Inspection Detail

Inspection: 122043458 - Briggs & Stratton Corporation

Inspection Information - Office: Milwaukee Area Office

Investigation Summary

Employee #1, a pot man with miscellaneous duties in an aluminum die casting operation, was attempting to extinguish an incipient fire caused by an overflow of molten aluminum at a die casting machine holding pot. The furnace and holding pots are manufactured by Linberg/MPH, Riverside, MI. The three die casting machines are made by Lester with Walniak fronts. The automated die casting cycle functions in the following manner: An inclined conveyor feeds aluminum ingots up and into an electric melt furnace. From the furnace, the metal flows by gravity into an adjacent holding reservoir and then into a covered, heated trough, which in turn feeds three laterals to the three die casting machines. At each of the die casting machines is a holding pot of molten aluminum that is auto ladled into the die casting machines. The holding pots are equipped with adjustable float rod sensors that govern the maximum and minimum levels in the melt furnace by controlling the amount of conveyor feed into the furnace. On this day, float/sensor failure at the first die casting machine is suspected, as this is the lowest point on the gravity-fed system. As a consequence, the conveyor failed to shut off and the high molten metal level in the furnace overflowed the holding pot at the first die casting machine, creating an incipient fire and setting off a ceiling sprinkler head. Employee #1 attempted to use an extinguisher. He fell over, lost consciousness which he never regained, and died on September 14, 1995. It was noted that the holding reservoir next to the furnace had the relief spout clogged with solidified aluminum, nullifying its intended function of preventing a higher than preset molten metal level by discharging excess metal into a crucible. The condition could have been averted had the holding reservoir relief spout not been circumvented from operating. Also, a more effective preventive maintenance program is needed, as a bent float/sensor rod was discovered at the first die casting machine.

Keywords: HEART, UNCONSCIOUSNESS, INADEQUATE MAINT, WORK RULES, FIRE, EQUIPMENT FAILURE, CARDIOVASC DISEASE, MECH MALFUNCTION