The initial discovery of the problem with the vessel's propulsion system occurred when the Barberi's chief engineer went up to the pilothouse after the collision.
The engineer found that even though the pitch levers were in the neutral position, the propeller pitch indicator for the New York-end unit read out 50% thrust.
This indication was confirmed by the stream of water that was being pushed away from the stern of the vessel.
The chief engineer then unsuccessfully attempted to bring the propulsion unit to zero pitch using the pilothouse controls.
Control of the propulsion units was transferred to the engine room, where the crew used the units’ local controls to bring the pitch to zero.
When the crew later attempted to back the Barberi out of the terminal using these local controls, both propulsion units functioned normally.

On May 10, 2010, NTSB inspectors attempted to replicate the problem with the pilothouse controls.
Because the vessel was docked during the testing, the units were tested without the engines running.
Hydraulic pressure to the units was supplied by electric standby pumps, which limited the maximum attainable pitch command to 75%.
When a full ahead pitch command was input from either pilothouse, both units responded normally.
When a neutral pitch command was then input, the Staten Island end propulsion unit responded normally to the command, while the New York end unit remained locked at 75% thrust.
When control was subsequently transferred to the engine room, both propulsion units responded normally to commands.

The investigators then turned their attention to the New York-end's propulsion control panel.
In this panel, electric solenoids were used to shift hydraulic valves.
These valves sent hydraulic oil to the control cylinders on the propulsion units, shifting the pitch setting of the units.
The panel was removed from the vessel and sent to the NTSB's material laboratory.
Upon disassembling the ahead/astern solenoids on the panel, investigators found bronze ring fragments.
These ring fragments had lodged themselves in the solenoids, preventing their correct operation.
Due to the nature of the damage that the rings had sustained, NTSB investigators were unable to determine why they had originally fractured.
The initial discovery of the problem with the vessel's propulsion system occurred when the Barberi's chief engineer went up to the pilothouse after the collision. The engineer found that even though the pitch levers were in the neutral position, the propeller pitch indicator for the New York-end unit read out 50% thrust. This indication was confirmed by the stream of water that was being pushed away from the stern of the vessel. The chief engineer then unsuccessfully attempted to bring the propulsion unit to zero pitch using the pilothouse controls. Control of the propulsion units was transferred to the engine room, where the crew used the units’ local controls to bring the pitch to zero. When the crew later attempted to back the Barberi out of the terminal using these local controls, both propulsion units functioned normally.
On May 10, 2010, NTSB inspectors attempted to replicate the problem with the pilothouse controls. Because the vessel was docked during the testing, the units were tested without the engines running. Hydraulic pressure to the units was supplied by electric standby pumps, which limited the maximum attainable pitch command to 75%. When a full ahead pitch command was input from either pilothouse, both units responded normally. When a neutral pitch command was then input, the Staten Island end propulsion unit responded normally to the command, while the New York end unit remained locked at 75% thrust. When control was subsequently transferred to the engine room, both propulsion units responded normally to commands.
The investigators then turned their attention to the New York-end's propulsion control panel. In this panel, electric solenoids were used to shift hydraulic valves. These valves sent hydraulic oil to the control cylinders on the propulsion units, shifting the pitch setting of the units. The panel was removed from the vessel and sent to the NTSB's material laboratory. Upon disassembling the ahead/astern solenoids on the panel, investigators found bronze ring fragments. These ring fragments had lodged themselves in the solenoids, preventing their correct operation. Due to the nature of the damage that the rings had sustained, NTSB investigators were unable to determine why they had originally fractured.
MV Andrew J. Barberi