“Under normal operation of single or coupled electric engines, rear pantograph shall be up on each engine except class E-44, which must have the leading pantograph up. Adjacent pantographs of coupled engines should not be up when it can be avoided.”
"Engineman must be on the alert for excessive arcing caused by sleet formation, and when such is observed he must at once comply with instructions governing double pantograph order operation. The first indication of sleet shall be reported promptly to the Superintendent who will issue a double pantograph order when conditions warrant.
"With double pantograph order in effect, electric engines operating singly shall run with both pantographs up…
“Electric engines coupled shall run with both pantographs up on leading engine and rear pantograph up on each trailing engine…”
“Patrol trains, consisting of five or more multiple-unit cars or two electric engines coupled, will be assigned to remove sleet from contact wires…”
“Two electric engines light, operating as a patrol train to remove sleet from contact wires, shall run with two pantographs up on leading engine, and with rear pantograph up on trailing engine…Any three pantographs may be up in an emergency but rear pantograph of the leading engine and the front pantograph of the trailing engine shall not be up at the same time when it can be avoided.”
From C. T. 290 Electrical Operating Instructions, The Pennsylvania Railroad, Revised December 15, 1966
“Each locomotive normally uses one pantograph at a time. Aerodynamic tests showed that the best arrangement is for both shuttle locomotives to operate with their rear pantographs raised. Main-line locomotives with two pantographs generally do this as well, but for a different reason; if the leading pantograph hits an obstruction, debris could be carried back to damage the rear pantograph, so putting both out of action.”
From Semmens and Machefert-Tassin,