Near the end of the Cold War, the United States Military grew concerned about its equipment’s capabilities to withstand the effects of an electromagnetic pulse. Out in the middle of a giant pit in the desert in Albuquerque, New Mexico, the government built a giant wooden structure named ATLAS-I. Standing for Air Force Weapons Lab Transmission-Line Aircraft Simulator, this massive ominous structure was built between 1972 and 1980 to validate the united states security against an EMP attack.
Electromagnet pulses, or EMPS, are intense bursts of electromagnetic energy often resultant of an aerial nuclear explosion. Militaries of past and some still present considered using these weapons to inflict damage upon electrical and electronic systems of opposing countries. EMPs do that through the high current and voltage surges created through the initial blast that burn out all sensitive components in electronics nearby. Back in the 1980s this would have been bad news for the US, or any country for that matter – but in 2019, this would practically bring the modern world to a standstill.
Communication would be nearly impossible, cars and planes wouldn’t work, phones wouldn’t work. Nothing about our modern life would work…
It’s this fear that the US ultimately capitulated to near the end of the Cold War causing them to build the ATLAS-I testing center.
Also known as the Trestle, this center was specifically designed for testing electronic machines against EMP blasts, but to understand a little more about why such a center was built, we need to step a little further back into the heat of the Cold War.
EMPs have been a known and understood weapon since early nuclear tests in the 1940s. In 1945, when the US was getting ready for their series of Trinity tests, physicists advised the Army to take precautions to protect their electronic equipment. Even still, many recordings of those tests were fried from the blast.
1962 marked the most prominent EMP test for the US where they conducted a high-altitude nuclear test. Named “Starfish Prime” this test involved the detonation of a bomb weighing in at 1.44 megatons over the Pacific Ocean about 400 kilometers up in the sky. The resultant EMP blast knocked out streetlights over 1400 kilometers away, set off alarms, and damaged other electronics. In the following days to months, several low-earth satellites actually failed due to radiation damage. It was after these unplanned effects from the EMP were seen that the US government and military became acutely aware of just how damaging an EMP blast could be…
Over in the Soviet Union, EMP tests were also being conducted – after all, it was the heat of the Cold War. In 1962, the same year as the US’s famous Starfish Prime test, the Soviets detonated a 300 kiloton bomb, roughly 4 times as small as the US’s bomb, over Kazakhstan. The Soviets set up a 570-kilometer long telephone line fitted with sensors and overvoltage protectors on a regular interval. The EMP blast caused every sensor to trip.
It also set an electrical power plant on fire many miles away thanks to induction that occurred in a 1,000 km long buried transmission cable. While the Soviet Bomb was much smaller than the Starship Prime test, it caused much more damage due to it’s positioning over land.
Both the US and the Soviet Union grew increasingly fearful of EMP attacks from the other as they were more aware than ever of just what they could do. An EMP could knock out an entire Navy fleet. It could disable an airbase. It could cause an immeasurable amount of damage.
The US Army became obsessed with hardening all of their military hardware making sure that it could withstand EMP blasts. They built 18 different test facilities at air force bases all over the US. Each testing center focused on the same principles: aircraft were parked on the ground and a short burst of electromagnetic radiation was blasted right at it. After that, engineers studied the aftermath.
The problem was that this EMP generated from high energy transmission reflected off of the ground under the aircraft causing the vehicles to be exposed to 2 times the amount of radiation they would absorb if flying. This is where the ATLAS-I testing center comes into play.
ATLAS-I was specifically designed to mitigate this radiation reflection from the ground. Engineers built a giant wooden platform over a bowl-shaped indention in the desert floor. This platform made up the bulk of the ATLAS-I test structure and was made of wood and fiberglass so that it didn’t interfere with the electromagnetic pulse.
Measuring 200 feet by 200 feet, it also had a 400-foot long towpath and came in at a height of 12 stories. All of this careful design and placement meant that it could simulate an EMP blast on an airplane while stopping any radiation reflection from the ground. It was the perfect test site for military aircraft.
Planes would be towed onto the entirely wooden and fiberglass platform and placed to wait for an EMP blast. A pair of MAX 5 megavolt generators, one mounted on each side, were used to produce the short-range EMP burst. When combined, they could produce a 200-gigawatt pulse of electromagnetic pulse. At short range, this was equivalent to the pulse from a thermonuclear explosion.
Over the ATLAS-I’s operational years from 1980 to 1991, the Trestle was used to test massive bombers, fighters, and even missiles against EMP attacks.
In 1991, at the end of the Cold War, the ATLAS-I test site was finally shut down, but the structure still stands as a national monument that can be seen today,