Station 19, the newest fire station at Valero Energy's McKee refinery, is only the second of two stations on site. The number 19 signifies the number of firefighters who died 50 years ago in a tragedy at this Texas panhandle refinery that ranks in American history only three places behind 9/11 in total firefighter deaths.
A 15,000-barrel pumpkin-shaped spheroid tank containing about 500,000 gallons of mixed pentane and hexane caught fire that fatal Sunday morning in July 1956. The plant fire brigade and volunteers from nearby Sunray and Dumas responded to what evolved into a combination ground and vent fire.
"Obviously, there wasn't much or certainly not enough known about BLEVEs (boiling liquid expanding vapor explosion) back then," said McKee Fire Chief Mike Roberts. "While these gentlemen were actively fighting the ground fire and trying to control flame impingement, the spheroid BLEVEed."
Paying tribute did not end with the station's name. In April, Valero opened its doors to the public to dedicate the new station and commemorate the 50th anniversary of the disaster. Nearly 600 people attended the ceremonies, including four surviving spouses and other relatives of the firefighters killed.
The experience was more joyous than tearful, Roberts said.
"I felt like it probably was going to be hard on the widows but I've never seen more smiles or gotten more hugs and thanks in my life," Roberts said. "I think it actually gave them some kind of closure."
What came to be known as the Sunray disaster remains relatively unheard of today. Before the Valero ceremonies, the outstanding memorial to the event was a monument to volunteer firefighters on the grounds of the state capitol in Austin that lists the 11 Sunray and Dumas firefighter fatalities beside those from a more famous Texas fire disaster -- Texas City in 1947. However, that memorial does not list the members of the refinery fire brigade who were lost.
July 29, 1956
What we know for certain about that day is that terrain and design proved to be the critical factors. First, flammable hexane and pentane vapors escaped from the spheroid designated as No. 199. An article in the Oil and Gas Journal speculated about a line break, pump leak or even the popoff vents at the top of the tank.
"The first part is pretty unclear," Roberts said. "Back then, all spheroids vented to the atmosphere. Anyway, the relief valve released and when it did it turned pentane loose to the ground."
In 1956, McKee was only a 20,000-bbl refinery, situated 11 miles from Dumas, population 8,000, and seven miles from Sunray, population 1,500. The NFPA Quarterly reports that the tank farm was well spaced, with individual dikes for the various floating roof, cone roof, spheroid and noded spheroid tanks. Contents ranged from crude oil to finished products. A highway bordered the tank farm on the south side while nearly 500 feet separated it from the refinery process area.
Unfortunately, that 500 feet was on a slight downhill grade.
"The vapors of both pentane and hexane are considerably heavier than air," the NFPA article states. "With air equaling one, the vapor density of pentane is 2.49 and for hexane, 2.975."
Helping the vapors along was a light southwest wind, unusually mild for this windy region. The wind was blowing toward the process area, specifically an asphalt tank about 350 feet away under which a small fire was kept. At about 5:45 a.m. vapors ignited, then flashed back to No. 199.
For the next hour firefighters would be occupied with both a ground fire involving a liquid spill from a possible line leak in the vicinity of the tank's pump inside the dike and a fire at the gauging device and vents, the NFPA article states. Eventually, flames from the dike fire rose 40-feet high, enveloping the spheroid.
No. 199 was one of two identical tanks designed for 15 pounds-per-square-inch working pressure built in 1940, the article said. Each of these spheroids was equipped with two 6-inch pressure-vacuum vents set at 15 psi connected to an 8-inch vent and tee connection. Both vents were equipped with return bend weather hoods which effectively acted as U-joints, directing anything escaping from the vents downward.
"In case of vapor ignition at the vents, as occurred in this case, there would result a direct flame impingement onto the top of the tank in the vapor space," the article said.
Tank gauging records show that there were 28 feet, seven inches of product in the 46-foot-high spheroid, or approximately 12,000 barrels. A decision was made to begin pumping out No. 199, increasing that vulnerable vapor space, Roberts said. Slowly, the potential for a BLEVE increased.
"The plant fire brigade was severely limited in manpower since the fire occurred early in the morning when the number of available men for fire fighting was at the minimum," the NFPA Quarterly states. "For this reason assistance from the volunteer fire departments of Dumas and Sun Ray (sic) was requested."
Bob Hamilton, a reporter for the Moore County News, entered the refinery against advice from the sheriff and plant guard. He reported that two groups of firefighters were attempting to approach the spheroid from opposite sides while a third group cooled nearby exposures. Three fire trucks were present.
"I was standing about 200 yards from the tank and took pictures but it was too hot to talk to people," Hamilton said. "It felt like my face was up against an open oven."
According to the NFPA Quarterly, the refinery brigade laid in a hose line from a fire hydrant in the process area to their foam truck.
"They attempted to use foam to extinguish the ground fire but experienced considerable difficulty due to the intense radiated heat," NFPA Quarterly states. "It was reported that they were attempting to lay in longer foam lines prior to the rupture of the spheroid. The Sun Ray (sic) Fire Department laid in a water line on the downhill side of the tank farm and the Dumas Fire Department laid in a line from the upper side. All hose lines were approximately 900 feet in length."
Dumas and Sunray firefighters used the water available to them to keep adjacent tanks cool. Observers noted that hose streams were placed on a cone roof tank about 150 feet away from the burning spheroid. Another hose line was seen being used to protect a floating roof tank containing gasoline also about 150 feet away from the fire. It was also reported that a water line was used at least once on No. 199. Seal fires on adjacent floating roof tanks were promptly extinguished.
Hamilton wrote that a loud, roaring flame about 50 feet high spouted from a vent atop the burning spheroid. Flames from a ground fire were also intense. Firefighters were preparing to move closer with additional equipment when the alarm was sounded to evacuate. The rising heat had become too much, forcing firefighters to even abandon cooling the other tanks.
"At 6:53 a.m., or slightly over an hour after the original fire was reported, the top of the spheroid ruptured violently," states NFPA Quarterly. That the spheroid lasted an hour surprised some since LPG vessels exposed in a similar manner had ruptured in as little as 15 minutes.
BLEVE is a phenomenon often misunderstood, even by experienced firefighters. The textbook definition refers to a condition in which a chemical stored as liquid develops a gaseous vapor above it. Any rupture releases an overpressure of vapor inside. A sudden drop in pressure causes violent boiling of the liquid, refilling the vacant space with a terrific new overpressure of vapor. Such a significant overpressure of flammable vapor destroys the vessel containing it.
However, in this case flames somehow impinged on the pressurized vapor space above the spheroid's liquid contents. Since metal loses its tensile strength when heated, a bulge likely developed in the spheroid caused by the pressure inside. Any impingement below the vapor space would have been sufficiently cooled by the liquid contents. Emptying the spheroid of product merely increased the vulnerable vapor space. Even with the relief valve open, the pressure inside would have been sufficient to cause a rupture or BLEVE at the point of impingement.
"The flame impingement on the exterior tank surface from the burning vapors issuing from the vent discharge points and possibly from the ground fire caused the metal shell of the spheroid to stretch and eventually fail due to the internal pressure in the tank," NFPA Quarterly states. "The metal thinned out near the weld on the top (head-plate) over a distance of about one-third the circumference of the spheroid at this point."
The top of No. 199 was sheared by the force of the internal pressure release but landed within the tank dike.
"The remaining sections of the spheroid were also completely destroyed but likewise remained within the diked tank area," NFPA Quarterly states. "The entire venting assembly landed outside the dike." Investigators found the 8-foot-high gauging device about 700 feet away.
Hamilton's boss, news editor Bill Lask told the AP he heard multiple explosions that were not sharp, but more like the big thud of a fireworks rocket. This was soon followed by an ear-numbing concussion of the BLEVE.
"I watched in disbelief as a bright orange mushroom of flame boiled up, floating in heavy black smoke, and I prayed that the fire fighters would get out alive," Lask said.
Out of the billowing smoke, people were racing in all directions, Lask wrote. Some were human torches. Others did not get the chance to run. They simply crumpled where they stood, their lives snuffed out by the initial blast. All of the immediate dead were found within 400 feet of the spheroid. Sixteen firefighters died at the scene with another three dying later from burns. Thirty-two others not so close, including many of the spectators on the highway nearly a quarter-mile away, escaped with injuries.
Many of the dead and injured were personal friends, Lask said.
The fireball from the ruptured spheroid raised havoc throughout the tank farm. It ignited a 20,000 barrel diesel oil tank 200 feet away which contained 6,500 gallons at the time. Also ignited were two 10,000 barrel tanks of crude oil, containing 6,000 to 8,000 barrels in one and 2,000 barrels in the other. These tanks were 450 and 550 feet from No. 199. All three tanks were cone roofed with flame arresters on the vents, NFPA Quarterly reports. Yet other tanks that were closer did not ignite and suffered relatively little damage. The Oil and Gas Journal identified these tanks as having floating roofs.
"The coned roof tanks had a vapor space above the product that presented a danger," said IFW publisher David White. "By contrast, the floating roof tanks allow no vapor space."
An 80,000 barrel floating roof containing gasoline located about 225 feet away had two seal fires that were extinguished. A sixth tank smoldered but was also extinguished. The heat blistered the paint on company houses 3,000 feet away. A workman protected in a shack 300 yards from the first explosion was scorched. Two bulldozers were destroyed by fire almost 1,200 feet away. The blast also ignited a railroad trestle 1,250 feet away and small piles of lumber along the railroad tracks in the refinery area. Leaves on trees a mile away showed damage.
The heat was like someone trying to burn your face off with a blow torch, Hamilton said. Flames were everywhere. He started running and did not stop to take another photograph until he reached the highway. For others, that wasn't far enough.
"Everyone around me was running into a plowed field to get farther away from that inferno," Hamilton said. "One was a boy about 11 (actually 13). He didn't have a shirt on and his back was burning. He was in terrific pain and was almost hysterical."
Another man's hair was smoldering, Hamilton said. Then the reporter realized his own hair was on fire. He filed his story with the AP from the hospital.
One source estimated that the contents of the spheroid was dispersed to such a degree that it burned out within 10 minutes. Trying to reach the scene, Lask pushed to within an eighth of a mile of the explosion before the heat forced him back. He met survivors stumbling in the opposite direction.
"Some were sobbing with the pain of burns," Lask reported. "I remember two men, moaning in smoldering shreds. They crawled into the bed of a pickup truck and were taken to a hospital."
While the written record is spotty, an excellent photographic record of the disaster exists, said Roberts.
"A gentleman from Sunray who was a photo buff drove out that morning and sat on the highway taking pictures," Roberts said. "His son gave me the originals. Among them is a sequence of three shots -- one of the fire before the explosion, then a perfect picture of the explosion itself followed by a shot about 10 or 12 seconds after the blast. The fireball is the biggest I've ever seen in my life."
Judging from aerial photographs of the disaster an area almost three-quarters of a mile had burned inside the refinery, Roberts said.
Neither Dumas nor tiny Sunray were geared for the aftermath of a disaster this size, the Dallas Morning News reported.
"But (Dumas) is a country town, and everybody helps everybody else," the newspaper said, "and by 11 a.m. -- less than four hours after the disaster, all of the 32 burned had been taken care of in the previously quiet and calm 40-bed red brick Moore County Memorial Hospital."
Later that day outside assistance began pouring into the area. National Guard personnel carriers and ambulances arrived on the scene. An airport crash truck responding from Amarillo Air Force Base was used to protect the floating roof tanks, extinguishing at least one seal fire. Emergency responders arrived from Amarillo and Dalhart. There was little that could be done save for protecting remaining exposures.
"They controlled the ground fire as best they could but basically they let the fire burn itself out," Roberts said. "That was about the only option they had at that point."
In the early evening, a high wind from the south was blowing flames from two large tanks still burning away from the tank farm. Amarillo Fire Chief Roy Hill, quoted in the Dallas Morning News, noted that a wind shift to the north could create a dangerous situation. Fortunately, the remaining tanks burned out the next day with no further incidents. The refinery was back in operation that same day.
Then came the funerals.
"I have a neighbor who was alive at the time," Roberts said. "She talks about how groups like the women's auxiliaries would set up at the local churches and spent nearly two weeks doing nothing but getting the families to the funerals and cooking them three meals a day."
The NFPA Quarterly article published several months later cited the Sunray disaster as "another case which condemns the widely accepted practice of locating tank vents on pressure tanks in such a manner as to permit flame impingement on a tank's vapor space. It also made note of the following:
? Installation of a fixed water spray system on all pressure storage tanks would eliminate most of the hazard of a tank rupture by keeping the metal cool.
? If for any reason it is impossible to apply cooling water, all personnel should be removed at least 1,000 feet from the fire and, even at that distance, should wear protective clothing.
? Locating direct-fired heaters downhill from a volatile flammable liquid storage tank places an ignition source within the possible path of vapor travel.
? Cast iron should not be permitted in any flammable liquid piping, valves or connections.
? Pumps should be placed outside of a diked area to avoid exposure to fire.
? Installation of adequate fire mains in tank farms is necessary for fire fighting operations.
With the dead buried, life goes on. With each passing year the memory of the price paid at the McKee refinery faded into history a bit more. Then, half a century later, somebody asked Mike Roberts what he was going to name his new fire station.
NEW OWNERS, OLD BUSINESS
Today, McKee refinery has a throughput capacity of 170,000 barrels a day. McKee produces conventional gasoline, RFG, CBG gasoline and low-sulfur diesel that meets government specifications for on-road use. The refinery has access to crude oil from northern Texas, Oklahoma, southwestern Kansas and eastern Colorado via a 1,083 mile network of crude oil pipelines.
Expanding along with the refinery is the fire brigade. The new station is 175 feet by 150 feet with room for three drive-through fire truck bays. McKee's brigade of 63 firefighters -- all volunteers -- operate with a fleet that includes a 5,000 gpm Pierce industrial foam pumper, a Mack 1,250 gpm pumper and a Mack 1,250 gpm foam tender.
When it came time to name the station, Roberts consulted some of his fellow fire chiefs as to any guidelines or protocol involved.
"One of them replied in a way that got my wheels turning," Roberts said. "I went to my plant manager and told him what I wanted to do and why. I didn't want to give the company a black eye but history is history. I told him that I wasn't doing this for the company or for me, but for the survivors of the firefighters who died."
The manager, Bill Wuensche, supported the idea. He contacted corporate headquarters who gave him and Roberts permission to run with it. Station 19 was born. But the idea didn't end there.
Entering Station 19, the first impression is that it is a museum. The entrance opens into a small area reserved as a memorial to the Sunray disaster. Nineteen plaques, each bearing the name of a fallen firefighter, adorn the wall. Inside a glass case are photographs of the fire and explosion, together with faded newspaper accounts. Also added is a group photo of the 21 relatives who attended the dedication ceremony in April.
Addressing the crowd, Wuensche gave a broad summary of the events that occurred fifty years earlier. History had been slipping away, he said, so Valero believed it was only fitting that there be a permanent memorial at the refinery.
A duplicate of the individual plaques honoring the firefighters was presented to the appropriate family. Atop each was the Maltese Cross, a firefighter's badge of honor. Roberts read aloud a history of the cross and then closed the ceremony with the Fireman's Prayer.
"After that there wasn't a dry eye in the house," Roberts said.
Following that, Valero treated the visitors to dinner. Gifts honoring the relatives did not end there. Each family received an 8-inch by 10-inch copy of the group photograph and an album with 50 other shots taken during the ceremonies. A copy of the album is included with the permanent memorial.
Working together, Gov. Rick Perry, State Rep. David Swinford and State Sen. Kel Seliger added the crowning touch to the ceremonies. A resolution honoring the 50th anniversary of the Sunray disaster and the dedication of the new fire station was introduced and passed by the Texas Legislature. Accompanying the resolution was a Texas flag flown over the state capitol building on April 19, and sent by airplane to McKee for the ceremonies that same day.
The original plan was to place the flag directly into the glass enclosed memorial at the fire station. But one of the widows made a special request.
"She asked if I planned to ever fly the flag over the new station," Roberts said. "I made a deal with her. On July 29, the official 50th anniversary of the disaster, I will run the flag up to full staff, then lower it to half staff for the rest of the day. Then it goes straight into the glass box on the wall."