain requested towing vessel assistance. Unfortunately there was only one vessel working at the time and it was unable to meet the request. The captain decided he would keep going without an assist vessel.

The vessel passed under two bridges and began the tricky approach to the Eads Bridge. The only passage possible, with the tow’s height and the increased flood stage, was directly under the center span. This approach required a course change and repositioning of the tow alignment. It is this steering maneuver that caused the allision and its domino effect.

As the forward barges passed under the bridge’s center span, the captain began steering to port to ensure the pilot house would pass under the center span. Partway under the bridge the vessel stalled, its forward movement halted by the opposing river current.

With the headway stopped, the current caused the tow to drift sideways toward the Missouri shore, pushing the tow’s port side barges into a bridge support and breaking its tow coupling. A number of the barges broke away and drifted back south.

Shortly thereafter, several barges allided with the Admiral’s bow and an entrance ramp, breaking the walkway loose from its moorings. Additionally, when eight of its 10 mooring lines parted, the casino vessel began to swing out into the river.

The captain released the remaining barges and raced downriver to place his bow against the casino vessel as its next-to-last mooring line parted. The combined efforts of the tow and the last remaining mooring wire held the vessel near the bank.

In part II we will outline the subsequent investigation report.

For more information:
Full article is available at www.uscg.mil/proceedings. Click on “archives” and “2006 Volume 63, Number 2” (Summer 2006).

Subscribe online at http://www.uscg.mil/proceedings/subscribe.asp.

Direct requests for print copies of this edition to: HQS-DG-NMCProceedings@uscg.mil.