Method and apparatus for testing rails for structural defects

A method and apparatus for testing rails for structural defects, the rails being associated with a railroad track include providing and using a first rail traveling vehicle for movement along a segment of rails followed by a second rail traveling vehicle for disposition behind the first rail traveling vehicle along the rails for testing with the first rail traveling vehicle having a first digital computer and a first analog computer and the second rail traveling vehicle having a second computer for display of data associated with the rails. A first modem assembly is provided in the first vehicle with a second modem assembly being provided in the second vehicle in communication with the first modem whereby data may be exchanged between the rail traveling vehicles. During testing, the first rail traveling vehicle transmits complete digital and analog rail structural and defect location information data to the second computer for analysis and action by the operators of the second vehicle.

BACKGROUND OF THE INVENTION 
The present invention relates broadly to apparatus and methods for testing 
rails, especially rails laid along a roadbed to form a railroad track. 
More particularly, the present invention is directed to a method and 
apparatus for testing rails using two linearly disposed rail-traveling 
vehicles and radio-based voice and data communication for data transfer 
therebetween to include the transfer of rail defect data acquired by the 
lead vehicle to the trailing vehicle. 
Steel rails, such as those used for railroad tracks which extend in a 
linear, generally parallel relationship, can develop internal structural 
defects such as stress fractures and other metallic structural anomalies. 
Such defects, if left unattended, can cause failure, especially fatigue 
failure, due to the repetitious loading and unloading of the rails by 
passing trains. Such rail failures can result in disrupted schedules as 
well as train derailments. 
As a response, it is generally known to periodically test the rails using 
some form of test system. The common form of rail testing involves 
ultrasonic technology. Specialized rail traveling vehicles carry 
ultrasonic transducers which transmit sound into the rails and receive and 
analyze return echo signals. Certain disruptions in the signal may be 
interpreted as rail defects and certain types of defects will reflect a 
characteristic signal such that when the characteristic signal is 
received, the type of defect may be readily determined. Typically, the 
transducers are carried on wheels or carriages, which are mounted on rail 
traveling vehicles such that the wheels are maintained in rail contact. 
Further, the transducers typically propagate waves at 0.degree., 
37.degree. and 70.degree. into the rails. The rail traveling vehicles also 
carry computers which can receive signals from the transducers, process 
the signals and interpret signal anomalies as defects and can also locate 
the defect within the rail. General ultrasonic inspection theory may be 
reviewed with reference to Norris, U.S. Pat. No. 4,429,576; Pagano et al., 
U.S. Pat. No. 4,487,071; or Cowan, U.S. Pat. No. 3,415,110. All three 
patents are referenced for their general teachings regarding ultrasonic 
rail testing. 
Typically, a rail traveling vehicle will carry the transducer system 
including a computer for data analysis. The vehicle will also typically 
carry an encoder which includes another rail contact wheel having a signal 
generating device associated therewith for periodic signals which are 
related to distance traveled from a predetermined starting point such that 
the location of the test vehicle may be determined by its displacement 
from a reference position. 
Federal Railroad Administration (FRA) rules provide that if the test 
vehicle identifies a suspicious location on the track, then the vehicle 
must stop and personnel must confirm the presence or absence of a defect 
at that location. Utilizing a single vehicle, the test vehicle would be 
continually moving down the track, stopping, then reversing to investigate 
indications identified by the test equipment. The speed at which this can 
be accomplished limits the amount of track that can be tested in a single 
day or other predetermined time period. In order to increase the amount of 
track tested per day, the chase car, or two vehicle system, has been 
developed. This system employs an additional vehicle, i.e., a second or 
chase vehicle that follows the test vehicle along the track. The chase 
vehicle is typically a smaller vehicle than the test vehicle with a 
minimum amount of equipment carried therein. The test vehicle is 
configured with a rail inspection system and the chase vehicle is 
configured for receipt of communication from the test vehicle and is 
sufficiently equipped to allow personnel to conduct the necessary 
confirmation. 
Currently, data sent from the test vehicle to the chase vehicle is 
minimalistic and typically involves a form of code to indicate that a 
defect has been found and a printer which will receive data from the test 
vehicle indicating where the defect was found. Personnel on the chase car 
must then use their own test equipment to verify the defect. The problem 
with this approach is that many of the test vehicle capabilities are not 
fully realized because the data sent to the chase vehicle is minimal and 
tests performed by the test vehicle must be reperformed by personnel from 
the chase vehicle. 
SUMMARY OF THE INVENTION 
It is, accordingly, an object of the present invention to provide a method 
and apparatus for testing rails for structural defects which includes 
transferring data to the chase vehicle which allows personnel within the 
chase vehicle to confirm a defect identified by the test vehicle within 
reduced time and effort over the prior art. 
It is further an object of the present invention to provide such a method 
and apparatus which will allow rapid and complete confirmation of all data 
gathered by the test vehicle to provide a complete record of rail test 
data. 
To that end, a method for testing rails for structural defects, with the 
rails being associated with a railroad track, ground supported and 
extending in a generally parallel manner along a road bed includes the 
steps of providing a first rail traveling vehicle for movement along a 
segment of rails for testing, the first rail traveling vehicle being 
equipped with a rail testing apparatus for production of data indicative 
of rail conditions and a first computer system in data exchanging 
communication with the rail testing apparatus, the first computer system 
having a display arrangement for displaying digital data and analog data 
associated with rails tested by the rail testing apparatus and a control 
interface for computer control by an operator; providing a second rail 
traveling vehicle for disposition behind the first rail traveling vehicle 
along the segment of rails for testing, the second rail traveling vehicle 
having a second computer disposed therein for display of data associated 
with rails tested by the rail testing apparatus; providing a first modem 
assembly operatively associated with the first computer and a second modem 
assembly operatively associated with the second computer with the first 
modem assembly being in data exchanging communication with the second 
modem assembly for data exchange between the first computer and the second 
computer. 
The method further includes the steps of moving the first rail traveling 
vehicle and second rail traveling vehicle along rails to be tested with 
the first rail traveling vehicle moving in advance of the second rail 
traveling vehicle; testing predetermined rail segments using the rail 
testing apparatus with the rail testing apparatus communicating rail test 
data associated with the structural condition of a tested rail segment to 
the first computer; displaying the rail test data on a computer screen 
wherein the rail test data may include data indicative of a structural 
defect in the predetermined rail segment at a defect location along the 
rail. The method further includes the steps of assessing the rail test 
data to determine if the rail test data is indicative of a possible 
structural defect in the predetermined rail segment at a defect location; 
selecting, upon determination of a possible structural defect, data 
indicative of the possible structural defect at the defect location, 
thereby creating a data snapshot of structural conditions along the 
segment of rails having the possible defect therein; communicating the 
data indicative of the possible structural defect at the defect location 
from the first computer system to the second computer using the first 
modem assembly and the second modem assembly; displaying the data 
indicative of the possible structural defect at the defect location using 
the second computer and assessing the data indicative of the possible 
structural defect at the defect location to locate the defect location and 
the possible structural defect in order to carry out a manual defect 
confirmation test and, if necessary, to initiate repair procedures. 
Preferably, the step of providing a first computer system includes 
providing a first digital computer and further includes providing a first 
analog computer in data exchanging communication with the first digital 
computer, with the first digital computer being for processing digital 
rail test data and the first analog computer being for processing analog 
rail test data. It is further preferred that the step of providing a first 
computer system includes providing a first display arrangement associated 
with the first digital computer for displaying digital rail test data and 
a second display arrangement associated with the first analog computer for 
displaying analog rail test data and the step of assessing the rail test 
data includes viewing and assessing digital rail test data in conjunction 
with corresponding analog rail test data to determine if the rail test 
data is indicative of a possible structural defect in the predetermined 
rail segment at a defect location. 
Preferably, the step of communicating data indicative of the possible 
structural defect to the second computer includes communicating digital 
rail test data and possible defect location data to the second computer. 
It is further preferred that the step of communicating data indicative of 
the possible structural defect to the second computer includes 
communicating the analog rail test data to the second computer. 
It is preferred that the step of selecting data indicative of a possible 
structural defect, thereby creating a digital snapshot of structural 
conditions, include the first digital computer communicating with the 
first analog computer to capture analog data selected, the analog data 
selected being indicative of a defect and a location of the defect. 
Preferably, the step of providing the first computer system includes 
providing a light pen used to select data by touching the light pen to a 
display and the step of selecting data indicative of a possible structural 
defect, thereby creating a data snapshot of structural conditions includes 
using the light pen to select data by touching the light pen to the 
digital display and a position on the display corresponding to a possible 
defect location. It is further preferred that the step of selecting data 
indicative of a possible structural defect, thereby creating a digital 
snapshot of structural conditions includes creating a snapshot of data 
corresponding to a rail segment having a linear dimension in the range of 
approximately 80-120 feet. Further, the step of selecting, upon detection 
of a possible structural defect, data indicative of the possible 
structural defect at the defect location includes the step of selecting a 
defect classification from a list of predetermined defect classifications 
stored in the first computer. Additionally, the step of selecting data 
indicative of the possible structural defect at the defect location 
includes the step of confirming the selection of a defect prior to 
communicating the rail test data to the second computer and, if the 
confirmation step is omitted, test data conforming to a predetermined rail 
length is transmitted automatically. If the confirmation is retracted no 
data is transmitted. The method further, preferably, includes the step of 
applying paint to the rails in a predetermined manner based on particular 
combinations of test data. 
Preferably, the step of providing a first modem assembly operatively 
associated with the first computer and a second modem assembly operatively 
associated with the second computer with the first modem assembly being in 
data exchanging communication with the second modem assembly for data 
exchange between the first computer system and the second computer 
includes the step of providing a first radio transmitter and receiver 
operatively associated with the first computer system and a second radio 
transmitter and receiver operatively associated with the second computer 
for maintaining radio communication between the first computer and the 
second computer for wireless data exchange there between. Preferably, the 
step of providing radio transmitters and receivers includes providing an 
arrangement for determining when communication between the first computer 
and the second computer have been terminated operatively associated with 
the first computer and the second computer and upon discovery of such 
termination of communications, the method further includes the step of 
alerting operators to such termination and the step of resending all data 
that has not been acknowledged by the second computer. 
It is further preferred that the step of providing a second display 
includes providing the second display with information regarding a 
location of the first traveling rail vehicle along the rails and upon loss 
of location information, the method includes the step of determining that 
the communication has terminated. The method further, preferably, includes 
the step entering results associated with the manual rail test into the 
second computer and communicating the result data to the first computer. 
An apparatus for testing rails for structural defects, the rails being 
associated with the railroad track, ground supported and extending in a 
generally parallel manner along a road bed includes a first rail traveling 
vehicle for movement along a segment of rails for testing, the first rail 
traveling vehicle having a real testing apparatus for the production of 
data indicative of rail conditions mounted thereto; a first computer 
system mounted within the first rail traveling vehicle in data exchanging 
communication with the rail testing apparatus, the first computer having a 
display arrangement for displaying digital data and analog data associated 
with rails tested by the rail testing apparatus; and a control interface 
for computer control by an operator; a second rail traveling vehicle for 
disposition behind the first rail traveling vehicle along the segment of 
rails for testing; a second computer disposed in the second rail traveling 
vehicle for display of data associated with rails tested by the rail 
testing apparatus; a first modem assembly operatively associated with the 
first computer and mounted within the first rail traveling vehicle; a 
second modem assembly operatively associated with the second computer and 
disposed within the second rail traveling vehicle, the first modem 
assembly being in data exchanging communication with the second modem 
assembly for data exchange between the first computer and the second 
computer to communicate data indicative of a possible structural defect at 
a defect location to the second computer using the first modem assembly 
and the second modem assembly; and an arrangement for displaying data 
indicative of the possible structural defect at the defect location 
operatively associated with the second computer for assessment of the data 
indicative of the possible structural defect at the defect location to 
locate the defect location and the possible structural defect in order to 
carry out a manual defect confirmation test and, if necessary, to initiate 
repair procedures. 
The first computer system preferably includes a first digital computer and 
further preferably includes a first analog computer in data exchanging 
communication with the first digital computer with the first digital 
computer including an arrangement for processing digital rail test data 
and the first analog computer includes an arrangement for processing 
analog rail test data. The first computer system preferably includes a 
first display apparatus operatively associated with the first digital 
computer for displaying digital rail test data and a second display 
apparatus operatively associated with the first analog computer for 
displaying analog rail test data for assessment of the rail test data by 
action of an operator in viewing and assessing digital rail test data in 
conjunction with corresponding analog rail test data to determine if the 
rail test data is indicative of a possible structural defect in the 
predetermined rail segment at a defect location. The first computer system 
preferably includes an arrangement for communicating the data indicative 
of the possible structural defect including analog rail test data to the 
second computer. Preferably, the first digital computer includes an 
arrangement for communicating with the first analog computer to capture 
analog data selected by an operator, the analog data being indicative of a 
defect and a location of the defect. 
Preferably, the control interface includes a light pen for use by an 
operator to select data by touching the light pen to a position on the 
display corresponding to a possible defect location with the data being 
indicative of a possible structural defect to thereby create a digital 
snapshot of structural conditions. Preferably, the apparatus for testing 
rails includes an arrangement for applying paint to the rails in a 
predetermined manner based on particular combinations of test data. 
Additional paint may be laid down every 0.1 miles for aiding and 
determining the location on the track. 
The apparatus further preferably includes a first radio transmitter and 
receiver operatively associated with the first modem assembly and a second 
radio transmitter and receiver operatively associated with the second 
modem assembly for maintaining radio communication between the first 
computer and the second computer for wireless data exchange there between. 
The apparatus further preferably includes an arrangement for determining 
when communication between the first rail traveling and the second rail 
traveling vehicle have been terminated and an arrangement for, upon 
discovery of such termination of communications, alerting operators to 
such termination, operatively associated with the transmitters and 
receivers. 
By the above, the present invention provides a method and apparatus for 
testing railroad track rails for structural defects which provides 
enhanced efficiency with respect to the use of time and equipment.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Turning now to the drawings, and more particularly to FIG. 1, an apparatus 
for testing rails for structural defects according to the preferred 
embodiment of the present invention is illustrated. FIG. 1 illustrates a 
first test vehicle 10 and a second, chase vehicle 22, in a very basic, 
outline form. As seen in FIG. 3, the test vehicle 10 is disposed on 
parallelly extending, ground supported rails 92 for testing while the 
chase vehicle 22 is disposed behind the test vehicle 10. The test vehicle 
10, disposed in advance of the test vehicle 10, includes a body 12 which 
houses a driver, operator and other equipment and personnel as will be 
seen in greater detail hereinafter. The chase vehicle 22 is supported for 
rail traveling movement by rail support wheels 16 which extend outwardly 
from wheel support members 18. The wheel support members 18 project 
outwardly from four comers of the test vehicle 10 to support the wheels 
16, and, consequently, the vehicle 10 for rail contacting movement. The 
rail traveling vehicle 10 also includes pneumatic tires 14, which can 
allow the first rail traveling vehicle 10 to move when not disposed on the 
rails 92. 
The second or chase vehicle 22 also includes a body 24 and rail contacting 
wheels 28 supported by support members 27 projecting outwardly from four 
corners of the vehicle body 24. The first and second rail traveling 
vehicles 10, 22 each include an antenna 50, 54 respectively for 
communication therebetween. It will be appreciated by those skilled in the 
art that the rail traveling vehicles 10, 22 depicted herein are depicted 
for illustrative purposes only and that the actual configuration of 
vehicles used may vary from that shown in the diagrams. 
Returning now to FIG. 1, the first rail traveling vehicle is illustrated 
generally at 10 with the body containment boundary illustrated at 12. The 
test vehicle 10 includes an ultrasonic rail testing apparatus 72 which 
will be explained in greater detail presently. The rail testing apparatus 
72 is operatively connected to roller search units 75 which carry a 
plurality of transducers 74. The roller search units 75 roll along in a 
rail contacting manner to periodically present the transducers to the 
rails so that the transducers may send and receive high amplitude, short 
pulsed, sound waves to and from the rails at predetermined angles of 
incidence and refraction. Rails with defects return signals earlier at the 
deflection location than those without defects. Typically, the waves are 
propagated at 0.degree., 37.degree. and 70.degree. into the rails. A 
distance measuring encoder 20 is also incorporated into the test vehicle 
10. The encoder sends periodic signals to determine the distance traveled 
by the test vehicle from a reference point. Signals are outputted from the 
transducer 74 and the encoder 20 and are fed to the ultrasonic test 
apparatus 72. 
Turning now to FIG. 2, the ultrasonic rail test apparatus 72 includes an 
ultrasonic signal processor 122 which includes gating and level detection 
as well as real time defect detection logic and real time computer 
integration circuitry and a monitor scope 120. The monitor scope 120 can 
provide instantaneous representations of the ultrasonic signals traveling 
within the rails 92. 
The encoder 20 sends its output to a milepost monitor 110 which includes a 
reference point determinator 112 and a driver milepost monitor circuit 114 
which sends an output signal to the monitor scope 120. An operator 
milepost monitor circuit 118 is in communication with the driver milepost 
monitor circuit 112 through a milepost monitor link 116. A defect/alarm 
monitoring system 128 is also included and the alarm/marking system 128 
includes an alarm/paint gun interface 130 which provides signal output to 
audiovisual alarms 132 and to a paint gun driver 134 which controls paint 
guns 77 as seen in FIGS. 2 and 3 which will apply paint to the track at a 
particular configuration for particular test data at a particular or 
predetermined location. The defect/alarm monitor is in two-way 
communication with the operator milepost monitor to provide distance, 
displacement or location calibration information to the marking system. 
The ultrasonic signal processor 122 is in two-way communication with an 
operator console 124 which includes a second monitor scope 120. The second 
monitor scope 120 is associated with the ultrasonic signal processing 
system 122 yet resides in the operator console 124. 
The operator console 124 also includes a digital computer 34 having a 
digital display 36 and an analog computer 42 having an analog display 44. 
Both are supplied with power from an uninterruptable power source 126. A 
light pen 38 is attached to the digital computer 34 to act as an operator 
controlled interface for selecting items on the display 36. While the 
previous discussion of items depicted in FIG. 2 includes items found in 
the test vehicle, FIG. 2 also illustrates items found in the chase vehicle 
22 as depicted therein. There, a second computer 56 including a second 
display 58 is provided along with a printer 59, a radio modem 52 and a 
cellular telephone 61 to provide data display and communications 
capabilities within the chase vehicle 22. It should also be noted that the 
electronics involved with the ultrasonic testing system have been used in 
the industry for several years and are well within the skill of one of 
ordinary skill in this art. Further, programming of the computers may be 
accomplished by one of ordinary skill in the computer programming art 
given the parameters defined by the present method. 
Returning now to FIG. 1, and to the equipment within the test vehicle 10, 
the digital computer 34 is in communication with a storage device 40 over 
communication lines 60. Further, the analog computer 42 is in 
communication with a data storage device 46 through communication line 62. 
The digital computer 34 and the analog computer 42 exchange data over data 
lines 64, 66. The analog computer 42 is in communication with the 
ultrasonic processing apparatus 72 through data line 78 while the digital 
computer 34 is in communication with the ultrasonic testing apparatus 72 
through data communication line 76. A radio frequency modem 48 including a 
data multiplexer and receiver/transmitter is provided within the test 
vehicle 10 in communication with the digital computer 34 through data 
communication line 68. An antenna 50 is provided for transmission and 
reception of electronic signals. The test vehicle 22 includes a similar 
radio frequency modem 52 including a data multiplexer and 
receiver/transmitter. The second radio modem 52 is in communication with 
the second computer 56 through data lines 80, 82 and is connected using a 
typical RS232 connection. An antenna 54 is provided and is operatively 
associated with the second radio modem 52 for transmission and reception 
of data signals. 
According to the method of the present invention and according to the 
preferred operation of the apparatus of the present invention, the test 
vehicle FIG. 3 is caused to move along the rails 92 in advance of the 
chase vehicle 22 as illustrated in FIG. 3. During movement along the rails 
92, ultrasonic testing is conducted using the rail testing apparatus 72 
with the transducer 74 emitting and receiving signals within the rails. 
The data is processed within the ultrasonic processor 122 and delivered to 
the digital and analog displays. As seen in FIG. 4, the digital display is 
illustrated generally at 84 and includes the location of an anomaly 86. 
Different signals are presented which are directed to the 0.degree. 
signal, the 37.degree. signal, the 70.degree. signal, an alarm signal, and 
a triple web signal. The data displayed is the data that has been 
processed using logic within the ultrasonic test processor 122. The 
position down the screen indicates the defect location and the vertical 
lines represent the different channels of ultrasonic information. 
With reference to FIG. 5, the analog information is displayed and 
illustrated generally at 88. Once again, the vertical distance represents 
the defect location along the track. An anomaly is illustrated in 90. The 
two displays are viewed by the operator and any combination of signals at 
a particular location that could possibly be a defect are selected. The 
selection is made using the light pen 38 which is touched to the screen. 
When this is done, the digital computer 34, which is linked to the analog 
computer 42, captures a "snapshot" of analog data centered on the location 
of the light pen selection. The length of the "snapshot" is one screen of 
data which equates to approximately 80-120 feet depending on the vehicle's 
speed and distance setting. The analog "snapshot" is stored on the digital 
computer with the digital data. 
When the selection is made on the digital screen 36, the operator is asked 
to pre-classify the suspect selection. This is done by selecting the 
appropriate defect classification with the light pen 38 on a menu bar (not 
shown) that appears at the bottom of the digital screen 36. A confirmation 
is then requested. If the confirmation is selected with the light pen 38, 
the data, including digital, analog and positional data, is transmitted to 
the chase vehicle 22. If the selection is not confirmed, the system will 
timeout and transmit the data to the chase vehicle 22. If the selection is 
retracted, no data is transmitted. Several rail lengths of digital data is 
transmitted. Then paint is applied to the rails 92 for certain 
predetermined combinations of data. Further, the test vehicle 10 applies a 
paint mark on the rail head every 0.1 mile down the track to aid the 
defect location effort when the chase vehicle 22 follows up. Both vehicles 
are equipped with encoders 20, 30 which are manually synchronized at the 
start of each day and at each milepost location on the track. The 0.1 mile 
paint mark acts as a backup. 
The radio modems 48, 52 have their own FCC licensed frequency and thus do 
not interfere with any other radio transmission. The transmission distance 
achieved is between 5 and 10 miles depending on the terrain. If, for 
whatever reason, the radio modems 48, 52 lose contact, both vehicles 10, 
22 are made aware of the situation by annotations on their respective 
display devices 36, 58. The test vehicle 10 operator can select a 
"re-send" button which instructs the radio modem 48 to resend all pending 
information. The system employs a handshaking protocol such that the 
pending information will include everything that the test vehicle 10 
system has not had an acknowledgment of as being successfully received by 
the chase vehicle 22. Chase vehicle 22 display 58 as illustrated in FIG. 6 
shows a continuously updated display of the test vehicle location. If this 
stops, the radio link has presumed to have been broken. The test vehicle 
10 is made aware of the number of packets of data to be sent to the chase 
vehicle 22. If this keeps increasing, then, once again, the radio link has 
likely been broken. If the radio link cannot be reestablished, the test 
vehicle 10 can revert to the standard "stop and confirm" test mode which 
eliminates the use of the chase vehicle 22. This does not require any 
action on the part of the operator and it can continue as long as 
necessary, i.e., until the radio link is reformed. 
The data sent to the chase vehicle 22 is displayed on the laptop computer 
56 acting as the second computer of the present invention. The data sent 
includes the digital and positional data and, if selected, the analog 
data. The laptop display is a list of the "suspects" or suspected rail 
defects sent to the chase vehicle as illustrated in 56. The suspects are 
listed at 94 in FIG. 6. Selection of one of the suspects will bring up the 
digital data associated with that suspect and, if it is available, the 
analog data can be viewed from there as well. The suspect list 94 also 
provides rail segment information, the status/result 98, the recording 
operator 100, the examining operator 102, and mileage location 104. Once 
the chase vehicle has located the spot on the track, the requisite 
confirmatory action is completed either by a ground examination or a hand 
test. The results of the ground examination or hand test are entered into 
the laptop computer 56 for that location. If the test vehicles had to stop 
in the "stop and confirm" mode, the complete details of the inspection are 
transmitted to the chase vehicle 22 such that the location is not 
inspected twice. If the operator on the chase vehicle 22 considers that he 
has insufficient data, he can request more digital data from the test 
vehicle 10 by using a single keystroke on the laptop or second computer 
56. This action does not affect the operation of the test vehicle 10. The 
results of all confirmatory actions on the chase vehicle 22 are 
transmitted to the test vehicle 10 such that both vehicles have a complete 
record of the inspection. 
By the above, the chase vehicle 22 personnel obtain complete data with 
regard to the rail conditions such that proper actions may be taken with 
regard to rail inspections. Further, complete records are compiled in both 
the test vehicle 10 and the chase vehicle 22 providing a redundancy-based 
data safeguard. The present invention will provide greater speed and 
flexibility associated with rail inspections. 
It will therefore be readily understood by those persons skilled in the art 
that the present invention is susceptible of a broad utility and 
application. Many embodiments and adaptations of the present invention 
other than those herein described, as well as many variations, 
modifications and equivalent arrangements, will be apparent from or 
reasonably suggested by the present invention and the foregoing 
description thereof, without departing from the substance or scope of the 
present invention. Accordingly, while the present invention has been 
described herein in detail in relation to its preferred embodiment, it is 
to be understood that this disclosure is only illustrative and exemplary 
of the present invention and is made merely for purposes of providing a 
full and enabling disclosure of the invention. The foregoing disclosure is 
not intended or to be construed to limit the present invention or 
otherwise to exclude any such other embodiments, adaptations, variations, 
modifications and equivalent arrangements, the present invention being 
limited only by the claims appended hereto and the equivalents thereof.