Prior to the beach landings themselves, a total of 24,000 paratroops were dropped in the vicinities of Sword and Omaha beaches. Their objective was to secure key sites which would support the troops coming ashore. Each main Allied army was assigned specific beaches. The British landed at Sword and Gold, the Canadians at Juno and the Americans at Omaha and Utah. The entire force was split between the 1st Army, comprised of American troops and directed by General Bradley, and the 2nd Army comprised mainly of British and Canadian troops and directed by General Dempsey. The combined total across all beaches and airborne drops on D-Day was 156,000 troops, with many times more arriving over the following weeks after the beachheads were secured and the floating Mulberry harbours constructed. An array of vehicles, from warships to amphibious landing craft and many different types of tank, were instrumental in the overall success of the operation.