An Engineering Investigation of a Recreational Trailer Explosion at Tannehill State Park, Alabama

摘要

The paper details the investigation of a recreational vehicle explosion, the risk from using propane cooktops without a flame safety feature, and remedies to prevent similar reoccurrences. The trailer was inspected. All propane appliances with the exception of the cooktop incorporated flame failure devices (FFDs) which shut off the flow of propane if a flame is not present. All of the propane appliances were tested and found to operate normally. One burner on the cooktop was on, indicating it was the source of propane. The lack of a positive propane shut-off mechanism in the absence of a flame led to the explosion. The propane was tested for odor, and one of the cylinders was shown to have de-odorized the gas. Odor fade is a known phenomenon, and likely occurred in this case due to rust in the cylinder. The propane detector was tested and found to be working. However, it did not warn the occupants of a leak before the explosion. A review of applicable standards showed that flame failure devices were not required in cooktops for the recreational vehicle industry. Several manufacturers supplying valves with FFDs, and which were in compliance with ANSI Z21.15 were identified. These stovetops were available to both the RV and marine industry as early as 1993, and were adopted as requirements by the marine industry. Two commercially available valves were tested on an exemplar RV cooktop and found to work seamlessly with the existing hardware. Flame-out conditions were simulated, and both valves shut off the flow of propane in under 12 seconds.