"There are some challenging logistics," Bertucci says. "They let us know when they move the animals around. We also carry radios in case there's a code red and an animal escapes."

Old Utilities, High River Levels

Bertucci says the contractor also discovered old subsurface utilities. Gibbs is building the project in an area of zoo property that has been out of the public domain and relatively untouched for 100 years. Excavating down 10 ft to 14 ft in some areas, crews found pipes and conduits that had been in place for over a half-century, some belonging to companies that don't exist any more.

"We had to reroute a lot of things around: fiber optics, communications, utilities, gas, water, sewerage, you name it. It took six months [to get some things moved]," says Dorand.

Bertucci says the delay consumed much of the project's float time. While waiting for the utility relocations, Gibbs used a skeleton crew to do as much surface work as possible. The utility work pushed pile-driving and excavation work into the winter, which happened to be one of the coldest winters in recent years in New Orleans. Site issues further compounded the schedule. Because the site sits within 1,500 ft of the Mississippi River, the team needed special permitting from the Orleans Parish Levee Board to excavate. When the river water rose above 11 ft, crews had to stop and backfill until the water receded.

"We were shut down at one point for another three months during high river conditions," says Bertucci. "Combined with the [utility work], it added some big delays."

Unique Design

Behind the decorative facades, animal exhibits can have some interesting designs with atypical construction features. Dorand says because elephants are highly inquisitive diggers, any utilities that ran through their exhibit had to be buried deeper than normal. And because orangutans are 10 times stronger than humans, any welds in their cages had to meet higher stress tests. Even bolts had to be torqued tighter. The simplest things such as an exposed conduit or shallow pipe in the ground could be ripped up by curious, powerful animals.

"You have an odd factor in [zoo exhibits] where you have to go above and beyond what you might do in an office building or ordinary facility," Dorand says.

Deepening the moat was a challenge because it lay between a historic building and a pathway for visitors.

To handle some of the complex features involved with zoos and water parks, Gibbs brought in a number of specialized subcontractors, including COST of Wisconsin Inc., Jackson, Wis., a specialized construction builder of zoo exhibits, water features, themed buildings and mini golf courses. Chris Byers, COST project manager, says the firm is working on themed features on all three projects, including 10,000 sq ft of faux rockwork. COST brought six of its employees to New Orleans for its work, which is expected to take six months.

Byers says rock features for the elephant exhibit had to be specifically engineered to withstand the weight and activity of the massive animals. COST constructed steel "cages" at one of its two plants in Wisconsin and shipped them to the site. Once the area is ready, cages will be placed in their designed pattern and COST specialists will fill them with concrete and add the finish layers.

"In areas where the elephants are, we strengthened the rockwork with No. 4 rebar 12 inches on center," Byers says. "The basic stuff is relatively simple, but making it look like real rock is an art form and takes great skill."