Fire control tower

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This article is about a military structure to control coastal batteries. For a tower used to search for forest fires, see Fire lookout tower.

A Fire control tower is a military structure used along the American coast during World War II as an observation post to detect enemy vessels offshore and direct the fire from nearby coastal batteries. Some of these were constructed for this purposes while others could be set up inside a barn, lighthouse, or other high coastal structure to disguise it from enemy vessels.

Soldiers in a fire control tower used a Depression Rangefinder (DPF) (see picture) to determine the range of an enemy vessel and an Azimuth scope (see picture) to determine the horizontal angle. They would continually send these readings to the Plotting Room in a battery’s bunker where a mathematical formula determined the firing coordinates of the artillery.

Each tower was equipped with two powerful telescopes, one of which followed the target while the other spotted splashes of shells fired at the target so corrections could be made. The distances between these towers were recorded. Once a ship was sighted, observers took azimuth readings every 30 seconds and relied on triangulation. Together, the three lines created a triangle that could be used to determine the angle and direction that the artillery should fire.

Soldiers use a Depression Range Finder (left) and an Azimuth Scope (right) in a Fire Control Tower.

Model of a standard Fire Control Tower

Illustration of the triangulation used to control artillery fire at enemy vessels