VERONA – Acoustic monitoring devices have detected three wire breaks in the main cables of the Waldo-Hancock Bridge during the past week and a half, according to state transportation engineers.

The breaks occurred in noncritical areas of the bridge’s main cables and are not considered a major problem on the 72-year-old structure, according to Maine Department of Transportation Project Manager Devin Anderson.

Deterioration in the main cables has reduced the bridge’s safety level, forcing the DOT to post a 12-ton weight limit.

“The breaks were not in critical areas,” Anderson said Monday. “There are four areas on the cables with the worst deterioration. The breaks did not take place in those areas.”

After the posting, the department installed acoustic monitoring devices at 11 locations on the north and south main cables in order to monitor conditions 24 hours a day. The cables consist of 37 smaller cables, each of which is made of 37 individual wire strands, for a total of 1,369 wires in each cable.

The monitors are calibrated to detect the sound of a breaking cable, record those signature sounds and relay the information to computers.

Two of the breaks took place on the south cable and the third was on the north cable, Anderson said. These are the first breaks to occur since the monitoring devices were installed last month.

Meanwhile, the contractor on the current cable rewrapping project is almost finished.

All of the suspender cables have been replaced and the concrete sidewalk has been removed and replaced with a wooden sidewalk. The contractor, Piasecki Steel of New York, still needs to add angle braces on the new sidewalk to protect it from snowplows.

The concrete sidewalk was removed to lighten the load on the bridge.

Piasecki also has begun some of the preliminary work preparing a new anchorage for supplemental cables, which the department is hopeful will help ease the load on the existing cables.

The DOT has hired Cianbro Corp. of Pittsfield to install the supplemental cables, a job that is expected to cost between $3.5 million and $5 million. Officials would like to have that job completed by Nov. 1.