RPM is the acronym used for revolutions per minute. It measures the number of revolutions completed in one minute around a fixed axis, giving the speed of a mechanical component. It is commonly used to describe the performance of automobile engines.
Like most ballparks built from the 1990s onward, Safeco Field is a 'retro-modern' style ballpark that incorporates many of the features of ballparks built in the 1950s and earlier with modern amenities.
Safeco Field History. The Mariners' state-of-the-art ballpark officially opened for business on July 15, 1999 after more than five years of planning and construction. Since then, it has become one of the premier facilities in Major League Baseball.