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ROBERT BURKE
Published: July 1996

Also See: Propane/LPG Sidebar

Just before dawn, the early morning quiet of March 4, 1996 was interrupted by the sounds of crashing metal and burning propane in this East-Central Wisconsin farming community. At the North end of town, near an industrial area, 37 cars of a Wisconsin Central Railroad train derailed. Among the 37 derailed cars were 7 tank cars of highly flammable liquefied petroleum gas (LPG), 7 tank cars of highly flammable liquefied propane gas, and 2 tank cars of sodium hydroxide, which is a non-flammable corrosive material. Initially, as a result of the derailment, three of the tank cars opened up and the propane and LPG immediately caught fire. The characteristics of this incident are similiar in many respects to previous incidents that occurred in Waverly, Tennessee, and Crescent City, Illinois, the outcome in Weyauwega however, was much different. In the Waverly incident a propane tank car exploded from a boiling liquid expanding vapor explosion (BLEVE). It was cold when the train derailed in Waverly, just as it was in Weyauwega, however, two days into the Waverly incident the temperature started warming up. This caused an increase in pressure in the tank car which had been damaged in the derailment. The BLEVE occurred when the tank could no longer withstand the increasing pressure. Crescent City experienced a similiar incident to Weyauwega in that several propane tank cars derailed in the center of town. Resulting fires impinging on the tanks caused the propane tanks to BLEVE resulting in injuries to response personnel, bystanders and wide spread damage to the community.

Courtesy Robert Burke

The derailment in Weyauwega occurred at approximately 5:55 a.m. the wind was calm and the temperature was about 30° F. Twenty-Four volunteer firefighters from the Weyauwega Fire Department were on the scene within five minutes led by Assistant Chief Jim Baehnman. (Fire Chief Gary Hecker had left town on vacation just a few days before the incident occurred. He returned the second week of the incident but left Assistant Chief Baehnman in command of the incident). The Weyauwega fire department has two pumpers, engine 917 with a 1250 gpm pump and engine 913 with a 750 gpm front mounted pump. The department also has two tankers, one with 1200, and the other with 3500 gallons of water. Additionally they have a brush rig and a rescue/equipment van that was used as the command post. Several days into the incident, the Pierce Fire Apparatus company in Appleton sent a brand new 1500 gallon pumper to assist in the firefighting efforts.

Upon arrival, Chief Baehnman took command and immediately established the incident command system. The derailment had blocked the rail crossing on Mill Street and Chief Baehnman had a difficult time determining what was happening on the North side of the tracks. Fires were burning, with large fireballs 200 to 300 feet high and visible at times 13 miles away. It appeared that there were three separate fires. The first was a large fire fed by a damaged tank car at the intersection of Mill Street and the railroad crossing. The second fire involved the feedmill some 75 yards to the east of the crossing. The third fire was approximately 75 yards to the west of the crossing and involved a storage building. It is believed that the third fire resulted from fallen power lines caused by the derailment. Many of the fires burned for most of the 18 days however, unlike Crescent City, Illinois and Waverly, Tennessee, no explosions, (BLEVEs) occurred involving the propane or LPG tanks. It is believed that the cold temperatures and the snow on the ground may have contributed to the lack of explosions by helping to keep the tanks cool, although the exact reason is still a mystery. The lack of explosions accounted for the relatively small amount of damage that occurred within the town. Damage though extensive, was confined to the property of the feedmill, which was destroyed along with a storage shed. A residence to the north of the derailment site and one business experienced some heat damage. The estimated loss to the feedmill and surrounding property is 25 million dollars.

Upon sizing up the situation Chief Baehnman realized that the incident was beyond local capabilities and notified dispatch to request assistance from neighboring communities, the state of Wisconsin, and Region V EPA. Ten neighboring fire departments from Navarino, Iola, Scandinauia, Manawa, Clintonville, Mukwa, Fremont, Waupaca, Poysippi, Tustin, and New London, responded to Weyauwega's call for assistance bringing 22 pieces of fire apparatus and over 200 firefighters. Radio communications quickly became a problem because of the volume of traffic from all of the responding agencies. Additionally agencies from the private sector as well as the state and federal governments responded including, Region V EPA from Chicago, Wisconsin Department of Natural Resources (DNR), State Emergency Management, the governors office, Wisconsin National Guard, State EPA, the Federal Railroad Administration, Red Cross, and Salvation Army.

The first responding firefighters from Weyauwega found a tangled mass of railcars, broken rails, and a large volume of fire. The derailment occurred near a feedmill and the spreading fire was already impinging on feedmill structures and several grain and propane vehicles. Initial efforts were focused on fighting the fire in the feedmill and protecting exposures. The firefighters were lucky to the extent that a building across from the feedmill had not received its spring shipment of fertilizers and pesticides. Had the fire reached this building it could have added additional hazardous materials complications to the incident. A cheese factory just one block south of the burning tank cars had anhydrous ammonia pipes on the roof of the building. If a BLEVE had occurred the pipes could have been damaged by flying tank parts causing an ammonia leak.

The responding firefighters view of the incident scene was initially obscured by the large volume of fire and darkness. They were unaware of the tank cars of hazardous materials that were involved in the derailment and subsequent fire. Reports from first responding firefighters are conflicting as to the exact time it took to recognize that the burning tank cars contained propane and LPG. Time estimates range from 10 minutes to 1 hour. Wisconsin Central Railroad personnel advised the firefighters that the construction of the tank cars would allow them to withstand fire for approximately 1 1/2 hours. When this information was received it was already one hour into the incident. Once firefighters realized that there were propane and LPG tanks involved in the derailment, and they were on fire, a decision was made to pull back. Firefighters abandoned hose lines in the streets when they realized the seriousness of the situation. The abandoned hose lines were later damaged when they froze and were driven over by clean-up and restoration personnel during the incident. Temperatures during the incident ranged from daytime highs of +15° F to +30° F to nighttime temperatures of -5° F to +15° F. As the incident progressed the weather forecast was for warmer temperatures that would cause the pressure to increase inside the derailed tanks. Much like the increased pressure that occurred in Waverly, Tennessee that caused the BLEVE of one of the rail tank cars there. This forecast of warmer temperatures caused concern for the crews and helped confirm the need to hot tap the remaining cars before this dangerous pressure increase could occur.

Firefighters were fortunate that no explosions (BLEVEs) occurred involving the propane and LPG tanks before the decision was made to move to a safer location. The National Fire Protection Association (NFPA) says that BLEVE times range from 8 to 30 minutes, with the average being 15 minutes. The initial evacuation of personnel was two blocks for the first hour, this initial distance was then expanded to 7 blocks and finally to 1 1/4 miles. The Department of Transportation Emergency Response Guidebook (ERG) under guide 22 for propane and LPG recommends an evacuation distance of a minimum of 1/2 mile if propane or LPG tanks are on fire.

In addition to pulling back response personnel, Chief Baehnman ordered the evacuation of the entire city. Next to the Centex Gasoline Station, less than 100 feet from the derailment, a tractor trailer truck driver slept through the entire derailment and initial emergency response efforts. An attendant at the gas station had to awaken the truck driver to tell him to evacuate. Fire, police, and EMS personnel made notifications of the evacuation by going door to door while the local radio station provided additional announcements. As each residence was evacuated it was marked with a yellow tag so that other emergency responders would know the building had been cleared. Approximately 1700 people were evacuated from Weyauwega and another 600 from surrounding rural areas. Sirens and the Emergency Broadcast System (EBS) were not used for the evacuation. Most people, once notified, evacuated using personal vehicles. Two nursing homes with over 200 total patients were evacuated and taken to a hospital and other nursing facilities in nearby communities. Evacuation of the nursing homes was conducted by the staff of the homes with the assistance of EMS emergency response personnel. The evacuation was facilitated using buses from the local school district for ambulatory residents and ambulances for those unable to walk on their own. The evacuation of the nursing homes was completed in approximately two hours. Once the city was completely evacuated Chief Baehnman made the decision that no emergency response personnel would enter the city to fight any fires that may break out from the derailment or other causes.

Courtesy Robert Burke

Residents of Weyauwega that were displaced by the derailment and fires were directed to an evacuation center that was set up at a former gym in Waupaca 7 miles away. However, many of the evacuees opted to stay with relatives or in hotels, some as far as 30 miles away, which were provided by the railroad. Pets were not considered in the initial evacuation. As the incident progressed more and more citizens became concerned about their pets that were left behind. Chief Baehnman did not feel that rescuing pets was worth the risk to personnel and the public. So the decision was made that no pet rescues would be conducted. Chief Baehnman was later overruled by the governor and the pet rescue was conducted on a limited basis over the objections of the incident commander. After one week the National Guard was activated. Once on the scene, one of their initial efforts was to conduct a rescue of pets in a small portion of the city farthest from the incident. The pet rescue created additional problems as business owners then wanted to go in to check on their property. Eighteen days after the derailment occurred, the evacuated residents were allowed to return to their homes, after all danger from the burning propane and LPG tanks had diminished.

There were no injuries to emergency responders or residents directly resulting from the derailment. One resident suffered an elbow injury from a fall during the initial evacuation however, she was able to continue evacuating on her own. Another resident had a heart attack upon returning home, her home was not damaged and the heart attack was not attributed to the incident. Assistant Chief Jim Baehnman said "from the start of the incident, the tone of the incident would be driven by safety and not time". This approach and the fact that no BLEVEs occurred very likely accounted for the lack of injuries to response personnel, civilians, and the minimal loss of property.

The railroad did not have a hazardous materials team but immediately sent an operations supervisor to coordinate railroad activities with the incident commander. Five hazardous materials teams responded to Weyauwega from Oshkosh, Waupaca County, Appleton, Stevens Point, and Brown County. The first team arrived on the scene within one hour after the derailment occurred. Because of the potential dangers of the burning propane and LPG tanks the hazmat teams were assigned an advisory role in the beginning until the contract companies hired by the railroads arrived on the scene. Once EM Tech was on the scene they worked closely with the incident commander, the hazmat teams, the railroad and environmental agencies to determine the best course of action based on the condition and positions of the propane and LPG tank cars.

Security and traffic control were provided by the local police and the Waupaca County Sheriffs Office. Once the evacuation had been completed, law enforcement personnel were stationed at all roads into the city and did not allow anyone back in without the knowledge and consent of the incident commander. Police patrols made periodic entries into the evacuated area to ensure that no one had gone back in and that the homes and businesses were secure. Fresh snowfall on the second day of the incident provided a means for law enforcement personnel to detect breaches of security of the evacuated area. The air space within 10 miles of the derailment was restricted to reduce curiosity flights and to control the news media, this distance was reduced to 5 miles the fourth day of the incident. Superior Environmental and the national guard provided helicopters for aerial surveillance to locate spot fires and determine the extent and effectiveness of the evacuation. For the first few days after the incident, aerial photographs were the only means of viewing the incident scene.

The railroad had conducted previous exercises with other communities on this type of incident using the incident command system. The railroad brought in hazardous materials clean-up experts from EM Tech and Hulcher Professional Services from Denton, Texas, and Superior Environmental from Appleton, Wisconson. When it was determined that the last remaining propane tank would have to be vented and burned, an explosive expert from Louisiana was brought in also. Upon reaching the derailment site EM Tech and all other personnel took two days to study the site and determine the safest actions to take based upon the remaining tanks that were involved. Aerial photographs were used to make tactical decisions after EM-Tech arrived on the scene. Many of the tank cars were severely damaged in the derailment. Two of the cars were upside down and buried with only 10% of one and 20% of the other showing above the ground.

The actual "emergency" response phase of the incident only lasted until approximately 10:45 on the day of the derailment. Evacuation of the city had been completed by this time along with the relocation of response personnel to a position past the command post, which was now 1.25 miles from the derailment scene. The firefighters were also displaced just as other people evacuated from the town. The Fremont Fire Department shared their quarters with Weyauwega firefighters until they could return to their own quarters. At this point, the focus turned to stabilization, clean-up and restoration of the incident scene, which took the next 17 days to accomplish. The emergency response personnel assumed a role of support for EM Tech and other contractors during the process of stabilizing the burning and damaged tanks. Unmanned monitors were placed into service on the 3rd day of the incident as the pressure fires subsided and 6 or 7 of the propane and LPG tanks still had minor fires burning. Off loading of the tank cars was not undertaken because it was unknown what the extent of damage was to the cars. After carefully evaluating the derailment site, the decision was made to "hot tap" some of the propane and LPG cars to transfer the remaining fuel to a burn pit where it was allowed to burn off. The outer cars were tapped first and tapping moved inward until the last car was reached which could not be hot tapped due to its position. Hot tapping is a procedure that has been used successfully for many years in the chemical and petroleum industry but has limited applications in tank car accident situations. The process involves the welding or securing of a tapping to a vessel (such as a tank car), while it still contains gases or liquids. The tank is then drilled through a valve attached to the tapping fitting. A special drilling machine is used which threads the valve and reduces leakage. Once the drill bit penetrates the vessel wall the drilling machine is removed from the valve. Product can then be pumped or drained from the tank car through the valve. Hot tapping should only be attempted by trained and experienced contract personnel, this is NOT an emergency response function.

Because of the potential danger to personnel, tanks containing certain commodities should not be hot tapped. They include: acetylene, ethylene, ethylene oxide, halogens, elemental sulfur, hydrocarbons in stainless steel tanks, cryogenics, hydrogen, acids, oxygen, and tank cars operating at below atmospheric pressure. Once the tank is tapped, nitrogen is injected into the tank forcing the liquid through the tap valve to a flexible hose connected to a pump and then into a burn pit through a hard pipe. The liquid is burned off until the tank is empty. It is the process of hot tapping and "flaring" that took the most time in the stabilization process. Fire department personnel stood-by with charged hose lines and rescue equipment to protect the contract personnel performing the hot tapping and flaring operations. Personnel from EM Tech said "they had never experienced an incident with circumstances that were as difficult or as large as Weyauwega". Assistant Fire Chief Jim Baehnman, the incident commander, indicated that "the total amount of liquefied gases involved was over 1 million pounds, which is reported to be the largest incident ever in the United States in Terms of volume". Because all but 10% of the last remaining tank car was showing above ground, the decision was made to vent and burn the tank car. Charges were placed on each end of the tank opening it up to allow the remaining propane and LPG to burn freely. Venting a tank involves the placing of shaped explosive charges on the high end and low end of a damaged tank car. The resulting explosion opens up the tank car and allows the product to drain out and burn.

Courtesy Robert Burke Click On Image For Full Size

Resources were not a problem during the incident and those needed were obtained promptly with everyone cooperating; "everyone knew just what to do". One of the main problems encountered initially was obtaining the necessary number of telephones to complete the calls to deal with the incident. The local phone company brought in 40 lines by noon on the first day of the incident.

Initially power was cut to about 15% to 20% of the homes in the area to control ignition sources immediately around the derailment. The natural gas service was also cut to the community and as a result up to 95% of the homes did not have heat which caused water pipes to freeze in many homes and businesses. The freezing was not as severe as first feared and only about a dozen homes were severely damaged. The main natural gas feeder line into the community ran directly under the derailment site next to Mill Street. Responders were concerned that the line may have been damaged as a result of the derailment which prompted the decision to shut down the line.

The news media was briefed each day between 0800 and 0900. As the days passed the residents were constantly wanting to know when they would be allowed to return to their homes. Noon briefings were held each day in three locations to update the evacuated citizens on the progress of the incident. Evacuees were notified by the news media that the briefings would be conducted in Appleton, Waupaca, and Stevens Point. The incident commander used examples of the Waverly, Tennessee and Crescent City, Illinois derailments to illustrate to the people what can happen when propane and LPG tanks BLEVE. This type of information helped people to understand whey they couldn't go back to their homes before it was safe to do so.

During and after the incident maintenance problems were experienced with fire apparatus that had been constantly idling for almost three weeks without being shut off. The primary breakdowns involved motors and electrical generators on the motors.

Cause of the derailment was thought to be a switching gate that malfunctioned or a section of broken rail. The accident is under investigation by the National Transportation Safety Board (NTSB) and a report should be out by the end of 1996.

Related:

• Propane/LPG Sidebar
  
• HazMat Studies Archives
  
• The Street Chemist