ATLAS-I

Built at a cost of $60 million, it was composed of two parts: a pair of powerful Marx generators capable of simulating the electromagnetic pulse effects of a high-altitude nuclear explosion (HANE) of the type expected during a nuclear war, and a giant wooden trestle built in a bowl-shaped arroyo, designed to elevate the test aircraft above ground interference and orient it below the pulse in a similar manner to what would be seen in mid-air.

The generators were mounted on pedestals constructed of wood in the same manner as the main test platform, one on each side of a large wedge shaped steel structure which acted as a ground plane for the horizontally polarized pulse.

When discharged through the plasma switches, the 50 trays in series could (ideally) produce up to 5 megavolts of electrical potential in a pulse with a rise-time in the 100 nanosecond range.

When triggered simultaneously the resulting EM waves from each generator combined at the sharp point of the wedge building, adding to a total electrical potential of 10 megavolts.

[4] The transmission lines were terminated into a 50 ohm low inductance resistive load mounted on a tall wooden tower at the far end of the platform.

The result was a fast 200 gigawatt pulse of electromagnetic flux powerful enough to reliably reproduce (at short range) the deleterious effects of a thermonuclear detonation on electronic circuitry as created by such examples as the HARDTACK I, ARGUS and DOMINIC I (Operation Fishbowl) high altitude nuclear tests.

A mix of Douglas fir and Southern yellow pine were used for the timbers,[4] as both showed excellent EMP transparency with the former having the best tensile strength and the latter the best weather resistance.

[citation needed] The trestle structure is visible from commercial aircraft landing and taking off from Albuquerque International Sunport, lying about one mile to the southeast of the threshold of Runway 26 at 35°01′47″N 106°33′28″W / 35.02981109416866°N 106.55767558197573°W / 35.02981109416866; -106.55767558197573.

A Boeing B-52 strategic bomber being prepared for EMP testing at Trestle in 1982.
A Rockwell B-1B strategic bomber is readied for testing at Trestle in 1989. Note the elevated Marx generator to the right, the aircraft platform in the center, the sensor towers to the sides of the platform and the resistive termination tower at the rear.
The platform was load tested by driving loaded TEREX mining dump trucks in an array across the deck. Notice Air Force 1 being tested at the neighboring Vertically Polarized Dipole (VPD) EMP test site in this 1979 photograph.
The Trestle facility under construction in 1975. The height of the termination tower was driven by the need to clear the tail of a C5A Galaxy transport.