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. Safeco Field (sometimes referred to as just Safeco) is a retractable roof baseball stadium located in Seattle, Washington. However, unlike other retractable roof stadiums, Safeco Field has what is called a retractable umbrella. This is because when the roof is closed the stadium is still open on the sides to the outside weather so the Mariners can play outdoor baseball even in the rain.