A fire control tower is a structure located near the coastline, used to detect and locate enemy vessels offshore, direct fire upon them from coastal batteries, or adjust the aim of guns by spotting shell splashes. Fire control towers came into general use in coastal defence systems in the late 19th century, as rapid development significantly increased the range of both naval guns and coastal artillery. This made fire control more complex. These towers were used in a number of countries' coastal defence systems through 1945, much later in a few cases such as Sweden. The Atlantic Wall in German-occupied Europe during World War II included fire control towers.
World War II-era fire control tower at Fort Saint Elmo, Malta
Two typical fire control towers on Swallow Cave Rd. in Nahant, Massachusetts, known during WW2 as Site 131. Site 131-1A is on the right in this photo. Built in 1943-44, these twin towers watched over the northern approaches to Boston Harbor and directed the guns of several different Coast Artillery batteries. Towers similar to these can be found today in all coastal New England states.
Observing instruments used in fire control towers
A plan of all the floors of Nahant Site 1A
Coast Artillery fire control system
In the U.S. Army Coast Artillery Corps, the term fire control system was used to refer to the personnel, facilities, technology and procedures that were used to observe designated targets, estimate their positions, calculate firing data for guns directed to hit those targets, and assess the effectiveness of such fire, making corrections where necessary.
In this plotting room, the table is a Whistler-Hearn plotting board. A range correction board is on the left rear of the table.
A conceptual diagram of the flow of fire control data in the Coast Artillery (in 1940). The set forward point of the target was generated by using the plotting board (1). This position was then corrected for factors affecting range and azimuth (2). Finally, fire was adjusted for observations of the actual fall of the shells (3), and new firing data were sent to the guns.
A series of observed positions (blue circles) establishes the likely track of the target. Using a plotting board, the set forward point is determined, based upon the target's observed course and speed and an assumption about when the gun is to be fired.
This example shows the relationship of steps in the fire control process playing out over time.
