By DOUG WILSON

Herald-Whig Senior Writer

One of Ameren Illinois Utilities' best tools for dealing with major power outages is a tractor-trailer unit that is known as a storm trailer.

Customers might never want to see a storm trailer in their neighborhood, because it means something bad has happened. But if there's a storm or other problem, the trailer is a welcome sight.

"We've got six of these trailers in Illinois and four in Missouri" said Bill Prebil, vice president of regional operations at Ameren.

The utility has used the units since 1996 and sees them as the best way to deal with major outages. Each trailer costs about $50,000 to buy and modify and it carries $75,000 worth of emergency equipment and repair supplies.

Steve Bradshaw, who manages AmerenCIPS Division 2 out of Quincy, said an ice storm near Jacksonville during the winter showed the value of an emergency response program. AmerenCIPS activated its own linemen, called in others from within the corporation and activated a mutual response network that brought in hundreds more workers.

"We had about 330 linemen" working to restore power to 17,000 customers, Bradshaw said.

The storm trailers are invaluable in these cases because each unit can serve an average of 250 repair crews. Shelves, racks and cabinets in the trailer have replacement electric line, splices and other equipment. The trailers do not carry new utility lines because those are available in the district headquarters in different parts of the state.

Another high-tech tool the utility uses is known as the OAS -- for Outage Analysis System. This computer-controlled system recognizes when customers call in to say their power has gone out. As more customers call in, the computer can generally determine whether outages start at the substation, the transmission lines, a transformer or from a single line connecting customers to the power grid.

"We want people to call in when they've got an outage," Bradshaw said.

Prebil said by 2010, Ameren Illinois Utilities plans to spend $900 million for capital upgrades throughout the state. In the Quincy area alone the company plans improvements worth $12.2 million this year.

Some improvements that protect the flow of electricity include predator fences to keep animals out of substations. Tree trimming is another important element because trees cause a majority of the utility's power outages.

Ameren serves 1.2 million electric customers in Illinois and 840,000 natural gas customers.

-- dwilson@whig.com/221-3372