The main technical problem was ensuring a constant distance between the two ships throughout the process. Schematic for a Temperley transporter, a crane for hauling heavy loads, and used in early UR trials in 1898. Over 20 submissions were made to the RN between 18 alone. Īlthough his concept was rejected by the Admiralty, the advantages of such a system were made apparent to strategists on both sides of the Atlantic. His proposal was for transfer to be effected through watertight coal carriers suspended from a cable between the two ships. He argued that a successful system would provide a minimum rate of 20 tons per hour while the ships maintain a speed of five knots. Lieutenant Robert Lowry was the first to suggest the use of large-scale underway replenishment techniques in an 1883 paper to the Royal United Services Institute. The speed was too slow to be practicable, and calm weather was required to keep the neighbouring ships together.
Įarly attempts at refueling and restocking at sea had been made as early as 1870, when HMS Captain of the Channel Squadron was resupplied with coal at a rate of five tons per hour. This had two disadvantages: the infrastructure was vulnerable to disruption or attack, and its use introduced a predictable pattern to naval operations that an enemy could exploit. This capability allowed the Navy to project naval power around the world and far from home ports. The Royal Navy had an unparalleled global logistics network of coaling stations and the world's largest collier fleet. Prior to underway replenishment, coaling stations were the only way to refuel ships far from home.
Early ship resupplying at sea, such as an attempt with HMS Captain in 1870, was slow and often hazardous.