Solvents With Low Flash Point Ignite, Wrecking Modern Fish Oil Processing Plant

Editor’s Note: The following account of a violent and costly explosion— in point of lives and property lost, marks another page in the record of catastrophies involving products and processes peculiar to the age in which we live—call it ‘chemical,’ ‘atomic’ or what you will.

Although in point of casualties and property damage, this Seattle explosion cannot compare either with the Los Angeles metalworker perchloric blast with its 17 dead, of February, 1947, or the Texas City holocaust with its hundreds of fatalities of that same year, it is nevertheless interesting to students of fire control and prevention as indicative of some of the peculiar post war hazards with which today’s fire service must contend.

The editors are proud to present this exclusive and comprehensive account, told by the man most capable of reporting it—Fire Chief William Fitzgerald of the Seattle Fire Department, who directed operations at the scene.

SHORTLY after 5:30 P.M. on July 6th, 1948, a blast, described by some as of “A-Bomb” proportions, brought death to four men and destroyed the fish processing and meat rendering plant of Lyle Branchflower, Inc., located at Shilshole Avenue and 15th Avenue Northwest, Seattle, Washington. The explosion was followed immediately by a huge black plume of smoke lighted by solvent-fed flames, which leaped high in the air.

Hundreds of windows in industrial plants and dwellings throughout the area were shattered by the blast, which rocked the entire north end of the city and was heard more than ten miles away. Debris and portions of the interior of the wrecked structure were found over two miles distant.

Four men, all of the occupants of the building at the time of the explosion, were killed. Fortunately, less than an hour before the explosion thirty-five of the plant’s employes had left the premises, otherwise the loss of life would have been far greater as it is difficult to see how anyone could have survived the shattering blast that tore the modern concrete and steel plant apart.

The Plant and Processes

The Branchflower plant went into operation in the summer of 1944 and is reported to be one of the world’s leading producers of vitamin A products from fish livers. It is said that the firm processes 90 per cent of all halibut livers obtained by American fishermen along the Pacific Coast from Alaska to California.

Although processing is the company’s principal business, the plant also included a fat-rendering works for tallow production and a chemical research laboratory engaged in a study of oil feeding for livestock.

Shortly after it began operations, the plant became the target of criticism from citizens and commercial groups, which charged that its operation created offensive odors. After hearings before the Board of Public Works, an airpurification unit was installed to eliminate the odors.

It is reliably reported that the Branchflower Company and the Halibut Producers Cooperative, supplying agency of fish livers to Branchflower, were insured for $465,000 on buildings and equipment and $300,000 use and occupancy.

The Branchflower building was a modern reinforced concrete structure, three stories in height, 100 ft. x 100 ft. in area. Immediately west of the main plant is a dock and warehouse and on the opposite side of the canal is located Fishermen’s wharf. Adjoining the plant are tracks of the Northern Pacific Railroad and an 18-ton railway tank, the latter being ripped completely off its trucks and hurled on its side.

The blast completely demolished the Branchflower building, the force being so great that a 20-ft. square section of an 8-in. concrete wall was blown a distance of 90 feet from the building. The blast and fire seriously threatened the 15th Avenue West bridge, one of the principal arteries leading to the north end of the city.

The fire, which instantly followed the explosion, involved Shell Solvent A, a mixture of heptane and hexane used in the industrial processes. The flash point of this solvent is 40 deg. F.

The explosion was apparently caused by solvent fumes which were ignited by an open electric motor operating a skimmer pump in the fish processing plant.

Two processes were carried on in the building in separate portions of the structure, separated by a solid concrete fire wall. One involved processing fish and fish livers for extraction of oil and vitamins. This part of the plant was not the source of the explosion.

The second portion of the plant contained a process for extracting fat and tallow from waste meat and bone, the residue being processed for chicken feed. In operation, retort cookers of 180 cubic feet capacity were filled with waste bone and meat and cooked with steam at 475 deg. F. for a period of one to four hours. In the cooking process, the material was dehydrated by vapors passing out a vent to a jet condenser. When cooking was completed, the material was allowed to cool to 175 deg. F.

At this juncture, the condenser lead valve was closed and the solvent lead valve opened, and solvent introduced into the mass by pumping. Following this, cooking continued for one-half to one-and-one-half hours, a hydrometer being used to check the solvent for fat content.

When this process was completed, solvent was pumped into the settling tank for mechanical separation of the fat and solvent and allowed to stand for a 24-hour period. This tank was of approximately 1500 gallons capacity. The top was skimmed off this tank by pumping the fat solvent solution to a still to reclaim the solvent, then from the still to the condenser, then to a 2,000-gallon tank. This solvent wash process was repeated four times.

The residue left in the settling tank was then re-introduced into a retort cooker where it was pressurized and heated to 175-deg. F. to drive the solvent into a still for reclaiming. About 500 gallons of solvent was involved in this process. When this solvent is reintroduced into the tank, a 15-in. dome cover is usually left open until the retort is full, ready to start the processing. This was the situation when the workers changed shifts at 4:00 P.M., the day of the disaster. At that time the day man informed the assistant engineer coming on duty at 4:00 o’clock that the dome cover was open.

Apparently without closing the dome cover, the assistant engineer started the cooking process, which vented solvent fumes through the open cover and they escaped throughout the plant, finally concentrating in the lower levels, the fish meal room and fish oil storage vault. Subsequent investigation found the cover open and the cooking valves open, indicating that the cooking process had been carried on without closing the dome cover.

In some manner, probably as said, from an electric motor operating the skimmer in the fish oil section of the plant, an ordinarily non-hazardous area, the fumes were ignited and the terrific blast followed.

About 3,000 gallons of solvent are used in the plant every day in the working processes. The structure, as previously reported, was modern and built under permit by the Seattle Building Department, the plans and processes being filed at the issuance of the permit.

Radio Important in Operations

The first alarm was received by the fire department at 5:34 P.M.. from box 4314 at 14th Avenue Northwest and West 47th Street. This brought Engines 18, 35, 20; Ladder 8 and Chief 4.

The first arriving company officer immediately sounded a second alarm via radio from the company’s radioequipped apparatus. This was logged at 5:36 P.M., and was responded to by Engines 9, 11, 21; Ladder 6 and Chief 2. It also brought the Chief and Assistant Chiefs of Department.

At 5:50 P.M. a special call brought Engine Company 2 to the scene.

Radio played an important role in this crisis, as it does in all Seattle fires. The second alarm was radioed in before the arrival of the District Chief. By radio, also, the additional company was summoned, as were ambulances, additional police help, the coroner and line crews to cut down the “hot” electric wires.

Upon arrival, firemen found the plant completely demolished by the explosion and solvent involved in fire. Three workers on duty at the dock and warehouse to the west of the plant had been knocked down but miraculously escaped injury. They fled across the canal in a fishing boat. Three section hands of the Northern Pacific Railroad, standing less than 80 feet from the explosion also escaped injury.

Three of the victims were doubtless killed instantly, two being buried in the wreckage. One body was found clear of the wreckage and the fourth victim was blown sixty feet through a doorway onto the railroad tracks north of the plant, and critically injured.

The first-due company placed a 1 3/4-in. stream in operation, using 3 1/2 in. hose and two 2 1/2-in. hand lines. The second due company operated a 1 3/4 in. stream from two 2 1/2-in. lines siamesed into a deluge set. The special-called engine company placed a jumbo fog nozzle in operation to protect the threatened bridge structure, using 3 1/2 in. hose.

The other engine companies operated hand lines. Six of the seven engine companies responding hooked up pumpers, four tandem, two to a hydrant.

The first-due ladder company recovered one body which had been blown from the building by the explosion, and worked around the plant searching for other casualties. Company members found one man seriously burned and injured, rendered first aid, and dispatched the victim to the hospital by ambulance. He later died.

The second-due ladder company assisted engine companies in laying lines, there being no ladder work involved. Later they worked at overhauling and the recovery of bodies from the ruins.

The fire was knocked down by hose streams in 28 minutes, after which all water lines were shut down and the remaining fire extinguished by two portable foam nozzles.

Firemen were given considerable trouble when a power line dropped on a pumper. One fireman, R. J. Blucker, of Engine 10, suffered burned hands and shock. This occurred at the outset of the fire, the 4,400 volt line, having to be cleared from the pumper before the latter could go into action. Assistant Fire Chief R. B. Rogers also felt the effects of the charge and was sent home after treatment by Dr. Frank Maxson, fire department surgeon. One fireman, Bat Madigan of Engine 2, suffered back injuries by being thrown by a “wild” nozzle. He was hospitalized.

The property loss was estimated at $350,000. Explosion damage to structures in the surrounding area is not estimated at this writing.

Blast Wrecks Refinery and Kills Four at Seattle Four plant employees lost their lives when this halibut oil refinery exploded on July 6, and completely demolished the plant as indicated above. Flammable solvents employed in the processing of fish and animal oil provided the gas mixture which caused the explosion.

No posts to display