April 17, 2006
Everything was working
as it should. There was nothing wrong with the ride. Yet, if the
ride was functioning properly, then why did it end in tragedy?
"Thu Apr 13, 2006
9:10 PM BST ORLANDO, Florida (Reuters) - A 49-year-old German woman
died after riding a rocket simulator at Walt Disney World's Epcot
theme park in Florida, the second person to die in less than a year
after riding on Mission: SPACE, state officials said on Thursday.
State regulators said Disney had told them the woman, who died Wednesday
evening, may have had some prior health problems including high
blood pressure and chronic headaches. ... The attraction uses spinning
centrifugal force to create the sensation of a rocket launch. 'They
didn't see anything out of the ordinary ... Disney was satisfied
that it was behaving normally.' Mission: SPACE reopened to the public
on Thursday morning, Disney said in a statement. In June 2005, 4-year-old
Daudi Bamuwamye of Pennsylvania died after riding Mission: SPACE
with his mother and losing consciousness. An autopsy by a Florida
medical examiner's office determined that Bamuwamye had an undiagnosed
heart defect which put him at risk of sudden death under stress.
Mission: SPACE was inspected by Disney after Bamuwamye's ride, found
to have no mechanical problems and also reopened the following morning."
Two cases of illness --
at least one of which was undiagnosed -- that ended in death when
combined with a ride. How is it that a ride that is working as it
should would cause such problems for its riders?
"The thrill of a good
roller coaster: you hold your breath, your hair blows in the wind,
and your heart races as you speed along the track. A report in an
issue of Neurology (January 11, 2000) suggests that some giant roller
coasters can do even more...they may cause the brain to bleed and
the blood to clot in what is called a subdural hematoma. A subdural
hematoma is caused by the rupture of blood vessels near the surface
of the brain. Blood gets trapped between the meninges (coverings
of the brain) and the brain. The hematoma causes pressure on the
brain, which may cause headaches and vomiting."
With all the possible medical
"Many people wonder
whether coasters are safe. ... From a physics standpoint, coasters
are quite safe. For instance, in an inversion, the forces always
conspire to keep the rider in the car. Coaster designers calculate
the forces on the coaster to make it feel dangerous, but really
be quite safe. However, these calculations are done assuming the
rider does nothing unusual. If you stand up in a sit-down coaster,
the designer's calculations will no longer apply. Then, negative
G's may be enough to eject you. On a curve, your center of gravity
may end up above the side of the car, and you will be in serious
danger of being thrown out. If treated with respect, coasters are
quite safe. The chances are very slim that you will be hurt on a
coaster if you ride it correctly. If you do something foolish, though,
you greatly increase your chances of injury."
Rides are designed to offer
fun by pushing the limits in a controlled environment. With so many
variables, it is difficult to completely control any environment...
"Complex Rides + Complex
Humans = Complex Safety Issues
* Millions of patrons visit amusement parks and carnivals in the
United States each year. ...
* Injuries range from stubbed toes and bruised knees to death and
dismemberment. Because of the strong forces exerted by the
machinery, the extent of injury from an amusement ride accident
is often a matter of luck. If a rider
is tossed into a bush, for example, he might walk away without injury.
But if that same rider is ejected into a wall, the outcome will
be far more serious. The causes of ride-related injuries, and the
strategies for preventing them, are equally diverse. ...
Common Causes of Ride-Related Injury
* Youth and Inexperience
* Water Slides, Go-Karts, and Other Patron-Directed Rides
* Patron Daze, Wiggle Worms, and Horseplay
* Size Mismatch Between Patron and Ride
* Intensity of Motion and Emotion
* Equipment Failure
* Operational Issues
* Sales vs. Safety: Conflict Between Marketing Message and Reality
* Ride-Specific Risk Factors"
There are so many variables.
There are so many issues to take into consideration. Riders need
to know what the rules are for each ride; and they need to know
why those rules are there in order to know how those rules pertain
to their lives.
"Thursday, 10 January,
2002... CPSC figures show injuries on fixed-site amusement parks
increased by 95% between 1996 and 1999, while attendance only increased
by 6.5%. They estimated the risk of sustaining an injury which needed
hospital treatment was one in 15m rides, and the risk of being fatally
injured was one in 150m rides. During the past 10 years, there have
been 15 reports in medical literature of life-threatening brain
injuries caused by riding rollercoasters. Several of the authors
of these reports have said giant roller coasters produce enough
G-forces to cause brain injury. Potential head injuries include
subdural haematoma, a serious injury characterised by blood under
a membrane surrounding the brain. Rides could also cause other health
problems including seizures and back injuries. The researchers of
this latest study believe federal legislation passed in 1981, which
exempted large, fixed-site amusement parks from reporting injuries
or undergoing accident investigations by the CPSC, led to the actual
number of injuries per year to be underestimated."
Rides and riders are abundant.
Injuries are few (as a percentage of total ridership), and vary
greatly in severity. That said, there are still many variables to
consider. Machines can malfunction, but even when they are working
perfectly there can be tragedies. Ride operators can make mistakes
or fail to complete all safety check. Riders sometimes choose not
to follow the rules, and sometimes don't know the limitations of
their own bodies.
"Human error is always
a concern when devising machinery to be used by humans. Accepted
theory suggests that systems be designed to provide error prevention,
error capturing, and error tolerance. Woodcock and Tsao found that
each of these is present in amusement rides, and each may also fail:
* Ride designers and owner/operators furnish certain error prevention
mechanisms (restraints, warnings signs to deter certain behaviors
and promote safe behaviors)
* Safety margins in ride design, installation, and operation help
ensure a high degree of error tolerance .
* Ride operators perform error capturing functions such as enforcing
height limits, guiding guests during load/unload, checking restraints,
monitoring for unusual conditions, and performing an emergency stop
if necessary. Woodcock and Tsao make the point that 'operator's
vigilance is not a perfect "antidote" for rider error
... In addition, operators themselves may make errors.' "
Questions of the Week:
What do people need to take into consideration when deciding which
rides to enjoy? How is this different for different people? What
do you need to know about your own health when making that decision?
What are the responsibilities of the park and the employees to keep
the rides safe for those who ride? What responsibilities do the
riders have? What would you say to someone who is not concerned
because, "These accidents are rare; it could never happen to
me"? What would you say to someone who won't ride any rides
because, "They are too dangerous"?
Please email me with any ideas or suggestions.
Note: Due to increasing amounts of SPAM sent to this account, please include "QOW" in the subject line when sending me email.
I look forward to reading
what you have to say.
Health Community Coordinator
Access Excellence @ the National Health Museum