Wind tests for rescue vehicles
Wind tests for rescue vehicles
By Eliot Kleinberg
Palm Beach Post Staff Writer
Monday, December 9, 2002
The woman on the other side of the phone was clutching her children. Above her, the roof was peeling off. Beside her, the walls were threatening to collapse. The 911 emergency dispatcher could do nothing for her. Hurricane Andrew was upon South Florida. Rescue could not come.
On Aug. 24, 1992, Dade County emergency managers began pulling rescue vehicles into stations and refusing emergency calls a little after 4 a.m., within an hour of Andrew's eye making landfall. They were invoking a long-held policy of shutting down when sustained winds anywhere in the county reach 40 mph, said Hernando Vergara, then the emergency management division's hurricane coordinator, now a county spokesman.
"I remember getting calls that literally made us cry," Vergara said. "We felt helpless."
The mantra is simple: If the hurricane is raging, you're on your own. Don't count on police, fire or ambulance vehicles to struggle in high winds to reach you.
With an $82,500 contribution from Palm Beach County, researchers are now trying to determine that critical wind speed at which it's no longer safe to send out rescue vehicles.
"You're talking about people who are more willing to take risks to help people, as we know all too well," said Thomas Schmidlin, a meteorologist and chair of the geography department at Kent State University in Ohio. "What level of risk are they willing to accept?"
Across the state, the range of points at which managers stop responding is 39 mph -- minimal tropical storm force winds -- to 45 mph. Palm Beach County Fire-Rescue starts limiting responses at 35 and raises the bar as wind speeds increase, up to about 65 mph, spokesman Sean Pamplona said. Martin and St. Lucie county officials set the point at 39 mph. Managers all said they will make judgment calls past those points on extreme emergencies.
The dilemma: If such triggers are unnecessarily conservative, lives may be at risk or even lost. Too high, and rescue workers are placed in too much danger.
"School buses are on the road in the Midwest and Plains in 50-mph winds all the time," Schmidlin said. He said rescue vehicles are heavier and more stable than cars or minivans. A disadvantage is that they are taller and so more surface is exposed to the wind, but drivers have had extensive training, Schmidlin said.
Emergency managers also have said your vehicle is safer from winds and flying missiles in a covered garage than in the open, and some of that research money will go toward determining just how safe.
The results of the two studies will be shared with emergency managers across Florida and nationwide.
Schmidlin's team already has done extensive research on the effects of wind on stationary cars and minivans and determined winds would have to be above 115 mph to tip over those studied. Of course, factors are completely different if a car is moving. It faces all sorts of dynamics, such as crosswinds and debris both on the road and in the air. Mostly, Schmidlin said, "It becomes a driver-dependent factor." It is how an individual driver handles those winds that most determines the vehicle's fate, he said.
While managers hope people will have stopped driving around long before a storm arrives, what gives them nightmares is the idea of far more people than necessary trying to leave the region, leading to a traffic jam.
But the Palm Beach County officials specifically wanted to know about the effects of wind on rescue and police vehicles.
"They would like to keep 'first responders' out on the roads doing the things they have to do. Those vehicles tend to stay out longer. They want to know at what wind speeds you pull those people off the highway," Schmidlin said.
In the case of Andrew, there was also the factor of making a blanket decision, said Miami-Dade Emergency Management Director Chuck Lanza.
"The south end of the county had 40-mph winds. The north end of the county had nothing," said Lanza, who, as then-acting communications chief for Metropolitan Dade County Fire Rescue, made the call the night of Andrew. "With a small storm like Andrew, we realize now that half the county could have worked half the night."
The wind tunnel tests will not use actual vehicles, Schmidlin said. Even the biggest wind tunnels could hold some cars, but there must be enough space between the vehicle and the wall to avoid a "bounce" effect that would skew results, he said. So Kent State contracts with Wichita State University in Kansas to build wooden 1/6-scale models. Schmidlin said the size and material aren't important, just the shape. He said Wichita State will build a model firetruck, ambulance, even a city bus, since buses probably will be used in evacuations.
The parking garage study is designed with the idea that they would be "refuges of last resorts:" People in increasing winds would flee cars and run to such places for safety.
The rescue vehicle study is needed because manufacturers can't give accurate data on how their vehicles will do in high winds, and cities and agencies often have to make an educated guess, said Helene Wetherington, assistant director for the Palm Beach County Emergency Operations Center.
"The 'first responders' will continue to respond as long as they can continue to do so safely," Wetherington said. "It's still a balancing act, but they want to know at least how safe it is for the vehicles."
Wetherington said Lee and Broward counties helped defray the cost of the grant and the county is hoping other counties will chip in.
Story from http://www.gopbi.com/