The major components of a gun fire-control system are a human-controlled director, along with or later replaced by radar or television camera, a computer, stabilizing device or gyro, and equipment in a plotting room.

[c][4] Moreover, unlike in the gun turrets, he was steps away from the ship commander giving orders to change the course and the speed in response to the incoming reports on target movements.

From this design on, large warships had a main armament of one size of gun across a number of turrets (which made corrections simpler still), facilitating central fire control via electric triggering.

Directors high on the superstructure had a better view of the enemy than a turret mounted sight, and the crew operating it were distant from the sound and shock of the guns.

Unmeasured and uncontrollable ballistic factors like high altitude temperature, humidity, barometric pressure, wind direction and velocity required final adjustment through observation of fall of shot.

During the Battle of Jutland, while the British were thought by some to have the finest fire control system in the world at that time, only three percent of their shots actually struck their targets.

[10] During their long service life, rangekeepers were updated often as technology advanced and by World War II they were a critical part of an integrated fire control system.

The incorporation of radar into the fire control system early in World War II provided ships with the ability to conduct effective gunfire operations at long range in poor weather and at night.

[citation needed] In contrast to US radar aided system, the Japanese relied on averaging optical rangefinders, lacked gyros to sense the horizon, and required manual handling of follow-ups on the Sokutekiban, Shagekiban, Hoiban as well as guns themselves.

[12] In that action, American destroyers pitted against the world's largest armored battleships and cruisers dodged shells for long enough to close to within torpedo firing range, while lobbing hundreds of accurate automatically aimed 5-inch (127 mm) rounds on target.

Furthermore, priorities of replacements of older and less effective director systems in the crowded wartime production program were responsible for the fact the [Mark 33's] service was lengthened to the cessation of hostilities.

The development of the Gun Directors Mark 33 and 37 provided the United States Fleet with good long range fire control against attacking planes.

The Mark 37 director aboard USS Joseph P. Kennedy, Jr. is protected with one-half inch (13 mm) of armor plate and weighs 16 tons.

Stabilizing signals from the Stable Element kept the optical sight telescopes, rangefinder, and radar antenna free from the effects of deck tilt.

Although the stable element was below decks in Plot, next to the Mark 1/1A computer, its internal gimbals followed director motion in bearing and elevation so that it provided level and crosslevel data directly.

Although the train Amplidyne was rated at several kilowatts maximum output, its input signal came from a pair of 6L6 audio beam tetrode vacuum tubes (valves, in the U.K.).

The process of determining the target's motion vector was done primarily with an accurate constant-speed motor, disk-ball-roller integrators, nonlinear cams, mechanical resolvers, and differentials.

The Mark 1 computer attempted to do the coordinate conversion (in part) with a rectangular-to polar converter, but that didn't work as well as desired (sometimes trying to make target speed negative!).

Generally speaking, these computers were very well designed and built, very rugged, and almost trouble-free, frequent tests included entering values via the handcranks and reading results on the dials, with the time motor stopped.

That rotational speed and rate of mercury flow combine to put the heavier tank in the best position to make the gyro precess toward the vertical.

The gyro's drift is low enough not to matter for short periods of time; when the ship resumes more typical cruising, the erecting system corrects for any error.

Inlaid in its surface, in grooves, are two coils essentially like two figure 8s, but shaped more like a letter D and its mirror image, forming a circle with a diametral crossover.

(The sonar fire-control computer aboard some destroyers of the late 1950s required roll and pitch signals for stabilizing, so a coordinate converter containing synchros, resolvers, and servos calculated the latter from gun director bearing, level, and crosslevel.)

[1][49] The Mark 8 Rangekeeper was an electromechanical analog computer[1][49] whose function was to continuously calculate the gun's bearing and elevation, Line-Of-Fire (LOF), to hit a future position of the target.

Also, before the surface action started, the FT's made manual inputs for the average initial velocity of the projectiles fired out of the battery's gun barrels, and air density.

This was demonstrated in November 1942 when the battleship USS Washington engaged the Imperial Japanese Navy battlecruiser Kirishima at a range of 18,500 yards (16,900 m) at night.

The assistant Gunnery Officers and Fire Control Technicians operated the equipment, talked to the turrets and ship's command by sound-powered telephone, and watched the Rangekeeper's dials and system status indicators for problems.

[52] They were most effective on ships as large as destroyer escorts or larger when coupled with electric-hydraulic drives for greater speed and the Mark 51 Director (pictured) for improved accuracy, the Bofors 40 mm gun became a fearsome adversary, accounting for roughly half of all Japanese aircraft shot down between 1 October 1944 and 1 February 1945.

Mechanical connections between major sections were via shafts in the extreme rear, with couplings permitting disconnection without any attention, and probably relief springs to aid re-engagement.

It is an integral part of the Aegis combat weapon system on Arleigh Burke-class guided missile destroyers and modified Ticonderoga-class cruisers.