Tail Swing 1 : Clearance distance from center of rotation to maximum rear extension of revolving upperstructure. Also called Rear End Radius. (Spec 2C)
The Mudblogger (Oilfield, Energy and Related Photographs), Oil Field Glossary, TX, USA 2014. http://mudblogger.com/oilfield-glossary/, (Oil - Amer) {777}