The Cardinals hope that by operating the detectors at only one gate right now, fans will not need to allow much extra time to enter the stadium.
"From the fan standpoint, we'll certainly ask for their patience as we go through that," said Joe Abernathy, vice president of stadium operations. "It shouldn't be as drastic as going to the airport. We just want to let everybody know that this is an ongoing unfortunate trend that is out there in sports facilities. For us to provide that level of safety that we would like to provide everybody, we have to do that."
Unlike at the airport, fans will not need to remove belts, shoes, jewelry, jackets, coins or wallets. Cell phones, cameras, sunglasses cases, keys and other large metal objects will need to be taken out of pockets.
The Cardinals have chosen to use metal detectors instead of hand-held detectors because they feel it will expedite the process.
"We figure with the number of events that we have and here with the Cardinals, the number of people we put through here at 40,000 a night, then we would worry about backing up the gates," Abernathy said. "We feel the best way to do that in our situation is through walk-through metal detectors."
The Cardinals will evaluate how smoothly the process goes at Gate 4 for several games before determining whether additional metal detectors will be in place before the end of this season. For those who cannot or choose not to proceed through the metal detectors, wands will be used.
Jenifer Langosch is a reporter for MLB.com. Read her blog, By Gosh, It's Langosch, and follow her on Twitter @LangoschMLB. This story was not subject to the approval of Major League Baseball or its clubs.