The Minneapolis Water Works uses two Roots blowers that were installed and in continuous operation since 1941. The blowers are used to unload rail cars of limestone that Minneapolis uses to soften its drinking water. The blowers are located on the top floor of a three-story facility, which also houses an auger conveying system and a bag house. Even though the bag house is well-maintained, the blowers are subjected to a good amount of dust, which creates an abrasive environment. Ken Johnson, the company's maintenance shop foreman, says the only maintenance required during the last six and a half decades has been the replacement of seven sets of belts and one motor. "The lubrication is monitored, and no other maintenance has been needed," he added. More information is available from Dresser Roots, Houston, TX, at 877-363-7668 or www.rootsblower.com.