The Aggie Bonfire Tragedy
(Page 2 of 4)
How can a stack of wood be so important? As everyone knows, Aggies are different. To them, A&M means not just a university but a "fantastic, heart-warming, impossible-to-describe family," as a graduate wrote in a letter published in the Bonfire memorial issue of the school's alumni magazine. That family is defined and united by a unique culture rooted in the university's history as a military and agricultural institution. Even today, when fewer than 2,000 of A&M's 43,000 students are members of the corps, military esprit and conformity run deep, as do the idealized elements of small-town life: community, tradition, loyalty, optimism, and unabashed sentimentality. The continuity of this culture has been undisturbed by the admission of women and the increase in enrollment from around 10,000 students in the sixties to more than 40,000 — and a main reason, Aggies will tell you, is Bonfire, an immense three-months-long project that introduces freshmen to the Aggie way of preserving traditions and bonding in common cause. Never mind that it destroys thousands of trees every year, inflicts dozens of serious injuries, occupies upward of 100,000 man-hours, puts some students in academic jeopardy, and calls for two six-hour nighttime shifts in addition to daytime work during Push, the last two weeks of construction. Isolated, overlooked, and made sport of for much of their school's 124-year history, Aggies long ago stopped caring whether the outside world appreciated or approved of their ways. "From the outside you can't understand it. From the inside you can't explain it" goes a popular saying on campus.
But now A&M has something it must explain, and the questions will not be easy to answer. Unlike an airplane crash, the bonfire had no black box. It did not even have a blueprint. Nor did it have professional supervision. It was a product of craft rather than science, a towering but primitive totem built according to methods that were passed on by word of mouth from one year's group of artisans (student leaders known as redpots, a reference to the color of their hard hats) to the next. In hindsight, the more that is known about the history of the bonfire, the way it is built, and the mythology that surrounds it, the less the collapse seems like a freak accident and the more it seems like an accident waiting to happen.
Two dozen or so unsharpened yellow pencils rest in Teddy Hirsch's right hand. The pencils represent bonfire logs. He taps the blunt lead ends against the desk in his home office to shape them into a cylinder, stands them straight up, and opens his fist. Thwack! Pencils fall in all directions. "When you stand logs vertically," says the emeritus professor of civil engineering at Texas A&M, "you've got no stability." He reaches for two small rubber bands and places them around the top and the bottom of the cylinder. This time the stack wobbles and tips over. He repeats the experiment, only this time he double-wraps the two rubber bands. The pencils stand. What's the difference? "Friction," says Hirsch. "With enough friction you can resist horizontal shear."
Teddy Hirsch, class of '52, is a lifelong Aggie. Now seventy, he has spent almost his entire professional career at Texas A&M, earning three degrees, including a doctorate, in civil engineering and serving on the faculty from 1956 to 1992. For 25 years he was the head of the structural engineering division. The next time you drive on a freeway and see a collision barricade made of 55-gallon oil drums, think of Teddy Hirsch: It was his idea. Tall, trim, and with the weathered face of a man who has spent a lot of time on job sites, he now works as a consultant in a room filled with engineering tools, references, and Aggie memorabilia. Ever since he moved into his house a few blocks south of campus in 1966, he has gone out to the woods where bonfire logs are cut to gather his winter firewood from the leavings. "I'm going to tell you what I tell prospective clients before they hire me," he had said when I first called him. "I don't give opinions, just facts. You may not like 'em, but they're facts. And the fact is that the layered wedding cake is inherently unstable."
Hirsch is no second-guesser. He became worried about the stability of the layered wedding cake years ago, when he noticed a pattern of bonfires' collapsing soon after being lit at eight o'clock on the night before the annual football game with the University of Texas, or as Aggies call it, t.u. "We have a saying that if Bonfire stands until midnight, we'll beat t.u.," he says. "But every layered wedding cake, to my memory, collapsed before yell practice was over. It stood for only about thirty to forty-five minutes." He aired his concerns inside the civil engineering department and conveyed them to an administrative office that oversees Bonfire. But university officials rarely interfere with student leaders unless rules are broken or assistance is sought. After the center pole bent 90 degrees during a prolonged 1994 rainstorm, pushing part of the stack over with it — no students were working on Bonfire at the time — Hirsch set up a meeting with a group of redpots to talk about safety. "I could tell they weren't interested at all," he says. "I was just another professor trying to lecture them. When I finished talking, they didn't ask any questions, they just got up and left.
"You hear people say, 'We've been building Bonfire for ninety years, and this is the first catastrophe.' Well, it's not so. This design is only twenty years old, and the center pole has fallen twice in six years." He walked over to a couch and grabbed a sheaf of papers. From university archives and old yearbooks, he has assembled a series of photographs and charts portraying the evolution of Bonfire. In the beginning, he says, Bonfire was nothing more than a pile of lumber and trash. This changed radically in 1945, the first year that Bonfire was made entirely of logs placed around a center pole. It resembled a tepee. The Aggies soon learned that they could extend the sides of the tepee to a great height by splicing the center pole and using a pulley to haul up additional logs. Bonfire reached a record 105 feet in 1969, when administrators, concerned about a fire hazard from sparks flying so high in the air, stepped in to impose a 55-foot limit.
Hirsch flips through his photographs. "Look at how the logs are leaning inward," he says, pointing to one of the tepee photos. "They're always at an angle of between 23 and 30 degrees. This design has tremendous vertical and horizontal resistance. When logs are pushed together and lean against each other, horizontal shear can be resisted." He flips again, this time to the 1984 Bonfire. The layered wedding-cake design has replaced the tepee. "Now the slope of the logs is 14 degrees," he says. The last photograph shows the ill-fated 1999 Bonfire, just a day and a half before the collapse. The logs look as vertical as fence posts. "Look at the angles of the four stacks," says Hirsch. "Zero degrees for the first stack, 4.4 for the second, zero, and zero. All that is holding the whole thing up is the center pole. It couldn't do it."
Just because a structure is unstable doesn't necessarily mean that it will collapse; even a house of cards can stand under ideal conditions. Inside the bonfire stack, the center pole and the wiring of logs to the center pole and to each other provide enough strength to overcome the static force of the weight of the logs. The problem occurs when a dynamic force develops in the stack. When a million pounds of timber starts to move, the wire ties snap as if they were made of string, and the center pole must contend with forces far beyond its ability to withstand. Not even Teddy Hirsch can identify what caused the stack to reach its breaking point. But documents that A&M has released for examination by the Special Commission on the 1999 Bonfire and by the public, including the students' witness statements, indicate several possible problems that could have contributed to the collapse, all of which remain speculative:
•The ground sloped. The area on which Bonfire was built dropped one to two feet toward the southeast — the direction in which the stack fell. This by itself wouldn't been enough to cause the catastrophe, unless . . .
•The stack was overloaded on the uphill side. Several witness statements included this observation. Witnesses reported that only one of the two cranes that brought logs to the stack had been working the previous night, and it was located on the uphill (west) side. Students standing on top of the tiers noted that the extra logs on the west side left less room for walking than was available on the opposite side. An uneven distribution of logs could explain reports on the eve of the collapse suggesting that the stack appeared to be leaning toward the downhill side.
•The stack was top-heavy. The partially completed structure had already exceeded the university's 55-foot height limit by 4 feet, with two more tiers and 16 feet left to go. Logs were still being added to the bottom tier when the whole thing fell. The second, third, and fourth levels were already well developed. Was the bottom tier capable of sustaining that much weight?
•The stack was "loose." One witness who had worked on previous Bonfires noticed that when she walked on top of a tier, her feet kept getting caught in spaces between the logs. A horticulture major, she believed that the logs were more curved than usual, making it hard to pack them in tight. A looser stack means less friction.
