Support Beams Cited in Fall of Jumbotron

The two main support beams for Anaheim Stadium’s Sony Jumbotron scoreboard were thinner at a crucial point than designers specified, which caused them to collapse during last month’s earthquake, an engineer for Jumbotron said in a report released Tuesday.

Bernard C. Adams, a Garden Grove engineer who helped design the huge scoreboard’s structure for White Way Signs of Chicago in 1988, said Tuesday that his recent examination of the board’s steel support system showed that a key portion of each beam was significantly smaller where it joined the stadium’s main superstructure.

He said this flaw, dating from the stadium’s expansion by the construction firm of Skidmore, Owings & Merrill, meant the beams could not support the 17 1/2-ton scoreboard’s weight when it began shaking during the Jan. 17 earthquake. The falling scoreboard crushed or damaged about 1,000 seats in the stadium’s upper deck in left field.

“It looks like the frames on the building were not built the way (Skidmore’s) plans showed them,” Adams said. He made his examination the week after the earthquake and on Jan. 24 submitted his report to the city, which released it Tuesday.

Adams said the support beams’ flanges, the rims that project from the top and bottom of a beam to give it strength, were supposed to be 2 inches thick by 18 inches wide throughout the beams’ lengths. He said that he did not make exact measurements of the flanges, but that photos show the flanges reduced in size significantly as they came into the stadium’s main frame.

Skidmore officials were unavailable for comment Tuesday.