Now all roads lead to France and heavy is the tread
Of the living; but the dead returning lightly dance.
Edward Thomas, Roads

Saturday, March 13, 2021

Sources of Frontline Intelligence: Flash Spotting

By Terrence J. Finnegan

Developed during the Great War, flash spotting [Licht-Messtellen] applied optical measurements to determine the location of enemy artillery where the guns could not be observed directly. The flashes could be observed at night as reflections from the sky. The purpose was then to call up friendly guns to destroy the enemy guns position. Theoretically this could be achieved by several observers spotting the flash from a particular gun and then plotting the intersection of the bearings.

This was extremely difficult with multiple guns firing since several observers could not be sure they were all looking at the same particular gun. The essential equipment for flash-spotting control at headquarters was the flash and buzzer board and the plotting board that synchronized the observations. 

A telephone switchboard provided connectivity to the posts. The plotting board employed a 1/10,000 map that traced each response from the posts. All calculations on identified artillery batteries were forwarded to artillery for counter-battery operations. The combination of sound ranging and flash spotting proved to be a vital part of the intelligence network in place to support targeting. Aerial reconnaissance complemented optical and acoustical sensor collection by confirming the locations through aerial photography.

Several sources cite the work of Canadian artillery officer and peace-time engineering professor, Alan McNaughton, for groundbreaking work on sound ranging and flash spotting in the Canadian Corps preparation for the 1917 assault on Vimy Ridge. Allied artillery effectively neutralized nearly all German artillery positions prior to the launch of the main assault on 9 April.

Supplemental information from Wikipedia and the Vimy Ridge Foundation

1 comment:

  1. Good information, Terry. It's something I had never thought about. Thank you!