The test took place on June 27, 1985 at the White Sands Missile Range in the state of New Mexico. 4.8[1][2] thousand tons of ANFO (ammonium nitrate and fuel oil) explosive, equivalent to 4 kilotons of TNT,[3] were used to roughly simulate the effect of an eight kiloton air-burst nuclear device. Minor Scale was reported as "the largest planned conventional explosion in the history of the free world" [1]. It is rated as second to the 'British Bang' disposal of ordnance on Heligoland in 1947 by the Guinness Book of Records, but this appears incorrect. ( According to [4] the energy released at Heligoland was 1.3x1020 ergs = 1.3x1013 joules, or about 3.2 kilotons of TNT equivalent. )
The purpose of the test was to evaluate the effect of nuclear blasts on various pieces of military hardware, particularly new—and nominally blast-hardened—launchers for the Midgetmanballistic missile[2].
QUESTIONS AND ANSWERS (from the non-copyright report)
Q: Why is photography not allowed? A: Individual or press photography is not allowed because of numerous classified experiments on the test.
Q: How much did the MINOR SCALE program cost? How much of that was for ANFO? A: The cost to prepare the test bed, provide diagnostic instrumentation and logistical support, is 7 million. Cost to test and evaluate the approximately 300 experiments is estimated at 30 million, ANFO cost approximately 1.1 million.
Q: What type of eyppriments are on the test bed? A: Experiments on MINOR SCALE range from measurement of air and ground shock waves caused by the blast to recording and documenting the blast and thermal effects on different types of shelters, buildings, antenna systems, a wide range of military equipment and protective clothing, and equipment on anthropomorphic mannikins. Pictures of most of the experiments are displayed at the Observation Post.
Q: How much TNT is 4800 tons of ANFO comparable to? A: 4800 tons of ANFO is equivalent to 4000 tons of TNT.
Q: What size nuclear explosion is MINOR SCALE comparable to? A: MINOR SCALE was designed to simulate the airblast effect from an eight kiloton nuclear detonation.
Q: Why do you use ANFO? A: ANFO is being used because it is currently the most cost effective explosive available. It is also very safe to handle. Research programs are ongoing to determine if more suitable and cost effective explosives can be developed.
Q: Is ANFO harmful to the environment? How do you return the area to pre-test conditions? A: Upon detonation most of the ANFO is consumed leaving little residue. After salvagable test articles and other materials are removed from the test bed, all debris is picked up and put in a sanitary landfill.
Q: How do you get 4800 tons of ANFO to explode all at once? Can it happen accidentally? A: A 100 pound octal booster is centered in the ANFO to uniformly ignite it. Accidental detonation of the ANFO is extremely remote.
Q: How many simulated nuclear explosions have been conducted at WSMR? A: DNA has conducted three previous nuclear simulation tests at WSMR: DICE THROW in 1976, MILL RACE in 1981, and DIRECT COURSE in 1983.
Q: Have you scheduled more tests like this for WSMR? A: Yes, more tests are currently scheduled at WSMR starting in 1986 and each year following.
Q: Why did you establish the Permanent High Explosive Test Site at WSMR? A: The Permanent High Explosive Test Site (PHETS) was established at WSMR to provide a cost effective, reusable high explosive test facility.
Q: Can we go down to see the test bed either before or after the explosion? A: The test bed will be closed the day before execution because of final test preparations. Post test observations will not be allowed until the day after detonation due to safety and security considerations.
Q: How far away will be blast be heard? A: Atmospheric conditions greatly affect how far and where the blast can be heard. On MILL RACE for example, the blast was heard several hundred miles away. Towns adjacent to WSMR will likely hear the blast.
Q: How is a test like this related to nuclear weapons? A: The high explosive test simulates the blast from a nuclear weapon, and the thermal radiation source simulates the thermal radiation from a nuclear weapon.
Q: How long before we hear the blast and feel the shockwave at the observation point? A: About 40 seconds as the Observation Post is approximately 8 miles from ground zero and sound travels 1060 feet per second.
Q: What is ANFO? A: ANFO is an acronym which stands for Ammonium Nitrate Fuel Oil. It is an explosive composed of Ammonium Nitrate (Fertilizer) containing 6% fuel oil.
Q: Why is MINOR SCALE scheduled in the Summer and not the Fall? A: The test has been scheduled for June 84 to minimize the chances of lightening affecting test bed equipment such as recording gauges. Lightening storms are more frequent in the July-October time frame.
Q: Why is the test called MINOR SCALE? A: The test name MINOR SCALE has no special significance. There are no plans for a test called MAJOR SCALE. The next test to be conducted in June 86 is called MISTY PICTURE.
Q: Why is MINOR SCALE larger than DIRECT COURSE? Will future tests continue to get bigger? A: MINOR SCALE was planned to simulate the battlefield environment. Future tests are not projected to get bigger than MINOR SCALE.
