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.