NTSB: Lack of requirement to close deck doors led to sinking
Savage Ingenuity is shown partially submerged with its bow facing two empty tank barges on the Gulf Intracoastal Waterway. The inset photo shows water up to the second deck on the starboard side of the towboat.
Courtesy U.S. Coast Guard
Rapid downflooding through an open deck door caused a towboat to sink last year near Sulphur, La., according to the National Transportation Safety Board (NTSB).
Savage Ingenuity sank on Sept. 5, 2017, at about 0035 near mile marker 245 on the Gulf Intracoastal Waterway. All five crew escaped to the two-barge tow, but the towboat sustained $1.3 million in damage. Almost 12,000 gallons of fuel also entered the waterway, most of which was not recovered.
NTSB investigators cited “the absence of company procedures requiring the closure of weather deck doors at all times while the vessel was underway” as the probable cause of the sinking.
“The tow was maneuvering about perpendicular to the strong eastbound current at the time it began heeling. Given the vessel’s low freeboard, water washed onto the main deck, reaching the sill of the open engine room door, and downflooded into the engine room,” the NTSB said. “Once water continuously flooded into the engine room, the list increased, and the engines stopped operating. The flooding overwhelmed the towboat’s reserve buoyancy, causing the vessel to sink.”
Savage Inland Marine, which owns the 1,880-hp towboat, issued a statement that disputed some of the NTSB findings. The company, based in Midvale, Utah, argued that strong currents stemming from heavy rainfall, along with the actions of an assist boat, should have been included as causal factors.
About an hour before the incident, the 68-foot Savage Ingenuity received orders to bring two empty 297-foot tank barges, SMS 30010 and SMS 30012, to the Calcasieu Refinery six miles away. The barges were arranged side by side facing west, and they needed to spin 180 degrees to head east toward the refinery.
Weather conditions were clear and calm, but the waterway had a 4- to 6-knot current due to recent heavy rain from Hurricane Harvey. These conditions required an assist boat to spin the tow in the strong current. The triple-screw, 1,800-hp fleet boat Alfred P. Cenac III served as the assist vessel.
The relief captain helming Savage Ingenuity and the pilot operating Alfred P. Cenac III made arrangements to “top around.” The maneuver involved backing Savage Ingenuity and two tank barges off the bank, then pushing the barges back into the bank to serve as a pivot point, according to the NTSB.
Alfred P. Cenac III helped pull the tow off the bank, and then took a position on the port quarter of the port barge and began pushing west into the current. The fleet boat pilot told investigators Savage Ingenuity heeled to starboard midway through the maneuver, causing the pilot to back off the barge.
An NTSB illustration depicts the sequence of movements by Alfred P. Cenac III as described by its pilot: (1) initial pushing position; (2) relocation to starboard side of the tow following Savage Ingenuity’s list to starboard and loss of power; and (3) approximate final positions of both towboats after the sinking.
Courtesy NTSB/Pat Rossi illustration
“When Savage Ingenuity began listing to starboard, the relief captain also stopped pushing on the barges and slackened the face wires by using the winch controls in the pilothouse, hoping that the vessel would return to an even keel,” the NTSB report said. “He told investigators that shortly thereafter the engines shut down and he heard the bilge alarm sound from the engine room. He then activated the general alarm to alert the crew of the emergency.”
At about this time, Savage Ingenuity’s captain awoke and went on deck, where he saw water rushing into the engine room. The relief captain later told investigators he did not realize the engine room door on the weather deck was “partly open.”
Savage Ingenuity’s crew escaped onto one of the tank barges and later boarded Alfred P. Cenac III. Salvage crews raised the towboat four days later. Although all of the doors and hatches were found closed once the vessel was brought to the surface, the U.S. Coast Guard noted that salvage divers had secured all of the doors and hatches, capped the vents, and placed bags over the stacks before Savage Ingenuity was lifted out of the water. The doors and hatches that divers found open were not specifically noted, the NTSB said.
Savage has procedures calling for all hatches to be closed while operating without barges in tow. But the NTSB said this policy did not apply during the accident maneuver because Savage Ingenuity had barges in tow. Savage has since updated its policies requiring that watertight and weathertight doors and hatches be closed while underway, and has included the changes in pre-departure checklists.
In its statement, Savage said the “historic rainfall” from Hurricane Harvey should be considered a “substantial causal factor” in the accident. The stronger-than-normal current necessitated the use of an assist towboat, and the company argued that the vessel’s actions also contributed to the sinking.
“The assist boat was positioned on the aft port quarter of the empty barges and began pushing Savage Ingenuity and the aft of its barges to starboard, into the prevailing current,” Savage said.
The NTSB report indicates that operators on both boats discussed the maneuver beforehand, but the agency does not specifically note whether the actions carried out by the assist boat matched the agreed-upon plan.
Al Cenac Towing of Houma, La., owns the 64-foot Alfred P. Cenac III. The company did not respond to an email message seeking comment on the case.