PORTSMOUTH - The first span of the new Memorial Bridge will be floated into place this morning.

The 300-foot south span of the bridge has been under construction on the barge Cape Cod at the state pier on Market Street since early fall.

Around 9 a.m. the barge will leave the state pier and move downriver slightly past the bridge site where it will turn and approach the rebuilt bridge piers from the east. The span will be 18 feet off the deck of the barge as it approaches the new piers.

Crews from Archer Western, the main contractor on the project, will position the barge between piers one and two, as close to pier two as possible given the low water level close to shore.

As the tide rises, the span will be positioned close its final location over the piers. Once in position, the crew will adjust the span's elevation using a temporary jacking system to lower the span onto the bearings on top of each pier. The span must be placed within a one-quarter-inch margin of error, according to information provided by Archer Western on Monday.

The Cape Cod will be moved out from under the new span during Tuesday evening's low slack tide and return to the Port Authority Pier, where assembly of the north span will begin.

The north span is scheduled to be placed sometime in March.

Once the south span is in place, Archer Western crews will begin to assemble the 18-foot south tower on site. The new Memorial Bridge is scheduled to be open to traffic by July.

More information is available at the project's website, www.memorialbridgeproject.com.

gmacalaster@newstote.com