A Pennsylvania water tank project with an estimated cost of $2.225 million suffered a potentially disastrous setback when it was hit by a freak storm, but tank builders worked together to repair the damage and make the tank stronger than ever.
The 1997 tank project was one of the most ambitious - not to mention most expensive - in the memory of Oxford Borough officials. The projected cost just about equaled the entire annual budget of the tiny Pennsylvania municipality. When the project was completed, the Borough would have 9,000 linear feet of new 12 inch water pipe mains and, most prominent of all, two new aboveground steel water storage tanks. One, standing 24 feet high by 73 feet in diameter, was a reservoir tank intended to store 750,000 gallons of raw water. The second, at 88 feet high by 54 feet in diameter, was a standpipe with a 1.5 million-gallon drinking water capacity.
The raw water storage tank was already finished when disaster struck the standpipe project about five weeks from completion.
On the Saturday afternoon before Easter Sunday 1997, the tank had reached an elevation of 64 feet when a freak storm from the south came whipping through the borough, packing wind gusts as high as 60 mph. Within minutes, wind had crumpled the top of the partially completed standpipe - leaving damage, a local newspaperman wrote, that appeared to be inflicted by a giant karate chop.
In short order Borough Manager Jon Walker was on the scene, accompanied by David Bright of Spotts, Stevens & McCoy, the boroughs consulting engineers, and James Miller and Joe Boutin, vice presidents for Fisher Tank Company, the contractor for the project.
The first order of business was to evaluate site safety. All agreed there was no danger to nearby properties or passersby. As Bright put it, could the tank further deform?
"We were satisfied," concluded Miller, "that there would be no further damage to the tank. The site inspectors then turned their attention to the damage itself. An aboveground storage tank is at its most vulnerable while under construction."
Since the tank wasnt finished, explained Miller, obviously there was no water in it to support the shell. Had it been shorter or even taller, it might have withstood the wind better.
The following day, Easter Sunday morning, Fisher Tank management convened a meeting of its emergency response team at the companys Chester, Pa., headquarters. Under the direction of President Leo Pasini, the group of managers, engineers and field personnel mapped out a plan of remedial action.
Fisher and the borough-consulting engineers made their initial damage assessment Monday.
In at least one respect, the borough and its contractor were fortunate. Construction of the standpipe called for the successive installation of eleven rings of steel plates; each ring had six plates 28 feet long by eight feet wide. Since the water pressure exerted against the inside of a storage tank is greater at the base than at the top, the steel plates in the lower rings are thicker than those in the upper rings.
When the storm hit, eight rings had been installed; of these, plates in rings five, six, seven and eight had sustained damage. Project specs called for all plates in rings eight through eleven to be an identical .25 inch thick; they were interchangeable and a supply already was on hand.
That meant, explained Miller, that the crew could use the leftover .25 inch plates to complete work on rings eight through 11 while waiting for the steel supplier to ship the thicker plates needed for the lower rings.
Six days after the wind had whipped through the borough, the tanks field crew was welding lugs to the damaged steel plate, affixing cables to the lugs and exhorting a giant crane to pull out the collapsed steel plates.
The new tanks had been slated to go on line in September, a date that was fast approaching. The storm threatened to set back the completion date by three to five weeks.
During a state-of-the-tank meeting, Miller appeared before the council and its consulting engineers, outlining his companys remedial plan and answering questions. Much of the discussion focused on the creases in the steel plate. When steel creases, there is a potential for weakening which metallurgists call yielding. After some initial disagreement on the number of plates requiring replacement, Fisher agreed to install seven new 28 foot x 8-foot-plates.
Despite the early prediction of a 3-5 week delay, the project was completed on schedule.
It was, said Miller, a kind of coming together of hard work, a cooperative effort among borough officials and a responsible contractor, and a few good breaks.
Walker and Bright concurred. "We had some good talks and reached a satisfactory solution," Walker said. "Right from the start," added Bright, "Fisher representatives agreed, for the most part, with the assessment."
