Radar Takes Cover Under the "Big Top"
September 1949 Popular Science

September 1949 Popular Science [Table of Contents] Wax nostalgic about and learn from the history of early electronics. See articles from Popular Science, published 1872-2021. All copyrights hereby acknowledged.

When reading this article about a 50-foot-diameter inflatable radar antenna dome from a 1949 issue of Popular Science magazine, I was surprised to learn it was only rated for withstanding 2 inches of snow. The story says snow or ice, but 2 inches of ice would typically weigh an lot more than 2 inches of snow - even wet snow. That is not to say it cannot survive in regions where more than 2 inches of snow is likely to fall. It cleverly uses a repetition of partial deflation / inflation actions to flex the surface, thereby causing the snow and/or ice to lose its grip and slide off. That sounds good in theory, but I wonder how successful it really was under real-world conditions. If you do an Internet search on some of those huge inflated sports arena domes in snowy locales, you'll find plenty which collapsed under heavy snow loads. That happened to the Erie Sports Arena when we lived there.

Radar Takes Cover Under the "Big Top"

Radar, so long kept under wraps for security reasons, now has gone under cover again. But this time it is "cover" in the literal meaning of the word - shelter to protect expensive and delicate equipment from the destructive elements of nature in extreme climates. "Radome" is the name for this balloon-like housing that is thin as paper, sturdy as steel, and does not interfere with the transmission of radar signals. Yet it is held up by air alone, with no supporting structures to get in the way of a radar set's swinging arms.

The big fellow shown on these pages is an Air Force job. It is 36 feet high, 50 feet in diameter at the base, and is made of Fiberglas™ coated with synthetic rubber. When inflated, it is strong enough to support two inches of snow or ice, and to stand up under 130-m.p.h. winds. If internal heating is insufficient to remove ice coatings, a "mechanical spanking" - a slight alternate deflation and inflation - will do the trick. For hot climes, the big bag can be air-conditioned.

Illustrated at the bottom of this page is the baby counterpart that does the same job for the Signal Corps' mobile radar units. Nine feet in diameter, this miniature version is made of Neoprene™-coated Fortisan™ rayon, which, says the Signal Corps, transmits radar signals better. It is inflated by a unit from an ordinary tank-type vacuum cleaner.

Both radomes were designed by the Cornell Aeronautical Laboratory, Buffalo, N. Y., in conjunction with the Air Force's Watson Laboratories and the Signal Corps Engineering Laboratories.

Posted February 19, 2024