Supplying a large fleet from colliers could require many vessels or a long pause during which the fleet was unavailable for operations. Whether the transfer was possible also depended on geography and weather, so no commander could assume it would work everywhere. Oil replenishment still required time and favorable conditions. Hoses and pumps nevertheless made the transfer faster and more feasible than physically moving coal, a difference with direct strategic value for a navy supporting a global empire.
Notable Point · 28:16-30:10
Weather and lost operating time limited coaling at sea
Coaling a fleet depended on sheltered water and lengthy distribution, whereas pumpable oil made underway replenishment substantially more practical.