A significant hydrogen leak occurred during refueling of the onboard hydrogen storage tank of a fuel cell-powered lift truck while it was completely depowered. The in-tank shutoff solenoid valve had recently been replaced, and this was the initial refueling event after the replacement. The fuel zone access panel was removed to allow constant visual leak checking with Snoop leak-detection fluid. The event occurred during the final pressure testing of the repaired system when an O-ring failed at approximately 4500 psi, releasing the entire contents of the hydrogen tank in about 10 minutes. The dispenser hose/nozzle was immediately disconnected, and the leak location was quickly isolated to the tank/valve interface. A 30-foot boundary around the lift truck was cleared of personnel and view more

A fuel cell forklift operator stated that he observed a "ball of fire" coming from the left side of the forklift that seemed to flash and extinguish. Investigators found no external signs of a fire, but the forklift would not start. The fuel cell power pack access panel was removed to enable investigators to search for any internal signs of a fire. Some areas inside the fuel cell stack appeared to have experienced an electrical arc or some type of overheating. All connections were verified to be tight and secure. The internal fuel cell stack circuit board cover was then removed, and the circuit card on top of the stack also showed signs of overheating. After the fuel cell stack circuit board was removed, a broken drill bit was discovered on top of the fuel cell stack plates. view more

The evaporator pad in a fuel cell power unit installed in a hydrogen-powered forklift caught fire during operation. The evaporator pad is used for wicking the product water created by the fuel cell. The operator dismounted the forklift, observed flames coming from the fuel cell unit, and called for help. The facility fire brigade used a fire extinguisher to put out the fire. The upper left corner of the fuel cell evaporator pad was burned entirely; the plastic bracket that holds the evaporator pad in place was distorted; there was some discoloration of the radiator. No injuries were sustained by the operator and no damage was sustained by the forklift.

The fuel cell unit continued to run during the incident, as did the onboard data acquisition device. Hydrogen concentrations view more

A fueler drove away without disconnecting the fueling hose from the vehicle. The breakaway did not open and the receptacle fitting sheared off the vehicle. Subsequent testing of the breakaway showed that the breakaway operated at 210 lbs, which was above the design value of 133 lbs. The hydrogen contained in the hose between the dispenser shutoff valve and the vehicle check valve was released.

DESCRIPTION: On a Friday afternoon in 2007 a traffic accident occurred at the corner of two urban streets. Two vehicles were involved. Each vehicle contained a single driver (no passengers). Vehicle 1 was a Fuel Cell Vehicle. Vehicle 2 was a conventional Toyota Camry. Vehicle 1 was traveling west, approaching an intersection with a green light, and proceeded into the intersection. Vehicle 2 was traveling north on a cross street. The driver of Vehicle 2 incorrectly perceived a green light and proceeded into the intersection. The vehicles collided in the intersection.

RESPONSE: The police were coincidentally in the area and able to respond quickly to the site. The vehicles were moved out of the intersection. Vehicle 1 (fuel cell vehicle) shut down upon impact and was pushed out of view more