Logan bridge passes inspection

Freedom Newspapers: Chelle Delaney State Department of Transportation officials inspect the bridge on U.S. 54 at Logan. From left are state bridge inspector Carlos Martinez, bridge engineer Heather Sandoval, student intern Gillie Lopez and patrol foreman James Evans.

By Chelle Delaney: Freedom Newspapers

State bridge inspectors gave the bridge on U.S. 54 near Logan passing marks on Thursday after spending several hours examining its structure.

The bridge is one of four steel-truss bridges in New Mexico Gov. Bill Richardson ordered to undergo a comprehensive inspection. Richardon’s order was prompted by the deadly bridge failure in Minneapolis.

“It’ll be a ‘5,’ ” said Heather Sandoval, assistant district engineer and bridge engineer with New Mexico Department of Transportation.

A “5” rating means the bridge’s condition is fair – “all primary structural elements are sound but may have minor loss, cracking, spalling or scour,” according to federal guidelines for bridge inspection.

“Spalling” or “scour” refers to defects in the concrete almost like a pothole or blister, said Sandoval.

Bridges are rated from “9” for excellent condition to “1” for “imminent” failure condition. A “0” means the bridge is out of service.

Next month, the bridge will have its annual inspection conducted by New Mexico State University at Las Cruces, Sandoval said.

At that time every rivet will be checked out, with a university crew that will use a bucket anchored atop the bridge, Sandoval said.

Thursday’s bridge inspection was visual with the use of binoculars.

If the bridge needs further examination, a crew will come out with ladders, Sandoval said.

When a bridge reaches a “2” rating, it is immediately shut down and closed to all traffic, Sandoval said.

A “2” is described as a bridge in critical condition with “advanced deterioration of primary structural elements.”

The Logan Bridge was opened in June 1954.

Bridge ratings
9: Excellent condition

8: Very good condition — no problems noted.

7: Good condition — some minor problems.

6: Satisfactory condition — structural elements show some minor deterioration.

5: Fair condition — all primary structural elements are sound but may have minor loss, cracking, spalling or scour.

4: Poor condition — advanced section loss, deterioration, spalling or scour.

3: Serious condition — loss of section, deterioration, spalling or scour have seriously affected primary structural components. Local failures are possible. Fatigue cracks in steel or shear cracks in concrete may be present.

2: Critical condition — advanced deterioration of primary structural elements. Fatigue cracks in steel or shear cracks in concrete may be present or scour may have removed substructure support. Unless closely monitored it may be
necessary to close the bridge until corrective action is taken.

1: “Imminent” failure condition — major deterioration or section loss present in critical structural components or obvious vertical or horizontal movement affecting structure stability. Bridge is closed to traffic but corrective action may put back in light
service.

0: Failed condition — out of service, beyond corrective action