National Transportation Safety Board Marine Accident Brief
The National Transportation Safety Board (NTSB) has issued Marine Accident Brief regarding the grounding and sinking of towing vessel Stephen L. Colby.
The uninspected towing vessel Stephen L. Colby struck hard bottom in the Upper Mississippi River (UMR) and partially sank off the right descending riverbank in LeClaire, Iowa, on November 25, 2013, at 1555 central standard time. Six of the nine crew-members on board made it to the riverbank on their own. The nearby towing vessel Aaron F. Barrett recovered the remaining three crewmembers from the partially sunken vessel. No one was injured.
The Stephen L. Colby was operated as a line haul boat by Marquette Trans-portation Co. The term line haul boat is commonly used in the inland towing industry to refer to a vessel that is in continuous opera-tion as it picks up and drops off barges at multiple locations along the waterway. At the time of the accident, the Stephen L.Colby was transiting upriver from St. Louis, Missouri, to Clinton, Iowa, to pick up 15 loaded dry cargo barges.
On board were a licensed master, a licensed mate (on western rivers, a mate is also referred to as a pilot), an engineer, and six other crewmembers serving as leadman, deckhand, deckhand trainee, or cook. The master of the Stephen L. Colby had worked on board the vessel in the role of master or mate for 2.5 years before the accident. The mate received his credential as mate for towing vessels 10 months before the accident, and the company considered him experienced on that section of the UMR.
At 1100 on the day of the accident, the mate relieved the master on navigation watch when the Stephen L. Colby was just south of United States Army Corps of Engineers (USACE) Lock & Dam 15 at UMR mile 483, near Rock Island, Illinois. The vessel continued northbound on the river to USACE Lock & Dam 14 at UMR mile 493.3, near Pleasant Valley, Iowa, where it passed through the lock at 1530. The Aaron F. Barrett, also heading north, passed through the lock with the Stephen L. Colby.
The Stephen L. Colby was ahead of the Aaron F. Barrett as it passed under the Interstate 80 bridge at UMR mile 494.5 about 1545 and proceeded upriver at 6.36.6 mph. At 1555, as the Stephen L. Colby approached mile 497, the mate, who was on watch in the wheelhouse, heard and felt the hull strike something near the bow area. He pulled back the throttles to slow the vessel and directed the engineer to check the engine room for damage. The engineer reported a significant amount of water spraying up through the deck plating. The mate sounded the general alarm signal and maneuvered toward the right descending riverbank to ground the vessel in shallow water. Using VHF marine radio, the mate also requested support from the Aaron F. Barrett, which was about 1 mile downriver at the time.
Once the vessel was grounded on the riverbank at about UMR mile 497, six of the crew disembarked safely ashore, and the mate, master, and engi-neer remained on board. The tug lost power as the water level quickly rose in the engine room, and it slid about 50 feet off the riverbank before the Aaron F. Barrett came alongside and held the Stephen L. Colby in position until the hull came to rest on the river bottom. The mate, master, and engineer then abandoned the partially submerged Stephen L. Colby and boarded the Aaron F. Barrett for safety.
Shortly after the Stephen L. Colby sank, the crew of the Aaron F. Barrett used a small aluminum workboat to deploy oil containment boom around the vessel. At first light on the morning after the acci-dent, local responders, oil recovery personnel, and the Coast Guard continued the response effort.
The USACE con-ducted soundings and a side-scanning sonar survey of the waterway near the accident site but did not locate any unknown hazards or obstructions on the river bottom. Using automatic identification system (AIS) data obtained from the Stephen L. Colby, the USACE overlaid the vessels trackline on the sounding results. The results indicated the vessel had remained within the navigable channel before the accident.
| The NTSB has authority to investigate and establish the probable cause of any major marine casualty or any marine casualty involving both public and nonpublic vessels under 49 United States Code 1131. This report is based on factual information provided by the Coast Guard from its informal investigation of the accident and NTSB onsite investigation and analysis. |
Source and Image Credit: NTSB
Further details may be found by reading the NTSB Marine Accident Brief
