June 2024

Continuous operation of the humps should be the first consideration, and ordinarily should take preference over other conflicting movements. These conflicting movements which delay the humping of cars should, as far as possible, be anticipated and should be made at times when delay to the hump will be reduced.  

Potomac Yard Special Instructions for the Government of Employees of Potomac Yard, Instructions covering the Operation of Hump and Classification of Cars, In effect August 15, 1973.