double carry
n.— «“In effect, what we had to do was make every bit of forward progress two times over, going back each time to collect the remainder of our supplies and bringing it back to where we had stopped for the day,” explains Reims. The technique—known as “double carry”—is a familiar one for expeditions; at least the daily tasks remain humanly possible, and also the risks of damage to supplies and sledges are kept to a minimum. But progress is slow.» —“North Pole conquerors return home” by Jouni Kantola Helsingin Sanomat (Helsinki, Finland) May 6, 2006. (source: Double-Tongued Dictionary)