Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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BACKGROUND OF THE IMVENTION
1. Field of the Invention
There have been several major tr~nsportation accidents in
the United States involving the release of hazardous chemicals,
followed by spectacular fires and explosions, dispersion of toxic
vapors, extensive property damage and potential ground water
pollution. In many of these incidents, there has been injury
to people and/or loss of human life. Property and environmental
damage has been estimated in the hundred~of millions of dollars.
Many of these catastrGphes have involved railroad tank cars and
tractor-trailer tank trucks transporting hazardous chemicals.
The transportation of hazardous chemicals in the United States
on railroads, roads, highways and waterways is regulated by various
agencies of the U.S. Department of Transportation, as well as
by state and local bodies. These agencies have instituted numerous
regulations to reduce accident ~requency, severity and public
impact. These regulations stipulate technological modifications
as well as operations and management changes in the transportation
of hazardous chemicals to provide safety to the public. For
example, one regulation requestes the carrying of bills of lading
or waybills identifying the chemicals being transported. The
railroads, for example, have become conscious of potential public
hazards and economic costs resulting from accidental chemical
releases, and have undertaken changes in operational procedures,
development o~ contingency plans, and have instituted emergency
response management procedures to cope with hazardous materials
accidents. Truck fleet operators also are considering various
operational measures to reduce tractor-trailer accidents involving
chemicals.
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Unfortunately, major transportation accidents involving
hazardous chemicals continue to occur. One of the major problems
associated with railroad accidents involving hazardous materials
in tank cars and their accidental release is the proper identiflca-
tion of the chemicals being transported. The National TransportationSafety ~oard and the National Fire Protection Association have
repeatedly pointed out that emergency response personnel need
immediate, accurate information concerning the materials involved,
and guidance in the handling of transportation emergencies lnvolving
hazardous materials.
The National Transportation Safety Board noted in a recent
investigation (NTSB-RAR-79-1) that "Fire fighters experienced
a forty-five minute delay in obtaining the waybills and consist
information with pertinent hazardous materials emergency information.
This delay could have had serious consequences, particularly if
they had attempted to fight the fire before the second explosion.
Fi~e fighters should have known immediately where to find the
train's hazardous materials information. Also, if the crew members
had been injured, a longer delay in obtaining the information
would have occurred. If the crew members had been killed or injured,
there was no identified location where the consist information
could be obtained from."
Also in 1979, in a train derailment in Mississaga, Canada,
lack of identification of the leaking chemicals for over eight
hours led to considerable confusion as to the proper emergency
response actions to be taken. Finally, after the chemical was
identified as chlorine, over 2507000 people were evacuated--the
largest evacuation due to a hazardous materials incident in North
America.
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The initiation of emergeney action in evaeuation of inhabitants
from potential hazard zones surrounding a train derailment involving
several chemical cars in Livingston, ~ouisiana in 1981 was also
delayed by several hours, to almost a day, beeause of the inability
of emergeney personnel to identify the ehemicals in the derailed
ears. Placards attached to the ears identifying their contents
were lost, and the car sequences were jumbled as a result of the
accident, making identification of contents extremely difficult,
even though the waybill for the train was available. There have
been several such incidents relating to highway and road trueks
in which the single major problem in initiating an emergency response
was the lack of knowledge of the eontents of the damaqed vehicles
on the part of first responders on the scene.
.
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2. Description of the Prior ~rt
At present, indirect methods are virtually the only means
- available for identi~ying the chemicals contained in tan~ cars.
These methods include: reading labels and placards; identifying
contents by sizet shape and type of container; reading package
or container markings obtaining and reading shipping papers;
contacting transportation personnel; contacting CHEMTREC (Chemical
Transportation Emergency Center); and utilization of existing
emergency guides, cards or manuals.
10In the rare cases in which a chemical has been released,
and appropriate measuring instruments are available to emergency
response personnel, a positive identification of the leading chemical
may be made. ~ut even in this case, the instruments may be useless
if multiple chemicals have been released, or if there is fire
or smoke obscuration.
Several of the indirect methods give information only as
to classes of hazardous materials and not the identity of the
specific chemicals involved. The new Department of Transportation
identification numbering system is intended to aid in positive
identification through placards; but this system has neither been
completely implemented on all tank cars and highway tank trucks,
n`or is the system failsafe in an accident. For example, the placard
numbers can be erased due to mechanical scraping in an accident,
or obscured by smoke and soot deposits in a fire. In many instances,
the placards are mechanically released ~rom the tank car structure,
and may lie far away from the accident. Heat or danger o~ explosion
may prevent close enough access to read identifying information.
~ills of lading may be unavailable, lost, or may indicate insufficient
information. In the case of multiple car derailments, the locations
of tank cars are invariably jumbled. This makes it very difficult,
if not impossible, to identify the cars from the train consist
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papers, which only list tank cars sequentially from the locomotive.
In the case of highway tank trucks, the placard s~stem leads to
confusion and possible erroneous response action when a tank truck
containing multiple chemicals is involved in an asciden~. The
partitioning of the tank truckg necessary to avoid a large free
surface liquid area allows these trucks to carry several different
cargoes, and to have several different placards. The indirect
methods of chemical identification are at best inadequate, and
at worst, lead to exacerbation of the catastrophe due to incorrect
identification and initiation of incorrect action. In short,
these indirect methods of chemical identification in an accident
are ineffective, and may pose potential hazards to emergency response
personnel.
Another problem with the placarding system presently in use
lS involves the lack of uniformity regarding placarding regulations
between the United States and its neighboring nations of Canada
and Mexico. Frequently, hazardous materials which are properly
placarded and transported within the United States are turned
back at the Canadian and Mexican borders when the placarding stan-
dards for the materials involved differ between the two countries.
Yet another problem with the present placarding system ist`he "open" nature of the system. This system allows terrorists
to easily identify dangerous or explosive chemicals being transport-
ed through populous areas, and could conceivably allow such terror-
ists to use such chemicals being transported to endanger largenumbers of the civilian population.
Active techniques of chemical identification available at
present are useful only if the chemical has been released. These
techniques are used for determining the concentration of the chemical
in the atmosphere, rather than for strict identification. Most
methods used in accident situations rely on remote sensing technol-
ogies which utilize electromagnetic radiation in one form or
another. Typically, the interaction between the particular
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chemical in the atmosphere and the radiatiorl emitted by a sensor
in the infrared, visible or ultraviolet region of the spectrum
is sensed. Identification principles are based on absorption,
emission or scattering of spectral characteristics of the radiation.
Many systems developed for air pollution studies use laser beams
as sources of high intensity coherent radiation.
Unfortunately, while these techniques work very well under
controlled conditions in a laboratory, their usefulness in the
field is limited by various practical, logistical and cost-related
difficulties, especially where unexpected and accidental chemical
release conditions are concerned. Many of these systems are bulky,
expensive, and not readily available at the accident site in a
timely manner.
A survey conducted by Gross et al in 1982 for the Federal
Emergency Management Administration of the actual experiences
of a group of emergency response workers, indicates that in 33
per cent of the accidents, the placards were not visible, and
in 52 per cent of the incidents, the manifest information was
unavailable on a timely basis. Furthermore, the survey indicates
that in the opinion of emergency personnel, while the quantative
information on the concentrations of hazardous vapors was deemed
desirable, the first priority was to identify the chemicals in
the tank cars. Most of the research work at present is focused
on developing more accurate methods of determining flammable or
toxic vapor concentrations in the air subsequent to a chemical
release, and not much effort (other than placarding) has been
expended in developing techniques for identifying the chemical
in its contained state.
1316584
SUMMARY OF THE INVENTION
The key questions facing the first emergency workers
on the scene at a hazardous materials transportation accident
involving a highway tank truck or multiple rail tank car
derailment and a chemical spill -include: 1) What are the
chemicals? 2) Are they hazardous, poisonous, toxic or
corrosive? and 3) ~re they flammable or likely to explode?
The rapidity of response and the nature of corrective actions
initiated, including evacuation and relocation of nearby
inhabitants, will depend very crucially on the proper
identification of the chemicals, knowledge of their physical
and chemical properties, and their behaviour in the
environment. The reduction of threat to life and property
will depend to a large extent on the initial corrective action
taken by emergency response teams arriving at the scene of a
transportation accident involving either the release or
potential release of a chemical. The corrective action has to
be proper and timely so as not to exacerbate the situation.
Many accident investigators have recognized the need for
reliable chemical identification in accidents. The National
Transportation Safety Board has repeatedly recommended that
both regulatory agencies and other institutions support
research efforts for chemical identification and for improving
procedures ar.d records on chemical consists in a train or
truck transporting hazardous materials.
It is a feature of one form of this invention to
provide an electronic remote chemical identification system
capable of delivering upon demand to emergency response
personnel information about the chemical being carried in a
particular tank car, tank truck, barge or ship, such as its
Department of Transportation chemical number, the chemical
name, the shipper or manufacturer's name, and even detailed
information as to the actions to be taken involving a spill of
the specific chemical.
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It is a feature of another form of this invention to
provide a chemical identification system for meeting all the
present standards of identification currently required, and
also precluding identification of the chemicals during
transport by groups such as terrorists who miyht have illicit
uses for such information.
According to one embodiment of the invention, the
system involves a transponder attached to each vehicle or tank
ear, which transponder is coded for the particular ehemieal
being transported by the shipper or manufacturer at the time
the ear is loaded, and a master inquirer unit used at the
accident scene to activate the transponder and decode its
information.
This same system can also be used during the normal
eommerce of transporting chemicals and commodities to identify
the eargo in non-accident situations. Further uses to which
this system can be applied include automatic classification of
tank cars in classification yards, position location of tank
cars, tank trucks or other vehicles utilizing a satellite-
mounted interrogator, and taking of surveys of passing trainsor truck traffic for statistical or regulatory purposes.
According to another aspect of this invention, there is
provided an electronic remote chemical identification system
eonsisting of a transponder unit for mounting on a eontainer
eontaining the ehemieal; memory and proeessor units associated
with the transponder unit the memory unit having both
permanent and programmable sections, the permanent seetion
eontaining a unique transponder identification number; an
eneoder unit for programming the memory unit with information
relating to the chemical in the container being transported,
the eontainer itself and other data; and a remote interrogator
unit for remotely interrogating the transponder unit to cause
the proeessor units in the transponder to eompare the data set
content of the interrogation with both the data set in the
permanent memory section and the data set in the programmable
memory section of the transponder and to encode a response to
9a ~ 316~8~
the interrogation only if the data seks match, and to transmit
the response.
In the above embodiment, preferably the electronic remote
chemical identification system is one in which the transponder
memory is programmed by the encoder with information rela~ing
to the chemical being transported, as well as additional data
necessary for appropriate responsive action should an accident
occur.
In the above system, preferably the remote interrogator
lo unit for remotely interrogating the transponder is one which
causes it to relay the information to the interrogator
includes means for decoding and displaying the information for
immediate use by emergency response personnel at an accident
site, as well as for use by supervisory personnel or control
e~uipment during normal transport of chemicals and other
ha~ardous materials in day-to-day commerce.
In a still further preferred embodiment, the electronic
remote chemical identification system described above is one
wherein the transponder comprises an antenna, a radio
fre~uency transmitter and receiver, a pulse generating
circuit, microprocessors, a programmable memory, a non-
volatile memory and a battery and associated solar powered
- charging circuit for powering the several elements of the
transponder unit; the interrogator unit comprised of
unidirectional and omnidirectional antennas, a radio frequency
transmitter and receiver, microprocessors, a programmable
memory, a non-volatile memory, a display means, and a keyboard
for data entry and program control, a sighting device and a
null meter, in which the interrogator unit is operable to
program the programmable memory of the transponder unit with
information relating to the chemical cargo and other data
associated therewith, and the interrogator unit is also
operable to cause the transponder unit to recall the
information and other data relating to the chemical cargo, and
transmit the data to the interrogator unit.
In a still further preferred embodiment, the interrogator
unit is designed to interrogate a plurality of transponders on
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different containers, the containers being either moving or
stationary, to uniquely determine khe information content of
each of the memories of the plurality of transponders
associated with the plurality of containers, and storing the
information content in the interrogator memory.
In another preferred form, the electronic remote chemical
identification system as described above is one in which the
interrogating process consists of a series of queries and
responses between the interrogator and the plurality of
transponders.
In yet another preferred embodiment, the electronic
remote chemical identification system as described above is
one in which the series of queries are arranged to provide an
increasing level uniqueness for identifying the transponders
with similar information content but di~fering by single or
multiple attributes of the information.
A still further feature of another embodiment of the
present invention is where the electronic remote chemical
identification system as described above responds by the
transponders in response to the queries by the interrogator
are determined by the process of a comparison between the
stored information content of the transponder memories and the
queries received from the interrogator.
According to a further aspect of the present invention,
in the electronic remote chemical identification system as
described above, the interrogator may communicate with and
command responses only from a single one of the plurality of
transponders based upon the uniqueness of the information
content o~ the transponder memories.
A still further aspect of the present invention, in the
electronic remote chemical identification system as described
above, is where the interrogator is designed to command the
single transponder on a single container with which the
interrogator is in communication to transmit a homing signal,
thus allowing determination of the angular bearing of the
transponder and container relative to a reference direction.
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~RIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a side view depicting the programming of a trans-
ponder unit during loading of a rail tank car;
Figure 2 is a top plan view of a railroad derailment
accident site;
Figures 3A and 3B are front and side plan views of the
hand-held interrogator unit:
Figure 4A is a block diagram of the interrogator-coder circuit;
and
Figure 4~ is a block diagram of the master coder circuit.
1316~8~
DETAILED DESCRIPTION OF THE PREF'ERRED EM~ODIMENT
The principle purpose of the electronic remote chemical
identification system is the same as placarding on a hazardous
materials car, that is, to provide readily the name of the chemical
being transported to emergency response personnel at an accident
scene and, likewise, to provide the same information to supervisory
personnel during normal, non-accident situations in commerce and
trade. This system is, however, based on the principle of remote
identification, and can be made much less vulnerable to damage
and loss in an accident. It is based on the principle that a
suitably protected transponder can be provided on each tank car
or truck containing hazardous materials. This transponder can
be electronically programmed with information about the chemical
being carried in that particular tank car, tank truck or partitioned
tank, such as the ~epartment of Transportation chemical number,
the chemical name, shipper or manufacturer's name, and any other
information of importance. In the case of an accident, the infor-
mation in the transponder can be retrieved at a safe distance
from the accident location by an interrogator or inquirer. The
interrogator commands the transponder by radio signals to respond
with the information stored in its memory. The signals recelved
b~y the interrogator are interpreted and displayed on a small screen,
such as that of a pocket calculator. The display will show the
chemical name, DOT number, the shipper's name and any other informa-
tion that may be helpful to the emergency response personnel.
The interrogator can also be used during routine and normaltransportation of hazardous materials to query the tank car~ or
trucks for identification of their contents in transit for inventory~
or other purposes. In the case of a derailment or road truck
accident, police, fire or other emergency responders can use portable
interrogators from a safe distance from the accident for quick
and positive identification of a chemical.
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The electronic remote chemical identification system consists
of three principle components: 1) the transponder; 2~ the master
coder; and 3) the in~errogator or mas~er inquirer. The master
coder and the interrogator can be incorporated in the same unit.
The transponder is a small microprocessor device powered
by rechargeable solar batteries. The transponder is normally
inactive. It may be enclosed, except for a small radiating
antenna, in a protective box, permanently attached at a convenient
and protected location on the tank car or tank truck. The trans-
ponder will receive and transmit digitized radio signals on command
only ~rom a master coder or an interrogator.
The maste~ coder and interrogator are similar in size to
a pocket calculator, with an antenna, an alphanumeric keyboard,
and a display screen.
Each tank car carrying hazardous materials or any other
cargo whose identification is necessary is ~itted with a trans-
ponder. At the time the car is filled with a chemical, the
shipper will key in the name of the chemical, the shipper's
name. and other in~ormation on the master coder. In operations
where large numbers of tank cars are filled with the same chemical,
the key-in procedure may be replaced by including a read head
i`n the transponder, and utilizing a precoded magnetic card
inserted into the read head during the initial coding procedure.
Other key-in procedures may include ultrasonic device-based
coding of individual tank car transponders.
In case of an accident, the hand-held interrogator brought
to the scene by emergency response personnel will provide all
necessary chemical identification. A fireman or policeman can
obtain this information at a safe distance of up to 500 meters
from the accident by interrogating the individual tank car
transponders and decoding their transmitted information.
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Two methods are described for interrogator operation. The
flrst is to provide the interrogator with a highly directional
antenna and sighting means such that the inter~oga~or can be
aimed at a specific tank car, and will receive information from
that car only. The second method involves storage of the names
of all commonly transported chemicals in the memory o~ the interro-
gator. At the accident scene, emergency personnel will approach
to within 500 meters of the accident sight and switch on the device.
The interrogator then sends digital signals corresponding to each
of the chemical names stored, commanding simultaneous responses
from all transponders on the tank cars preprogrammed with the
names of the chemicals being carried. The transponders simply
reply YES or NO to the questions asked by the interrogator, and
the interrogator then compiles a list of the chemicals for which
it receives a YES signal. To pinpoint the cars containing particular
chemicals of interest, the specific chemical is keyed into the
interrogator, and the interrogator display will indicate an angular
bearing on a null meter between the interrogator direction and
the cars containing the chemical of interest. This same procedure
can be employed with an interrogator in a helicopter over the
accident scene.
Referring now to Figure 1, a railway tank car 1 is shown
at a loading site being filled with a hazardous material through
fill pipe 2~ At this time, a foreman 11 or other personnel utili~es
an interrogator-coder 3 to code transponder unit 4 with the proper
identifying codes for the particular chemical to be transported.
As mentioned earlier, these codes can be entered individually
by the foreman through the use of alphanumeric keyboard 8, or
alternatively, as when a plurality of tank cars or trucks are
being filled with the same chemical, a pre-coded magnetic card
with the required information may be used. ~
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As mentioned pxeviously, the interrogator mode of operation
may be used simply for surveying or inventoring a rolling stock,
but the most lmportant usage occurs in the event of a highway
accident or railway car derailments as depicted in Figure 2.
A plurality of railway tan~ cars, lA through lD, are shown derailed
following an accident. They may be damaged or leaking, and emergency
response personnel arriving on the scene must first ascertain
the nature of the chemicals being carried before emergency operations
can proceed. These personnel, using a hand-held interrogator
unit 3, can interrogate the transponder units 2A through 2D on
all of the derailed tank cars, and immediately ascertain the cargoes
being carried so that proper emergency procedures may be performed.
Figures 3A and 3B show in detail the hand-held interrogator-
coder unit. It includes a handgrip 5 to facilitate its use, and
a gun sight 6A, 6B as an aid in aiming the unit at the desired
tank car transponder unit being interrogated. A whip antenna
7 is provided for receiving the returned signal from the transponder.
Other features include a keyboard 8 to allow coding of the trans-
ponder at the loading station, and also selection of specific
chemical names to be interrogated. Null meter 9 is utilized as
a directional aid in locating the cars containing specific chemicals
once the initial interrogation and chemical lists have been completed.
The initial interrogation involves queries of the transponders 2
from the list of all chemicals contained in the memory of the
interrogator-coder. YES and NO responses are noted with respect
to each of said chemicals, and then the interrogator 3 is programmed
to locate a specific chemical through the use of the null meter
9 and directional gun site 6.
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Once a specific tank car and its cargo are identified, a
liquid crystal display screen 10, capable ~f displaying several
linès o~ alphanumeric characters, allows direct display o~ the
information identifying the chemical cargo being carried in the
tank car, as well as any specific instructions regarding its
handling.
Figure 4A is a block diagram of the interrogator-coder circuit.
The heart of the system is the microprocessor 12. It controls
all the functions of the unit, and in conjunction with the timing
and interrupt control 13, performs proper synchronization of all
operations. The program memory and scratch pad memory 14 allows
the sequential performance of all necessary functions of the interro-
gator-coder. During initial coding operations, keyboard 8 is
utilized to program non-volatile random access memory 15 with
all necessary information reg`arding the chemicals to be transported,
DOT number, shipper's name and any other information regarding
the handling of the chemical. During the coding operation, the
UART circuit 16, under control of CPU 12, translates the coded
information for transfer by transmitter/receiver 17 and antenna
7 to tank car~mounted transponder 2. In the interrogator mode,
CPU 12 directs UART 16 and transmitter/receiver 17 to query any
t~ansponders 2 with respect to the chemicals stored in memory15.
Responses are received and processed under control of CPU 12,
and the results displayed on display screen 10.
A separate block diagram for the master coder is shown in
Figure 4~. While the functions of master coder and interrogator
may be physically separated, and provided by different hand-held
units, it is deemed desirable and more practical to combine their
functions in a single apparatus as illustrated in the drawings.
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The transponder unit is similar in construction to that of
the master interrogator-coder, in that it also is controlled by
a small microprocessor operating in conjunction with a small on-
board memory and transmitter/receiver circuit. The entire unit
is battery-operated, and in order to conserve battery life, i~
is recharged by a small solar panel located atop the transponder.
It is also designed with a minimum amount of hardware in order
to further conserve battery life, with most of i~s intelligence
being generated by software. The transmitter/receiver circuit
is normally in the receive mode, unless specific transmitting
instructions are received from the interrogator. Also included
is a non-volatile auxiliary memory to retain the coded information
from the master coder even in the event of power loss or unit
failure.
In use, master interrogator-coder 3 is utilized at the time
of filling of a tank car 1 or the like to code transponder 4 with
all necessary information regarding the chemical being transported,
the shipper's name, and other information regarding the handling
of the chemical. If, during transport an accident or derailment
should occur, emergency response personnel arriving on the scene
may utilize the interrogator-coder to identify and locate any
chemicals which may have been involved in the accident. Once
the chemicals are identified, the unit can also provide emergency
response personnel with any pertinent information regarding the
handling of the chemicals during clean-up and restoration of the
crash site.
