This is the percentage of Locomotive Available time that the diesel engine is turned on. Conversely, Engine Shutdown is the percentage of Locomotive Available time that the diesel engine is turned off
Transport Canada, 'Changing Transportation Behaviours', 'Rail Freight Service', 'Rail Safety and Emergency Glossary', 'Railway Operations Glossary', 'Road Traffic & Transportation Safety and Emergency Glossary', 'Safety Glossary', 'Transportation of Dangerous Goods Glossary, Ontario, Canada 2013. http://www.tc.gc.ca/eng/menu.htm, (Changing Transp Behaviours, Rail Freight Srvc, Rail Sfty and Emr, Railway Oper, Road Trfc and Transp Sfty and Emr, Transp of Dangerous Goods - Canad) {643}