The British HACS and FKS anti-aircraft fire control systems were less than satisfactory in service during World War II. While Delhi was in refit the British asked that the U.S. Navy's MK 37 Gun Fire Control System be installed as a test bed along with the 5-inch/38 calibre guns. The results were most impressive to the service and a request was issued for 42 of the systems to be sent to the Royal Navy for installation on their ships.
During World War II, British HACS and FKS anti-aircraft fire control systems were inadequate in service. While Delhi was being refitted, the British requested that the U.S. Navy's MK 37 Gun Fire Control System be installed alongside the 5-inch/38 calibre guns as a test bed. The results were impressive to the service, and a request was issued for 42 of these systems to be sent to the Royal Navy for installation on their ships.