Britain's maritime economy, united to the logistical capabilities of the state bureaucracy, facilitated the maintenance of a navy vital to the defence of the nation, its trade and colonies, and to mounting operations overseas. For the maintenance and expansion of the British navy derived from efforts in both the state dockyards and the merchant ship yards and from the purchase and hire of vessels from the private sector. Although better-known for the management of affairs at sea, the Admiralty developed an important role in planning for the supply of ships and resources. Meanwhile the Navy Board, which managed the dockyards, benefited from improvements in its methods of controlling the yards. There the number of docks was fundamental to the size of the naval force that could be maintained at sea, for they determined the number of ships that could be fitted, refitted and repaired for service. The size of the workforce and the efficiency of work incentive schemes were also important, as was the supply of materials in which shortages occasionally threatened crises. Yet foresight, purchasing initiatives and a responsive commercial sector managed to provide all the materials needed by the navy, even when it reached its greatest size during the Napoleonic War, and despite about half coming from sources outside Britain.