The "Watchtower" force, numbering 75 warships and transports (of vessels from the U.S. and Australia), assembled near Fiji on 26 July and engaged in one rehearsal landing prior to leaving for Guadalcanal on 31 July. The commander of the Allied expeditionary force was U.S. Vice Admiral Frank Fletcher, Commander Task Force 61 (whose flag was on the aircraft carrier ). Commanding the amphibious forces was U.S. Rear Admiral Richmond K. Turner. Vandegrift led the 16,000 Allied (primarily U.S. Marine) infantry earmarked for the landings. The troops sent to Guadalcanal were fresh from military training and armed with bolt-action M1903 Springfield rifles and a meager 10-day supply of ammunition. Because of the need to get them into battle quickly, the operation planners had reduced their supplies from 90 days to only 60. The men of the 1st Marine Division began referring to the coming battle as "Operation Shoestring".