The Day Safety Rules Paid Off
Gasoline flowing from pipeline break stopped by closing emergency valves required by Seattle F. D. on:
A potential disaster of enormous magnitude—a punctured 12-inch pipeline shooting thousands of gallons of gasoline 50 to 60 feet into the air in a metropolitan area—was averted in Seattle recently through a combination of prior safety measures insisted upon by the Seattle Fire Department and the knowledge of the responding department personnel.
Described as a “one-in-a-million” acoident, the entire incident was handled without a single injury or any property loss.
The potential holocaust began when a bulldozer operator cutting an access road for a new freeway took a large bite with his machine blade into what he thought was a stubborn rock. The “rock” was in reality the 12-inch Olympic Pipe Line. The right tooth of the bulldozer punctured the line and a stream of gasoline, at 300 psi, shot in the air. The hole was about 2 inches square.
A full response was immediately dispatched and at the same time the Olympic Pipe Line Company was notified to close all emergency valves.
The loss of approximately 7000 gallons of gasoline was less than the amount of fuel carried by one fully loaded railroad or highway tanker. It was well below the maximum estimate (10,000 gallons) Fire Chief Gordon F. Vickery had initially established for any “one-in-a-million-chance” break in the pipeline during safety requirement negotiations.
In late 1964, pipeline officials asked the Seattle Board of Public Works for a 25-year franchise to operate pipelines under Seattle streets. They proposed to move various petroleum products (primarily gasoline, but also diesel oil, stove oil and jet fuel) from two refinery sites approximately 60 miles north of Seattle through a 16-inch pipeline, at approximately 750 psi, to just south of the city to a pumping station.
At this point, the fuel would either continue along this 16-inch line to Portland, Oreg., or be diverted through a 12-inch pipeline at 500 psi to Seattle’s Harbor Island, where the area’s major storage tanks are located.
The pipeline company agreed to protect against electrolysis by taking cathodic readings along the line. Where necessary, counteracting electrical current would be introduced into the pipeline by means of wired connections. At the distribution station on Harbor Island, a 50,000-gallon slop tank was installed to hold fuel during a products interphase. The fire department insisted that automatic sectional pipeline control valves be provided.
Strict standards were established for all welders on the pipeline. Initially, it was planned to have each weld individually x-rayed. As the work progressed, the workmanship was so excellent that this requirement was lowered to approximately 50 percent of the welds. However, every weld passing under a city street or adjacent to a utility still required examination.
The fire department insisted that the 50,000-gallon slop tank be protected by a liquid foam system, that sufficient 20-pound potassium bicarbonate extinguishers be on hand, and that all electrical facilities within the center be explosion-proof. All equipment at the distribution center had to be designed so that it could be controlled by three separate means: handoperated locally, electrically controlled locally, and controlled from a location some miles away. In addition, an electrical control had to be mounted within 6 feet of the fence gate that would shut down the entire plant operation.
After the pipeline puncture, the department required all soil containing any possibility of flammable vapors to be removed—not less than 10 feet in any direction. The remaining soil had to be thoroughly flushed or neutralized. The cutting of the punctured section had to be done by “cold-cut” process only.
The break area to be repaired was required to be 100 percent inerted by complete stoppage of both ends of the existing line. In this case, dry ice packing was used. A reasonable waiting period was enforced before the product was permitted back in the line.
The break produced some significant conclusions:
First, the Seattle Fire Department’s goal of a maximum spill of less than 10,000 gallons proved to be a realistic figure, and the safety measures insisted upon by Chief Vickery were the primary factors in quickly containing the spill.
Second, the rapid dispatch of apparatus and the introduction of emergency measures by the supervising chiefs to control the flow of gasoline, coupled with the knowledge of the location of the important control valves, resulted in the immediate sealing off of the area until the danger had passed.
Admittedly this was a “one-in-a million-chance” accident—but it did happen. The safety requirements demanded by the Seattle Fire Department may have seemed excessively strict, but the results have proven them necessary.