Underway Replenishment
Since its origins, the viability of the carrier battle group has been dependent on its ability to remain at sea for extended periods. Specialized ships were developed to provide underway replenishment of fuel (for the carrier and its aircraft), ordnance, and other supplies necessary to sustain operations. Carrier battle groups devote a great deal of planning to efficiently conduct underway replenishment to minimize the time spent conducting replenishment. The carrier can also provide replenishment on a limited basis to its escorts, but typically a replenishment ship such as a fast combat support ship (AOE) or replenishment oiler (AOR) pulls alongside a carrier and conducts simultaneous operations with the carrier on its port side and one of the escorts on its starboard side. The advent of the helicopter provides the ability to speed replenishment by lifting supplies at the same time that fuelling hoses and lines are delivering other goods.
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