One test was conducted Sunday and others may follow this week as federal engineers in Vicksburg continue trying to determine exactly why levees failed in New Orleans.

Sunday, engineers gathered to watch a centrifuge spin a tiny model of the 17th Street Outfall Canal.

Later this week, tests may be conducted on a 14,000-square-foot model – about a third the size of a football field.

&#8220They turned that model over Friday,” said Wayne Stroup, a spokesman for Engineering Research and Development Center.

He said the larger model will likely be flooded with water today and engineers will probably begin testing, using data, along with that from the centrifuge and other tests, to draw conclusions.

New Orleans was flooded after Hurricane Katrina hit on Aug. 29, not because water overtopped the network of levees and walls that protect the city, although that may have happened. The larger problem was failures in which structures gave way or were undermined.

Determining the flaw or combination of flaws has been deemed essential by an interagency task force that commissioned the work here under the auspices of the U.S. Army Corps of Engineers.

Speaking of the public works department employees who built the large model, Stroup said, &#8220They did a tremendous job, working 12 hours a day seven days a week. This was a crunch project because we have a deadline of June 1.”

The same was said on National Public Radio today of the test in the smaller centrifuge model, which yielded data to be analyzed in days and weeks to come.

The centrifuge, similar to those used in astronaut training to test the effects of increasing gravity, is three stories below ground. It was manufactured in France and installed at the federal research station here more than 10 years ago. It remains one of the largest in the world.

Increasing gravitational forces on objects can show scientists the effects of time and stress. ERDC also uses computer programs to conduct the same type of analysis along with physical modeling.

In the model expected to be used this week, 1 foot on the model reflects 50 feet. It is in the J.V. Hall Building which can be seen from Halls Ferry Road across the street from the Raworth YMCA Building and cost $325,000 to build.

Stroup said engineers and scientists from the Coastal and Hydraulics Laboratory located in the ERDC compound have designed the tests. The data supplied by the model will be used in developing computerized, numerical models that can be used in studying the other breaches in the levees surrounding New Orleans.

The model depicts the 1.2 square miles surrounding the 17th Street breach, including the nearby Old Hammond Highway Bridge to 1,200 feet beyond the breach site.

Two large wave generators will be used to simulate the waves and water movement in Lake Pontchartrain that are believed to have contributed to the wall’s failure.