History
From the Archives: March 29, 1956
This 1956 image depicts the world record, long-span, glue-laminated timber arches being assembled for a 3,500-seat jai alai fronton in West Palm Beach, Fla. The arches had a clear span of 242.5 ft, a rise of 74 ft, and a circumferential length of 294 ft.
Each of the 11-in.-thick arches widened from 25 in. at the base to 46 in. at the crown, were spaced 16 ft apart, weighed over 15 tons and contained 17,000 board ft. Wood was chosen because of economy and ease of erection.
Plywood templates were constructed to the exact size and shape of the arches, and used to set gluing forms and later in trimming the members. Given the large size of the templets a nearby airport was used as the layout floor for pattern construction.
The arches were fabricated by Unit Structures, Inc. in Wisconsin and shipped to Florida in four sections to meet railroad clearance requirements. The lamina were made with 2x12-in. southern pine. The longest lamina were over 90 ft.
The worker is hammering the pin in the welded steel hinge at the crown. One of Unit Structures partners, Max Hanisch, a German architect and engineer, brought the glulam process to the U.S., which had been invented and patented in 1901 by Otto Karl Freidrich Hetzer, a German carpenter and inventor.
The fronton was destroyed in a fire in 1978.
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