Manual Damage Assessment

Department of Defense
Office of Civil Defense

In the opening scene of this dryly titled film, personnel at Castle Rock Airport call into the local civil defense headquarters to describe a brilliant flash and tremendous roar to their immediate Southeast.  Taking this report over the phone, building inspector Larry Boyd and county engineer Ralph Harris quickly plot data on a large map grid.  When the airport's information is pinpointed with other eyewitness accounts of a similar flash, the two men are able to determine that a nuclear missile has detonated over the nearby town of Glenwood Springs, population 3,687.  There is no time for grief, however, as the destruction of of Glenwood Springs must be passed on to the Emergency Operating Center so civil defense staff can calculate how this loss of resources will affect the surviving portions of the county.  A voice-over narrator explains that Boyd and Harris are performing Manual Damage Assessment, a vital task in the hours following a nuclear attack on the United States.  If contact is lost with a city due to a suspected nuclear strike, manual damage assessment is the process of coordinating eyewitness reports from the surrounding areas to determine what has happened and how much destruction has taken place.  A scrolling disclaimer warns that this practice should only be utilized when direct communication with a target area is not possible, as initial eyewitness reports likely have a high degree of error.

The Office of Civil Defense released Manual Damage Assessment in 1967 to train volunteers in how to best estimate the destruction caused by a nuclear attack using only scattered first-hand accounts.(1)  The film is presented as an exercise which walks the viewer through each step of the assessment process while providing tips to achieve the most accurate results.  When assembling his assessment team, civil defense director Harold Young uses local professionals with an intimate knowledge of the region.  Harris and Boyd are selected for their ability to read maps, mathematically calculate the size of nuclear detonations and plot relevant data on maps.  Maps prepared by the U.S. Geological Survey or the Army Map Service are ideal.  They should be pre-plotted with the locations of resources before any emergency arises.  This is the first of five categories of information which must be determined for proper damage assessment, the location, type and amount of resources in an targeted area.  The second category asks when, where and how large the nuclear detonation was while the third category deals with how the weapon was delivered.  The fourth category attempts to list any actions which are taking place to mitigate damage and the final category records meteorological conditions to help chart fallout radiation patterns.  To obtain this information, unconventional sources must be considered.  Provided they survive the initial blast, forest ranger towers, small aircraft pilots, radio station disc jockeys and air traffic controllers are suggested observers with readily available communications equipment who may be relied upon.

Similarly, Harris and Boyd rely on improvised techniques  to determine the size and strength of a nuclear detonation.  Counting the seconds between a bright flash and a roaring blast allows them to roughly calculate a weapon's yield in megatons.  An appropriately sized overlay sheet of concentric circles is then placed on a target area map and the levels of destruction can be estimated.  When their assessment is complete, Harris shares  their findings with each department in the emergency operating center.  The actor playing Ralph Harris is Chris Bohn, best remembered today for his role in The Doctors and commercial work.  He would also make a career of starring in short, instructional style films covering everything from tire safety to a television announcer discussing a nuclear crisis.  The set of the emergency operating center would be reused for many Office of Civil Defense productions from 1967 including Introduction to a Radiological Defense Exercise, Emergency Operating Centers: Radiological Defense Operations and Display of Operational Data. The technical procedures presented in Manual Damage Assessment would not be deemed obsolete by the end of the 1960's.  Instead, the film could be rented or purchased from Defense Civil Preparedness Agency (successor to the Office of Civil Defense) catalogs into the 1970's.(2)

Manual Damage Assessment may be viewed, in its entirety, HERE.

1. Index of Army Motion Pictures and Related Audio-Visual Aids. Department of the Army. December 1972. P. 55.
2. Index of Army Motion Pictures and Related Audio-Visual Aids. Department of the Army. December 1972. P. 55.