|
by Harry Hutchinson, Executive Editor
|
When
the Federal Railroad Administration announced earlier this year that rail
accidents had declined for the second year in a row, the agency attributed
the gains not to luck, but to steps that it has taken to improve the reliability
of equipment and of the people who operate it.
Under a program that it calls the National Rail Safety Action Plan, the
agency is addressing numerous factors that can contribute to accidents.
Some of its solutions are procedural, addressing human behavior and the
effects of fatigue. Others involve evolving technology meant to assure
that the road itself is safe.
 |
| A new track-inspection vehicle
operated by the U.S. Federal Railroad Administration, called the T-19,
carries laser equipment that monitors rails. |
Two of the largest causes of all rail accidents are not completely under
the control of railroads. They are collisions at grade crossings and with
trespassers on tracks. In the first case, the railroad can control the
quality of its signals that warn traffic that a train is coming, but the
most common cause of an accident at a crossing is that someone thought
he could beat the train. And the railroad has no control over a driver's
poor judgment.
In the case of trespass, incidents may arise from a commuter's decision
to take a shortcut to the neighborhood station or a feeling of adventure
among kids on a midnight stroll. Or just about any other situation in
which someone ignores the repeated warnings about how dangerous it is
to walk along the railroad tracks. Barring the invention of an impenetrable
shield to seal off the railway, the only control the railroads have over
trespass is to keep repeating those warnings.
Even so, the overall rate of accidents has been declining over the past
few years. There were nearly 19 accidents for every million train miles
in 2004. Last year, that rate had fallen to about 16 percentto 15.98,
to be exact.
The statistics include accidents that cover a range of severity. To an
outsider, the phrase "train accident" implies destroyed vehicles,
and a high probability of crippling injury or death. But spokesmen for
the FRA point out that it is not always so.
Accidents are reportable at certain thresholds. For instance, a train
accident is any in which there is more than $8,200 damage to track or
equipment. On the other hand, any impact with highway equipment, even
if damage is minor, must be reported, and so must any kind of accident
that results in an injury requiring more than first aid. According to
an FRA spokesman, if a single wheel were to derail under a train carrying
hazardous materials, the incident must be reported.
When the FRA talks specifically about "train accidents," the
term describes incidents that involve only railroad equipment and personnel,
in the yards and elsewhere. According to the FRA, the most frequent causes
of train accidents are human factors and track problems. Together they
account for more than two-thirds of all train accidents. Everything elseincluding
signal and all other kinds of equipment problemsaccount for less
than a third of train accidents. Railroads and regulators have a great
measure of control over these events.
The rate for train accidentsthose involving only railroad equipment
and employeeswas 4.38 per million train miles in 2004, the highest
in the past 10 years. The rate fell to 4.10 in 2005 and to 3.54 in 2006.
High-Tech Eyes on the Road
The FRA has various technologies to monitor the tracks. In the old days
it was the job of the track walker. It was probably great work, at least
in mild weather, to stroll through the countryside and take note of signs
of wear or weakness in the rails and the supporting roadbed.
Today, the plan is to get the job done better and faster by using accelerometers,
lasers, high-resolution cameras, or computer-controlled machinery. And
when any of these technologies identifies a questionable piece of track,
the global positioning system makes it possible to record the exact location
of potential trouble.
There are different classes of track, rated for different speeds. As the
speed limit rises, the gauge tolerance gets tighter. The FRA operates
several railcars that travel the nation's tracks to monitor gauge and
strength of rails in an initiative formally known as the Automated Track
Inspection Program.
Two older models use an instrumented drive axle to check the gauge of
track and also to apply a lateral load simulating a heavy train. A newer
model, known as the T-18, has a deployable fifth axle that allows it to
test track at a faster rate.
The cars also carry sensors that monitor ride quality to identify suspect
stretches of track.
Jo Strang, associate administrator for safety at the FRA, said the technology
was developed by the agency in cooperation with Ensco Inc. Two more track-testing
cars from Ensco are being added to the FRA's fleet. Strang said three
are assigned to the agency's office of safety and two to the office of
R&D.
Kevin Kesler, vice president of Ensco's rail division, said the T-18's
deployable fifth axle represents the second generation of the company's
Gauge Restraint Measuring System. It can test track at speeds up to 50
miles per hour while it applies a 14,000-pound lateral load. The older
technology, using one of the load axles for testing, has a top speed of
about 30 mph, he said.
When the gauge measurement system identifies a possible defect, the site
is marked by GPS and that information is sent to a database by wireless
transmission.
 |
| The deployable fifth axle on the
T-18 track-inspection car can test the gauge and strength of rails
at a rate of 50 mph as it applies a 14,000-pound load. The system
was developed by Ensco Inc. |
The two newer track testing vehicles, T-19 and T-20, differ from the
T-18. They carry a laser system that measures gauge and detects the outline
of a cross-section of rail. By comparing the image to an ideal, the system
can detect defects that may develop from wear and other surface damage.
Another track inspection technology uses a high-speed line scan camera
and is compact enough to be mounted on a hi-rail maintenance vehicle.
The camera specifically checks joint bars, the plates that link lengths
of rail.
According to Strang, a 5 mm crack can degrade a joint bar as much as 80
percent. A few years ago, in January 2001, there was a serious rail accident
in North Dakota that was caused by a faulty joint bar that caused a track
to fail, she said.
The National Transportation Safety Board and Congress directed the railroad
industry to improve inspection of joints after several serious derailments.
The hi-rail maintenance vehicle is a light truck that has a set of steel
wheels in addition to its tires, so that it can run on the highway or
on the train tracks. While the vehicle travels at speeds up to 55 mph,
the camera takes a picture every half millimeter along each joint bar.
It is looking for hairline cracks that usually start at the top of the
joint bar.
According to Kesler, the camera's resolution permits the discovery of
cracks less than a tenth of an inch long. He added that Ensco is doing
research to modify the system so that it can one day confirm the presence
and tightness of bolts and inspect other features of bars.
Other track-monitoring technology does not need maintenance vehicles,
and uses locomotives instead. Arrays of accelerometers mounted on locomotives
detect unusual accelerations from track and report anomalies, which are
pinpointed by GPS satellites.
So far, the system has been placed on about 100 locomotives, Kesler said,
and many railroad companies have expressed interest. He's sufficiently
optimistic about the system to predict that it "will probably be
on every locomotive in the next five to ten years."
The track technology promises to let the railroads perform predictive
rather than reactive maintenance on their roads. That can save money,
and improve both safety and reliability.
"Where we're going," Kesler said, "is that all of your
track will talk to you all the time."
Getting Humans to Err Less
Human factors account for almost 40 percent of accidents involving only
rail equipment and personnel. The driver of a train passes a stop signal.
Someone fails to return a switch to its proper position. Someone forgets
to set a hand brake. These are all examples of universal human frailty,
and they all have the potential to result in human disaster.
What's more, the FRA has identified a strong likelihood of fatigue playing
a role in one out of every four of those incidents.
Researchers looked at the work histories of crews for the 30 days leading
up to each of about 1,400 train accidents. The researchers found that
employees' estimated level of alertness correlated strongly with their
chances of being involved in an accident caused by human factors.
 |
 |
 |
| The FRA says its National Rail
Safety Action Plan, begun in 2005, is working. After a three-year
plateau, the total number of accidents declined slilghtly, about 2.4
percent, in 2005 and dropped by 8.5 percent in 2006. |
A bill before Congress, H.R. 1516, the Federal Railroad Safety Accountability
and Improvement Act, which is intended to reauthorize the federal rail
safety program through 2011, contains provisions that may make it possible
for the FRA to set hours-of-service regulations for railroad personnel.
Current hours of service, although they are enforced by the FRA, were
mandated by federal law.
In a paper released last November under the considerable title of "The
Railroad Fatigue Risk Management Program at the Federal Railroad Administration:
Past, Present and Future," the FRA discussed the hours-of-service
rules and other research into fatigue.
The current rules, mandated by law in 1907 and last updated 30 years ago,
say that a train service employee can work a single stretch of no more
than 12 hours. After that, the employee must have at least 10 hours off
duty. An employee working less than a 12-hour shift must get at least
8 consecutive hours off duty every 24 hours. That means an individual
can put in 11 hours and 59 minutes, be off duty for 8 hours, and be called
back to work.
Pushed to the limit, the rules don't assure a lot of time for sleep. According
to the FRA, a locomotive engineer could operate a train for as many as
432 hours in a single month, or the equivalent of more than 14 hours a
day, and still be operating within current federal rules.
The FRA argues that the rules are not based on scientific observation,
and in an attempt to correct that, the agency is developing statistical
models based on work histories that will predict when fatigue may be nearing
a critical point. The FRA has said this work is at least partly inspired
by similar research by the Department of Defense to predict the fatigue
and alertness levels of troops.
Models are turning up new points to consider. According to the report,
it seems that not only the length of the day, but also the time of day
counts. The FRA said research has shown that the circadian rhythm, the
internal clock that sets the rhythm of the day for most animals, including
people, may play a part in human factors accidents. According to the agency,
the risk of human factors accidents rises as much 20 percent among crews
working between midnight and 3 a.m.
Close, But No Report
Accident statistics for U.S. rail operations don't include the close callsaccidents
that almost happened, but were avoided at the last minute by the quick
reactions of an individual or, sometimes, by the intervention of blind
luck. They leave no record, so there's no telling just how serious a situation
was, or how it may be avoided in the future.
To get a fuller idea of the operational safety of American railroads,
the FRA wants to hear about the accidents that almost happened, but didn't.
Earlier this year, the agency started a program that is expected to bring
new data on close calls, in order to give a broader picture of safety
conditions that need to be addressed.
Under the FRA's program, called the Confidential Close Call Reporting
Pilot Project, Union Pacific Railroad, the Brotherhood of Locomotive Engineers
and Trainmen, and the United Transportation Union have agreed to let railroad
employees report possibly dangerous situations and near accidents to the
Bureau of Transportation Statistics.
Strang pointed out that the program makes it possible for reports to be
placed anonymously.
 |
| An optical inspection system using
a high-speed line scan camera looks for tiny cracks in the bars that
join rails. The equipment is compact enough to be mounted on a hi-rail
maintenance vehicle. |
According to the FRA, incidents can range from careless lifting on the
job that puts an employee at risk of minor injury to more serious behavior,
such as a train operating in non-signaled territory proceeding beyond
its track authority, or a crew member's failure to properly test an air
brake.
The pilot project started at Union Pacific's railroad yard in North Platte,
Neb., in February and is being extended to other yards, including BNSF
Railway in Lincoln, Neb., and Canadian Pacific in Portage, Wis.
Right now, the plan calls for reports to be collected for the next five
years to build enough information for thorough analysis. The FRA said
a review team will evaluate reports as they come in, so that officials
can make safety recommendations for situations that require immediate
attention. The FRA said it is talking with some commuter railroads about
the possibility of adding another project location.
It seems the National Rail Safety Action Plan is yielding significant
results. According to the FRA, the number of derailments in 2006 declined
8.3 percent and collisions between trains decreased by 27.1 percent from
2005.
According to a statement by the U.S. Department of Transportation Secretary,
Mary E. Peters, human error was still the leading cause of all train accidents,
but human factors accidents declined 20.2 percent in 2006. Train accidents
caused by track issues decreased 5.8 percent, and those caused by equipment
failure fell by 8.2 percent. Accidents linked to signal problems declined
27 percent.
Of course, a safety action plan or any other program won't be able to
eliminate all accidents, not even those whose causes are under the control
of railroad operatorsnot as long as trains remain heavy, can't stop
on a dime, and run under the supervision of mere mortals. Application
of improved practices and technologies can, however, bring us ever closer
to the impossible goal of zero accidents.
The numbers say that, for the past two years, the safety action plan has
done exactly that.
home
| features | breaking
news | marketplace
| departments | about
ME back issues | ASME
| site search
© 2007 by The American Society
of Mechanical Engineers
|