HAZ-MAT EMERGENCIES INVOLVING INTERMODAL CONTAINERS
BY GREGORY G. NOLL, C.S.P.
Intermodal freight and tank containers are becoming a common sight in all modes of transportation. Although similar to traditional types of freight and tank containers, they present several differences that can pose unique challenges to public safety and industrial responders.
BACKGROUND
The basic principle of an intermodal container is to have a transport vehicle that can be physically moved on more than one mode of transportation–e.g., from ships to trucks to railcars to fixed facilities. Intermodal containers are constructed to standard international designs. Common designs include freight or box containers and portable tank containers.
Use of intermodal containers in North America increased during the 1970s, when the United States began to be used as a “land bridge” for international traffic between the Atlantic and Pacific oceans. Under this service offered by the railroads to various ocean shipping companies, a container initially loaded in Europe and en route to the Far East would travel via container ship to the U.S. East Coast, be loaded on a train for the trip across the continental United States, and then be reloaded on another container ship on the U.S. West Coast for its ultimate destination in Asia.
In the 1980s, the use of intermodal containers became more prevalent for domestic transportation, particularly for box containers and their cousin, the piggyback trailer. Today, more than four million intermodal containers are routinely used to ship hazardous and nonhazardous materials throughout the world. This increasing use of intermodal containers has also created new problems for public safety and industrial emergency response personnel.
Freight containers are used to transport hazardous and nonhazardous nonbulk packages. Configurations include dry vans, refrigerated units, open-top containers, and flat containers. They can be found on marine vessels, as containers on flatcars (COFCs) in railroad transportation, and attached to the trailer chassis during highway transportation. In addition, they may also be found at fixed facilities, where they are used for short-term storage.
DESIGN AND CONSTRUCTION FEATURES
The most common intermodal freight container is the dry van, which is used for transporting a wide range of regulated and nonregulated materials. From an emergency response perspective, they share many of the same concerns presented by vans and tractor trailers.
Key construction features of intermodal freight containers include the following:
Container. Freight containers are commonly found in two lengths–20 and 40 feet, although containers as long as 45, 48, and 56 feet may also be found. In some countries, however, containers may also include 10- and 30-foot lengths. All ISO containers are eight feet wide. In addition to the standardized length and width, ISO also specifies standardized heights ranging from eight to 912 feet.
The 8 2 8 2 20 intermodal freight container is used as the basic measuring stick in many statistical comparisons. This container is referred to as a “TEU,” meaning that it is a 20-foot equivalent unit. The term “FEU”–which refers to 40-foot equivalent units–may also be used.
Door designs and the number of locking assemblies on intermodal freight containers vary widely. Doors may have two-, three-, or four-latch bar assemblies. Although fairly common in Europe, side doors are typically not found on containers in North America.
Materials of construction. Freight container designs are either smooth-side containers, external-post containers, or corrugated-side containers.
Smooth-side containers are generally made of aluminum or fiberglass-reinforced plywood (FRP). Aluminum smooth-side containers are constructed of a number of panels with interior posts riveted to them, whereas the FRP containers have no visible rivets or corrugations. Most of these containers are unvented. Vented smooth-side containers can be identified by a series of small holes along the top or bottom of the side panels.
External post containers have a number of posts riveted to the outside of the container. They are typically constructed of steel or aluminum. Vented external-post containers can be identified by the small rectangular panels usually found near the corners of the container sides.
The corrugated container, which has become the most common, is usually constructed of steel with sides consisting of a number of welded corrugated panels. These external corrugations may be a flat, square design or beveled with the corrugations angled or nearly rounded. Most of these containers are vented; the vents appear as small rectangular panels and are near the corners of the container`s sides or as the filler between the corrugations.
Corner castings. Supporting frames for all intermodal containers (freight containers and portable tanks) are built with corner fittings commonly referred to as corner castings. They are used to secure the container and lift it with standard container-handling equipment. Corner castings must conform to ISO Standard 1161, Specifications of Corner Fittings for Series Freight Containers. Cast-iron corner castings are prohibited.
OTHER TYPES OF FREIGHT CONTAINERS
Refrigerated containers. “Reefers” are very similar to dry freight containers, but they have a refrigeration unit mounted on the container`s nose or front end. The refrigeration units may be flush-mounted or exposed. Some insulated containers may also have clip-on refrigerated units attached to the container`s front face so that the container can be used for dry or “chill frozen” cargo. Cryogenic liquids, such as liquid nitrogen, are commonly used as the refrigerant (see photo on page 66, left).
Most refrigerated freight containers are not provided with their own power source. External power source options include a ship`s power source, a plug-in at a fixed facility, a chassis-mounted generator for highway use, a freight-car generator, a generator container, or a temporary clip-on generator. It is not uncommon to find 220- or 440-volt power supply cords being used to supply refrigerated COFCs when being transported by train.
The most common design for reefers is the smooth-side container constructed of aluminum or FRP. Insulation materials include polyurethane or polystyrene foam, mineral wool, and fiberglass. The insulation and refrigeration unit decrease the reefer`s internal cubic capacity in comparison with that of dry freight containers.
Flat containers. These containers are used for transporting heavy machinery, large containers, and other special equipment not capable of being transported in a box intermodal or other enclosed container. Flat containers may be a straight platform with no bulkheads or may have a fixed or collapsible bulkhead.
Open-top containers. These freight containers consist of four sides; are generally constructed of steel or aluminum; and have an open top, which is enclosed by a canvas-like tarp. Open-top containers are used for transporting loose or granular materials and items that are too large for fully enclosed containers.
CONTAINER MARKINGS
Box container markings and placards are critical elements in (1) identifying the hazardous materials involved and (2) evaluating the hazards and risks. Container markings can include the following:
Reporting marks and number. All containers must be marked with reporting marks and a container number. The initials indicate ownership of the tank, and the number identifies the specific container. These markings are generally found on the right-hand side of the tank (as you face it from either side) and on both ends.
Country, size, and type markings. The container will display a country, size, and type code. The country code (two letters) indicates the tank`s country of registry. The following four digits indicate the ISO size/type code.
The ISO country code indicates the country of registry for the container. However, responders should note the following disclaimers. First, the country of registration can vary within a company`s container fleet. For example, Evergreen Marine has containers registered in the United States and Panama. Second, the country code may not always appear on the container.
The ISO size/type code indicates the container`s size and other specific container features. The first two digits indicate the container`s length and height; specific sizes are assigned specific numbers. The second pair of digits is the ISO type code. Specific types of containers are assigned specific numbers, such as “00” for a closed dry van container, “10” for a vented dry-van closed container, “20” for an insulated container, “32” for a refrigerated container, “51” for open tops, and so forth.
Markings and placards. Freight containers and trailers must be placarded in accordance with DOT and IMO regulations. Which placard is used depends on the hazard class, the quantities of hazardous materials being transported, and the mode of transportation.
Some specific situations responders should be aware of regarding the placarding of international shipments include the following:
–Containers loaded with regulated commodities that exceed regulatory thresholds must display the appropriate DOT placard to correspond with the commodity`s classification. Any additional placard authorized by the International Maritime Dangerous Goods Code (IMDG) should also be found [see 49 CFR 172.502(c)(1)].
–The required placard must meet the DOT placard design specifications. For example, an INFLAMMABLE placard would not be legal in lieu of a Flammable Liquid placard, even though they are identical in size, color, and intent.
— It is not uncommon to find hazard class terms (e.g., Flammable Liquid) written in a foreign language.
ADR/RID marking system. The European Agreement Concerning Transport of Dangerous Goods by Truck (ADR) and European Agreement Concerning Transport of Dangerous Goods by Rail (RID) are used within Europe for the movement of portable tank containers. These regulations are in line with the IMDG requirements and are used to assist emergency responders in safely identifying the contents of a hazardous-materials transportation container or vehicle. Intermodal tanks and containers shipped into the United States and North America may contain these markings. (See sidebar on page 65.)
HIGHWAY TRANSPORTATION–EMERGENCY RESPONSE CONCERNS
Although listed under highway transportation, a number of the issues listed below pertain to all modes of transportation.
Emergency responders have encountered numerous problems in dealing with intermodal freight containers and tractor trailers containing hazardous and nonhazardous materials that do not require placarding (remember the 1,000-pound rule!). Shipping documents may refer to these shipments as “freight of all kinds” (FAK) and may not accurately reflect what is inside of the container.
Hazardous materials shipments originating outside of the United States can sometimes create problems in clearly identifying (1) who the shipper is and (2) who the emergency response point-of-notification is within the United States. Although this situation has improved with the DOT Emergency Response Communication regulations, responders still can encounter problems in quickly accessing a knowledgeable individual who can provide accurate information on what is inside a freight container. In some instances, the U.S. point-of-contact has been a shipping broker who has little or no knowledge of the container`s contents. If in doubt, start with CHEMTREC.
While the majority of shippers and intermodal carrier companies are very reputable, there are also those who “live on the edge”–both operationally and financially. Haz-mat enforcement and motor carrier inspections have consistently found problems with the mechanical integrity of equipment as well as inadequate vehicle and trailer maintenance (e.g., brakes, connectors, and so on).
Improper loading procedures–which can range from poor blocking and bracing to improper load separations between reactive chemical families and hazard classes–sometimes cause haz-mat emergencies. It is not uncommon to find that the last row of containers was “wedged” or pushed by a forklift into the freight container so that the container doors can be closed. Normal movement and vibration during transportation can place mechanical stress and eventually cause container leaks and spills. (Of course, the container that is leaking will never be at the back of the container!)
Intermodal carriers, particularly those operating in port and terminal areas, will typically make multiple runs during a one- to four-week period. Several public safety HMRTs have experienced incidents in which the driver had copies of the shipping papers in the truck cab for all runs during the preceding month. If the driver is seriously injured or hospitalized, it may take an extended period of time for emergency responders to gather, review, and determine which are the proper shipping documents.
The ADR/RID marking system assists European emergency responders in identifying the contents of a hazardous-materials transportation container or vehicle. Since intermodal tanks and containers shipped into the United States and North America may contain these markings, emergency responders should have a basic understanding of this system.
Some emergency responders refer to incidents involving intermodal freight containers as “surprise packages,” because you`re never quite sure what you will have until you open the doors. In this regard, freight containers pose the same concerns as vans and tractor trailers. Remember the following safety practices:
–NEVER stand in front of freight container doors when opening the container. Unlock the door. Using ropes or pike poles, stand off to the side as the container doors are opened. If anything goes wrong, responders will be off to the side and out of the high-hazard area. For example, loads may shift and come rolling out as the doors are opened. A 55-gallon drum of water weighs approximately 465 pounds, and most corrosives and other chemicals weigh in excess of 500 pounds. Insulated freight containers can be very tight. Opening the container doors and allowing the outside air to mix with the inside reactive environment may result in an explosion.
–If the freight container or trailer is completely loaded, it may be extremely difficult to identify which container is leaking and the source of the problem. In this case, responders will have to perform “container triage”– inspecting, removing, and separating the containers one by one until the leaker can be identified.
–Forklift trucks or other container-handling equipment may be required to perform the container triage process. If the container or trailer is intact, evaluate the hazards and risks involved in moving the vehicle to another location where it will be easier to manage the problem (e.g., off the highway onto an adjoining road, to an isolated area of a truckstop, to a state highway maintenance area, and so on).
–If a freight container has been involved in an overturn situation, forcible entry may be required. When dealing with noninsulated containers, the easiest entry points will be through the (1) doors (sliding vs. swinging), (2) roof, (3) walls, and (4) floor. Remember that the walls may have metal or wood sheeting on the interior and that the floor is the strongest structural element of the trailer.
RAILROAD OPERATIONS–EMERGENCY RESPONSE CONCERNS
Containers on flatcars (COFCs) and trailers on flatcars (TOFCs) are the two most common railroad shipments found today in the United States. COFCs can be found on trains in various configurations, including single and double stacks. The containers are attached to the flatcar through twist-lock attachments (i.e., corner castings), similar to those used with truck chassis. Stacking cranes and container lifters are the most common methods of placing COFCs on trains at rail terminals.
TOFCs are normally loaded on a flatcar by a stacking crane–a spreader is attached to the container`s top corners, and the trailer is lowered onto the flatcar. Container forklifts and container lifters can also be used to lift a trailer onto a flatcar; however, not all trailers are designed to be picked up in this manner, and there are specific lifting points on the trailers. Although not as common, ramps (i.e., “circus ramps”) may be available for driving the trailer onto the flatcar. The trailer is attached to the flatcar by locking the trailer`s kingpin to a fifth wheel assembly built on the flatcar.
There are no Federal Railroad Administration (FRA) restrictions specifying which regulated materials may be shipped in COFCs and TOFCs, although there may be individual railroad restrictions. Cargo tanks cannot be shipped as a TOFC on a flatcar.
1. Remember the basic clues and their priority for identifying intermodal containers:
container shapes,
markings and colors,
placards,
shipping papers and related documents, and
senses.
The consist will be the primary shipping document for railroad transportation and will be in the possession of the train crew. When dealing with TOFCs and COFCs, the consist will provide the following:
Number of the flatcar.
Number of each trailer or container being transported on the flatcar.
Description of each hazardous material being transported within the trailer or flatcar. For example, the consist description for a single UPS trailer on a flatcar may be several pages long, with the required shipping paper entries for each hazardous material.
2. The latest generation of deep-well flatcars allows up to four 20-foot containers to be double-stacked. While these flatcars allow for the movement of more containers, they also create potential problems for emergency responders, including the following:
If the COFCs on the bottom tier are placarded, the placards may be covered by the flatcar framing and not be readily visible to emergency responders.
Depending on how the COFCs are loaded, it is often not possible to open the container doors without removing the container from the train. Upper-tier containers may be loaded “back-to-back” and be approximately 25 feet high, whereas the doors on the lower-tier containers will be inaccessible due to the flatcar`s deep-well framing.
3. Flatcars containing COFCs may be connected in a series of three to five cars, sometimes referred to as “three-packs” or “five- packs.” One central generator supplies electricity to support refrigerated or heated containers on these flatcars. The generator is usually fueled by approximately 500 gallons of No. 1 or No. 2 diesel fuel oil. Electrical power is then supplied to the flatcars by 220- or 440-volt lines running within the flatcars.
4. Haz-mat releases in COFCs and TOFCs may pose a number of challenges for emergency responders, including the following:
Trailers with swinging doors and loaded back-to-back will be difficult to open without removing the trailer from the flatcar. Even if the trailer has a rear rolling door, limited space will make egress extremely difficult.
Even if the doors are accessible from the rear of the flatcar, the door will be approximately seven feet abovegrade. A ground ladder will then be required to unlock the doors. As already stated, NEVER stand in front of the doors when opening the container. Once the doors are unlocked, ropes or pike poles should be used while standing off to the side as the container doors are opened. If anything goes wrong, responders will be off to the side and out of the high-hazard area.
If the TOFC is involved in a derailment or rollover situation, the fifth wheel attachment on the flatcar may fail. Even if it doesn`t fail, the lightweight construction of modern trailers may likely cause the trailer roof or sidewall to fail.
If forcible entry into a TOFC is required, the easiest access points will be through the (1) doors, (2) roof, (3) walls, and (4) floor. Remember that the walls may have metal or wood sheeting on the interior and that the floor is the strongest structural element of the trailer.
* * *
An intermodal container can be physically moved on more than one mode of transportation (e.g., from ship to truck to railcar). These containers not only are intermodal but also are constructed to standard international designs. Because intermodal containers are easily moved from one location to another, they are gaining acceptance as the container of choice for moving bulk products from one country to another.
The most common intermodal freight container is the dry van or “box” container. As the workhorses of the intermodal industry, they are used for transporting a wide range of regulated and nonregulated materials. From an emergency response perspective, they present responders with the same problems as vans and tractor trailers.
In Part 2, we will review intermodal portable tank containers. n
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Intermodal freight and tank containers are becoming increasingly common. This container ship is being off-loaded at the Port of Baltimore. (Photos by author.)
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A 40-foot corrugated freight container is loaded on a railroad flatcar in a container on flatcar (COFC) configuration.
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(Left) An example of a smooth-side refrigerated container with clip-on liquid nitrogen refrigeration unit. (Right) A flat container with fixed-end racks transporting uranium hexafluoride.
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An example of freight container markings. The initials identify the tank`s owner; the number, the specific container.
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(Top) An example of a trailer on flatcar (TOFC). (Bottom) COFCs can present unique forcible entry challenges for responders.
CODES, REGULATIONS, AND STANDARDS
Intermodal containers are designed, constructed, and handled in accordance with a number of codes, regulations, and standards, including United States, international, and foreign domestic standards. In North America, the most notable include the following:
International Maritime Organization (IMO). Sponsored by the United Nations, IMO is the major maritime organization for establishing safety standards for ships, their cargo, and operating systems. The primary IMO reference document for the transportation of hazardous materials and intermodal containers is the International Maritime Dangerous Goods Code (IMDG). Section 13 of the IMDG pertains to “Portable Tanks and Road Tank Vehicles” and defines the types of portable tanks, design and construction requirements, special product-related features, and inspection requirements.
Although the IMDG does not have the force of law, it was the first detailed specification developed by major international trading countries, and many countries have adopted it into their national standards and regulations. In addition, ocean carriers have adopted IMDG as the minimum requirements for marine transportation of hazardous materials.
U.S. Department of Transportation (DOT). Title 49 of the Code of Federal Regulations (49 CFR) covers the transportation of hazardous materials. Parts 170 through 179 define the types of portable tanks, design and construction requirements, special product-related features, and inspection requirements.
Any deviations from the DOT requirements require an exemption or special approval. If a portable tank container is issued an exemption, the exemption number will be stenciled on the side of the container (e.g., DOT-E34567).
There are some differences between the DOT and IMDG requirements, including shell thickness calculations and relief valve settings.
Transport Canada (TC). TC has promulgated the Transportation of Dangerous Goods Regulations, which governs the transportation and use of intermodal containers for haz-mat transportation in Canada. The respective Canadian provinces have either adopted these regulations directly or have adopted similar regulations of their own.
Association of American Railroads (AAR). AAR is a U.S. trade association for the railroad industry that also develops industry standards and guidelines. All portable tank containers accepted for transport on the railroad must meet the requirements of AAR 600, Specification for Acceptability of Tank Containers. All tank containers that meet these requirements are stenciled with “AAR 600” on each side of the container. AAR 600 is not law.
International Standards Organization (ISO). ISO standards cover the structural design of intermodal containers, thereby allowing for worldwide intermodal movement. ISO standards cover the corner casting design; dimensional design; racking and stacking requirements; and markings relative to size, strength, and identification. Although ISO is not law, it establishes the standards ships, trailers and chassis, and railcars use for intermodal transportation requirements.
Convention for Safe Containers (CSC). CSC is an international convention primarily intended to ensure that all intermodal containers (i.e., freight, tank, and so on) undergo regular inspections for structural integrity. Certain strengths, testings, and markings are included in the convention. CSC is referenced by DOT in 49 CFR Parts 450 through 453, and compliance is required by 49 CFR Part 173.32 b (c). n
ADR/RID MARKING SYSTEM
Also referred to as the “Kimmler System,” the marking system consists of two orange panels with black printing. The upper box contains a Hazard Identification Number; the lower box contains the four-digit United Nations identification number.
The Hazard Identification Number (upper panel) consists of two or three figures. The first figure indicates the primary hazard. In general, the figures indicate the following hazards:
1 Explosive
2 Emission of gas due to pressure or chemical reaction
3 Flammability (vapors) and gases or self-heating liquid
4 Flammable or self-heating solid
5 Oxidizing (fire intensifying) effect
6 Toxicity
7 Radioactivity
8 Corrosivity
9 Miscellaneous dangerous substance
X Reacts dangerously with water
NOTES
* Doubling of a figure indicates an intensification of that particular hazard (e.g., 33).
* Where the hazard associated with a substance can be adequately indicated by a single figure, the figure will be followed by a zero (e.g., 30).
The second and third figures indicate the secondary or tertiary hazards. In general, the figures indicate the following hazards:
1 Explosive risk
2 Gas produced in contact with water
3 Flammable risk
4 Molten state (elevated temperature)
5 Oxidizing agent
6 Toxic risk
7 Open
8 Corrosive
9 Self-polymerization, risk of spontaneous violent reaction
X Reacts dangerously with water
Examples
23 Flammable gas
236 Flammable gas, toxic
33 Highly flammable liquid (flash point below 21ºC)
X338 Highly flammable liquid, corrosive which reacts dangerously with water
40 Flammable or self-heating solid
55 Strongly oxidizing substance
559 Strongly oxidizing substance that can spontaneously lead to violent reaction
63 Toxic or harmful substance, flammable (flash point between 21ºC and 55ºC)
663 Highly toxic substance, flammable (flash point not above 55ºC)
90 Miscellaneous dangerous substance n
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FORCIBLE ENTRY TECHNIQUES FOR INTERMODAL FREIGHT CONTAINERS
Intermodal freight containers can transport various types of regulated and nonregulated materials. Hazardous materials may be found in nonbulk packages such as drums, pails, bags, or cylinders, as well as in bulk containers such as intermediate bulk containers (IBCs) or “totes.” If there is evidence of a leak or the interior contents need to be inspected for damage, open the box container. Obviously, the best way to gain entry is to open the door using safe entry procedures. However, when box containers are involved in an accident or rollover, the container can be crushed or collapsed to the point that its doors have become jammed.
When the container cannot be accessed through normal means, forcible entry is required. Unlike the smooth-side aluminum or fiberglass containers, the corrugated container can be very difficult to open if it is heavily damaged. The exterior walls are made from corrugated welded steel panels, and the interior structural members are well-braced. In short, corrugated steel containers are tough!
One of the fastest ways to gain entry to a damaged corrugated steel container is to cut through the side or roof with a power saw using a carbide-tip blade. However, saws cannot be used most times because sparks may cause a fire or an explosion. Remember that even if the risk of explosion is not present, saws can throw sparks into the interior space through the saw cut and ignite combustible packing materials. As a general rule, saws are not a good forcible entry choice for steel containers because of the risk from fire. Saws may be appropriate for cutting access holes into the sides or roofs of containers when a fire is involved. For example, when the container is loaded with Class A combustible materials (e.g., cardboard) and a smoldering fire needs to be extinguished, you can cut a triangular-shaped hole and place a handline through the hole to smother the fire before opening the container doors.
Hydraulically powered rescue tools are a good choice for forcible entry, because they minimize the risk of fire. Remember, however, that the rescue tool`s power plant is a potential ignition source when flammable liquids or gases are involved. When flammable liquids or gases are involved, place the power unit as far away from the container as possible to minimize the risk of fire or explosion. Standard hazard and risk assessment and site-safety procedures must be followed (e.g., monitoring, control zones, protective clothing, and so on).
Field tests and practical experience with hydraulic rescue tools have shown the following:
–Tools equipped with the typical automotive tips are often ineffective in forcing entry through the box doors. The wedge-shaped automotive tip is too large to spread the cargo doors open. When used to force the door`s locking rod open, the wedge tip either pulls the entire rod assembly from the box or rams the door further into the box.
–Tools equipped with a power cutter attachment have often proven to be the most effective method of forcing entry.
When forcing doors, secure them. Case containers may be resting against the inside of the doors. Options include chains or web straps with seatbelt-locking buckles. Once the lock mechanism is freed, the doors could swing open and the load could fall on the forcible entry crew. If the doors cannot be secured, brace or shore them up until forcible entry operations are completed and all personnel are clear of the rear doors. n
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Entry operations into freight containers can pose physical and chemical hazards for responders.
