A comparison of British and American anti-aircraft fire control systems in World War II.
This Committee's major conclusion in regards to destroyers was that high level bombers would only be passing the destroyers on their way to strike at capital ships and that they would not be attacking the destroyers directly. An analysis in this report showed that attacking aircraft flying at a height of 5,000 feet and at a distance of 5,000 yards (1,525 m and 4,570 m) would only be 18 degrees above the horizon. For that reason, the Committee concluded that 'future destroyers should not be fitted with a dual purpose armament' and recommended a maximum main gunnery elevation of only 40 degrees.
No analysis of HACS would be complete without a brief mention of the contemporary USA's Mark 37 Gunfire Control System (GFCS), some of which were also supplied to the Royal Navy. In British terms, these were "HA/LA" systems, that is, they were intended for use against both aircraft and surface targets. This system was first introduced into service on the destroyer USS Sims (DD-409) in early 1940 and was quickly adopted for all new US warship construction of destroyer size and larger. Some auxiliaries built pre-war were also equipped with this unit. The Mark 37 GFCS differed from previous US directors by having the analog computer and stable vertical mounted below decks in order to reduce the size and weight of the director itself. An important feature of this system was that AA time fuzes were automatically - and continuously - set in the shell hoists, which not only eliminated a source of human error, but also meant that the rate of fire was not affected by the skill and speed of a human fuze setter, thus allowing faster firing cycles. This feature allowed ships to fire whatever barrels were ready at any given time, again resulting in an appreciably faster rate of fire. This continuous fuze setting also meant that these ships could fire a 'rolling barrage' pattern that followed the aircraft target as it moved through the sky, unlike the 'once and done' barrage pattern.
Full comparison:
https://www.quora.com/Were-British-warships-as-effective-in-thwarting-Japanese-Kamikaze-attacks-as-American-warships-were/answer/Trent-Telenko
"These things must be done delicately-- or you hurt the spell." - The Wicked Witch of the West.
"We've got the torpedo damage temporarily shored up, the fires out and soon will have the ship back on an even keel. But I would suggest, sir, that if you have to take any more torpedoes, you take 'em on the starboard side." Pops Healy, DCA USS Lexington.