Plotting room
Encyclopedia
A plotting room was used by the U.S. Coast Artillery to house a team of soldiers who were engaged in controlling fire for the guns of a Coast Artillery battery.
A plotting room was connected by telephone lines (and sometimes by radio) to base end station
s (at left, top) that observed the locations of enemy ships and sent data to plotting room soldiers who used equipment like a plotting board
to calculate where the guns should be pointed and when they should be fired.
Telephone lines also ran from the plotting room to the guns and were used to relay firing data. Other devices, like range correction boards or deflection boards, were used in the plotting room to calculate corrected firing data
or to adjust range and azimuth after spotters in remote observing stations had seen where prior shots had fallen.
Plotting rooms were sometimes made of concrete and buried below ground (for protection) or were located in the reinforced concrete casemates of Coast Artillery batteries. The casemated version shown at left was built into the side of a sloping embankment near its mortar battery.
Plotting rooms were also located in free-standing structures, either low towers (like two-story tower from 1904 shown in a photo and in plan view at right) or one- or two-story wood and plaster buildings which might house facilities for several batteries right next to each other in barracks-like structures. These multiple-battery installations might also have sleeping quarters and latrine facilities built nearby.
Sometimes plotting rooms were located hundreds of yards from the batteries they controlled. They often sat on top of nearby hills or ridge lines.
A plotting room was connected by telephone lines (and sometimes by radio) to base end station
Base end station
Base end stations were used by the U.S Coast Artillery as part of fire control systems for locating the positions of attacking ships and controlling the firing of seacoast guns, mortars, or mines to defend against them....
s (at left, top) that observed the locations of enemy ships and sent data to plotting room soldiers who used equipment like a plotting board
Plotting board
A plotting board was a mechanical device used by the U.S. Coast Artillery to track the observed course of a target , project its future position, and derive the uncorrected data on azimuth and range needed to direct the fire of the guns of a battery to hit that target...
to calculate where the guns should be pointed and when they should be fired.
Telephone lines also ran from the plotting room to the guns and were used to relay firing data. Other devices, like range correction boards or deflection boards, were used in the plotting room to calculate corrected firing data
Corrected firing data
Corrected firing data was a term used in the U.S. Coast Artillery to refer to firing data that had been corrected for various "non-standard conditions." This could include corrections to range and corrections to azimuth or deflection...
or to adjust range and azimuth after spotters in remote observing stations had seen where prior shots had fallen.
Plotting rooms were sometimes made of concrete and buried below ground (for protection) or were located in the reinforced concrete casemates of Coast Artillery batteries. The casemated version shown at left was built into the side of a sloping embankment near its mortar battery.
Plotting rooms were also located in free-standing structures, either low towers (like two-story tower from 1904 shown in a photo and in plan view at right) or one- or two-story wood and plaster buildings which might house facilities for several batteries right next to each other in barracks-like structures. These multiple-battery installations might also have sleeping quarters and latrine facilities built nearby.
Sometimes plotting rooms were located hundreds of yards from the batteries they controlled. They often sat on top of nearby hills or ridge lines.
see also
- Gun Data ComputerGun Data ComputerThe gun data computer is a series of artillery computers used by the U.S. Army, for coastal artillery, field artillery, and antiaircraft artillery applications...
These electro-mechanical computers were introduced into the Coast Artillery in the 1940s, particularly in the new 100- and 200-series 16-inch and 6-inch gun batteries that became operational during that period. Some of these computers received data directly from communicators that were connected to observational instruments in fire control stations or from Coast Artillery radar equipment.
External links
- http://www.cdsg.org/
- http://www.ibiblio.org/hyperwar/USA/ref/FM/PDFs/FM4-15.PDF FM 4-15