SPORT MOVES UNDER A BIG TOP

Handsome domed structures are springing up on campus like plastic mushrooms, replacing the ill-lit barns that once functioned as field houses and gymnasiums. Above: the Harvard tennis team practices in the evening under the 40-foot-high blue vinyl sky of a $250,000 dome. It has three clay courts, is in use night and day, summer and winter.

Two translucent bubbles at the coed Forman School, Litchfield, Conn., can be rigged up for bad weather by the students in a couple of hours. They are inflated and held aloft by a pair of 1½-horsepower fans. The bubble seen at right, with the shadows of trees visible through the vinyl-coated nylon, covers an Olympic swimming pool, and the one below, a tennis court with a surface of vinyl grass stuck to an asphalt base. After 13 months' hard play (it is used for volleyball, badminton and basketball, too) it shows no signs of wear. A bubble-covered tennis court costs around $25,000, including $10,000 for the nylon fabric and portable grass at $1.20 a square foot. Forman is planning a third bubble, four times as big, to cover a 220-by-115-foot hockey rink.

Asymmetrical gymnasium building at Carleton College in Northfield, Minn. is the ingenious creation of controversial Architect Minoru Yamasaki. The thin-shelled roof-called the potato-chip top by the unconverted—is reinforced concrete, and the walls are faced with beige brick (right). Vaults of poured concrete span a two-story gymnasium measuring 249 feet by 122 and, in a separate section, an indoor swimming pool with seats for 300. The gymnasium proper (shown at left with wrestling in progress) has wooden bleachers seating 1,800 and a bouncy floor, cushioned by thousands of two-inch-square rubber sponges. The bleachers fold away and there are two basketball courts. The entire structure cost $1.1 million.

Prestressed concrete has proved a magic substance in the hands of Pier Luigi Nervi, who designed the lively circular sports palaces at the Rome Olympics. His special use of the material is admirably adapted to the needs of sports stadiums and field houses. For Dartmouth College in New Hampshire, Nervi designed a rectangular field house 62 feet high and almost as big as two football fields. It has a huge dirt-floor practice area for baseball and football, separate space for lacrosse practice and golf-driving nets, a removable 11-lap board track for indoor track meets and seating for 3,500. At right: Halfback Tom Spangenberg is kicking for the ribs of Nervi's $1.5 million concrete umbrella.

SIX PHOTOS

MARVIN E. NEWMAN