NTSB: Crew’s quick action limited fire damage to towing vessel Desperado

The Desperado spudded down in Lake Salvador after the fire. [Photo: US Coast Guard]

The crew’s swift action limited damage to the towing vessel Desperado when a ruptured hydraulic hose spraying fuel on a hot engine led to a fire aboard 1982-built vessel when transiting Louisiana’s Lake Salvador, the National Transportation Safety Board said Thursday.

The fire broke out in the engine room as the Desperado was transiting near Bayou Perot, La., on February 17, 2023.

“The three crewmembers aboard could not extinguish the fire with portable extinguishers. So they secured ventilation and fuel to the engine room and evacuated to a good samaritan vessel,” says an NTSB news release, that notes that “NTSB investigators concluded the crew’s prompt actions to remove the fuel and oxygen sources for the fire helped limit the fire damage and extinguish the fire. No pollution or injuries were reported and damage to the vessel totaled $30,000.”

According to the full NTSB report, the Desperado was a 59-foot-long lugger tugboat, a type of vessel specially adapted to serve inshore oil and gas rigs and other marine operations in shallow waters. It had an aft wheelhouse, an open foredeck, and two aft spuds to stabilize and anchor it.

Here’s what the full report says about the crew and their actions when the fire broke out:

“The captain, who was also the owner, had more than 30 years of maritime experience. Since 2010, he had served as captain on 21 inland towing vessels similar to the Desperado. The two deckhands … each had about three months of maritime experience, all on board the Desperado and under the tutelage of the captain.”

“About 1332, the fire alarm sounded in the wheelhouse, followed by the steering gear hydraulic tank low level alarm. The captain, who was in the wheelhouse, looked aft and saw smoke coming from the stern near the engine room centerline hatch. The two deckhands heard the alarm and reported to the wheelhouse. The captain hit the emergency stops for the two main propulsion engines, and the captain and deckhands ran down to the main deck to assess the situation. The captain saw thick black smoke coming out of the engine room centerline entrance door and determined there was an oil fire. He told the two deckhands to close the hatches and ventilation to the space.

“The captain then removed the cover from a semi-portable, 50-pound dry chemical extinguisher, prepared it for use, and proceeded to the engine room door. He attempted to put out the fire by discharging the extinguisher. However, he was unable to enter the engine room or proceed down the ladder to get to the base of the fire (which he believed to be above the port main engine) because there were flames near the top of the space overhead and there was heat exiting the space. The captain then closed the engine room door.

“Meanwhile, deckhand 2 closed the two starboard ventilation hatches (air intake and exhaust), while deckhand 1 closed the portside ventilation hatches (air intake and exhaust) to the engine room. The captain ordered the deckhands to secure the four emergency fuel shut off valves and to grab a portable handheld radio from the wheelhouse. Deckhand 2 closed the two starboard-side emergency fuel shut off valves and ran back to the wheelhouse to retrieve the radio. Deckhand 1 secured the two portside emergency fuel shut off valves and verified that the starboard-side emergency fuel shut off valves had been secured. These actions closed the valves below to the port and starboard diesel fuel tanks that supplied the propulsion engines and diesel electrical generator, stopping any additional fuel flow into the engine room. Electrical power stopped soon after the valves had been secured.

“The captain and deckhand 1 then opened the portside engine room ventilation hatch, and the captain discharged the semi-portable dry chemical extinguisher’s contents into the port side of the engine room. He discharged the agent in a sweeping motion from the engine room door until its contents were exhausted. However, the fire continued to burn. The captain closed the engine room door to seal off the engine space.

“With the fire still burning in the engine room unable to be extinguished, the captain determined that the crew should evacuate the vessel. After the captain verified that all hatches to the engine room were secure, he ran up to the wheelhouse and made a mayday call on VHF radio channels 13 and 16. US Coast Guard Sector New Orleans Command Center received and responded to the call. The captain relayed the Desperado’s location, and the Coast Guard launched a helicopter. The nearby crew boat Miss Jessica also responded to the Desperado’s distress call.

“The captain instructed the deckhands to grab their life vests and personal items. The crew boat Miss Jessica pulled alongside the Desperado to retrieve the crew shortly after the captain’s emergency call. All three crewmembers boarded the Miss Jessica, and the vessel moved upwind about a half mile away. They watched the Desperado as it drifted in a south-southwesterly direction due to the wind.

“About 15–20 minutes later, after the Desperado was clear of some hazardous pipelines that were marked with pilings and markers, Miss Jessica’s captain maneuvered back to the Desperado. The Desperado captain reboarded the vessel and dropped the port spud to anchor the vessel about 50 yards from some wetlands.

“At the time, no smoke was visible. The Desperado captain returned to Miss Jessica; the vessel transited through the Intracoastal Waterway back to the Tidewater Dock in Larose. Shortly after the Miss Jessica returned to the dock, a fire boat crew from Larose arrived at the Desperado’s location and determined that that the fire aboard the Desperado was out.”

PROBABLE CAUSE

The National Transportation Safety Board determines that the probable cause of the fire aboard the towing vessel Desperado was a hydraulic hose that likely exceeded its bend radius, eventually causing the hose to rupture, resulting in hydraulic oil spraying onto a hot engine exhaust manifold and turbocharger and igniting.

LESSONS LEARNED

Mariners and technicians who design, install, and maintain systems should follow the manufacturer’s guidance on the minimum bend radius for a hydraulic hose. The minimum bend radius is the radius below which an object cannot (or should not) be bent. Bending or flexing a hose to a radius smaller than the minimum recommended, or subjecting a hose to tension or torque, can place excessive stress on the hose and severely reduce the ability of the hose to withstand pressure. Tight space constraints may cause a hose to bend severely around corners. A machine or cylinder extending and retracting can also bend a hose. Hoses attached to moving parts may bend more than a hose in or near a machine’s stationary position. Actions to avoid hose damage or failure include clamping a hose in place to provide support, rerouting a hose assembly by installing fittings and adapters, and using a hose with more reinforcement (two braid instead of one braid).

• Download the full report HERE