The design of a new passenger ferry’s fuel oil return system and inadequate follow-on training for engineering crewmembers led to the 2022 fire aboard the Staten Island Ferry Sandy Ground, the National Transportation Safety Board said.
The fire broke out in the engine room of the Sandy Ground in New York Harbor with 884 persons aboard on December 22, 2022. The crew’s actions to contain and extinguish the fire, combined with a quick response from good samaritan vessels, resulted in the safe evacuation of all onboard. Damage to the vessel totaled $12.7 million.
As a result of the investigation, NTSB issued a safety alert and five safety recommendations, including recommended regulatory changes to design requirements for diesel engine fuel oil return systems.
Fuel Oil System
While attempting to manage fuel oil levels as the vessel was transiting between Staten Island and Manhattan, engine room personnel aboard the Sandy Ground closed both day tank fuel oil return isolation ball valves. This caused the overpressurization of the fuel oil system. The fuel oil filters on the main engines ruptured, leading to the spray of fuel oil that ignited a fire. A delay in shutting down the main engines led to fuel oil continuing to spray and increased the severity of the fire.
The Sandy Ground was the second of three Ollis-class ferries built for the New York City Department of Transportation and had been put into service six months before the fire. The Ollis-class ferries were not originally constructed with fuel oil return isolation valves. Instead, isolation valves were added after delivery to regulate the day tank fuel oil levels. The Ollis-class vessels did not have a means to relieve the pressure in the fuel oil return lines if both fuel oil return isolation valves were closed, and the relief valves in the fuel oil system did not have independent return lines. These design flaws led to the overpressurization.
The NTSB recommended the Coast Guard update marine engineering regulatory requirements to require diesel engine fuel oil return systems on U.S.-flagged vessels be designed to have either unimpeded return flow or a pressure relief valve. Until regulatory requirements can be updated, the NTSB recommends the Coast Guard develop and disseminate design guidance for new construction diesel engine fuel oil returns systems to have unimpeded flow from the engine or other arrangements to prevent overpressurization.
The NTSB made a recommendation that the American Bureau of Shipping propose the same design requirements to the International Association of Classification Societies.
Training
The NTSB also found the engineering crewmembers were not adequately trained on the fuel system for the new Ollis-class ferries. The crewmembers did not receive follow-on training after fuel oil return isolation ball valves were installed on the Sandy Ground. Unlike other Staten Island ferries, the new vessels did not have relief valves in their fuel oil return systems. The crewmembers likely thought the fuel oil system could not be overpressurized as relief valves prevented overpressurization on the other ferries. In addition, the engine room crewmembers on board the Sandy Ground each had a different understanding of the fuel oil system.
Safety alert
The NTSB is issuing a safety alert to vessel operators about the importance of understanding diesel engine fuel oil system return design and operation to prevent overpressurization of fuel oil systems. This is the second fire in two years the NTSB investigated in which overpressurization of the main engine fuel return system, caused by closed valves, led to diesel fuel spraying and igniting a fire. The other was a 2021 engine room fire on a towing vessel transiting the Mississippi River in Missouri.
Probable cause
The National Transportation Safety Board determines that the probable cause of the engine room fire aboard the passenger ferry Sandy Ground was the design of the vessel’s diesel engine fuel oil return system, which included isolation valves that could be regularly adjusted by the crew and, when closed, stopped return fuel oil flow from all operating engines, resulting in the overpressurization of the fuel oil system and the ignition of fuel oil spraying from ruptured fuel oil filters onto the exhaust manifold of a running engine. Contributing to the overpressurization was the operator’s inadequate training program on fuel oil system operation, which did not provide follow-on instruction after the installation of fuel oil return isolation valves at the day tanks.
Download the full report: NTSB: Sandy Ground Staten Island Ferry Fire
Download the safety alert: NTSB: Sandy Ground Ferry Fire Safety Alert
