BREWER, Maine — One of the modules that local Cianbro workers constructed for a $7 billion oil refinery expansion in Texas has already been fastened into place at the refinery, a company spokesman said Monday.

Four modules — heavy-duty industrial steel frames filled with pipes, pumps and electronics — left Brewer in March and were unloaded on Wednesday at the Motiva Enterprises LLC oil refinery in Port Arthur, Texas, said Cianbro spokesman Alan Grover.

“One of those modules went immediately to the site and that one got locked down onto the pad” that day, he said.

Another module was rolled into place nearby but awaits pipe prepping before it is installed, Grover said.

Motiva hired Cianbro to deliver 53 refinery modules for its $7 billion expansion of the refinery, which is the largest capital investment ever undertaken in Texas.

The First of 53 Cianbro modules hauled to expanding refinery, which produces Shell Oil brand products, processes about 275,000 barrels of fuel a day and should be able to more than double production once the expansion is complete in 2010 or 2011.

To prepare for the modules, Port Arthur public works crews installed swiveling traffic lights that can be moved out of the way so “these huge modules can go right down through the middle of Port Arthur,” Grover said.

Grover said about 350 of these modules are needed for the expansion. “The town will be a module highway for a while.”

Cianbro chose the Brewer site of the shuttered and contaminated Eastern Fine Paper Co. mill, which closed in January 2004, for its Eastern Manufacturing Facility. It spent 10 months transforming it into a module-producing facility that employs about 400 skilled laborers. Another 70 or so work at a pipe fabrication plant in Bangor.

Access to the river is needed to move the refinery modules, which can weigh up to 700 tons and are too big to travel on highways or by rail.

Three of the first four modules delivered are about 120 feet long, 60 feet wide and 50 feet tall and the largest weighs 650 tons. The fourth is about half the size of the other three. Cianbro is scheduled to deliver the remaining 49 modules over the next 14 months. The other module manufacturing facilities that are contributing components to the refinery expansion are in Corpus Christi, Texas; Charleston, S.C.; and Tampico, Mexico.

The Columbia Boston, a 94-by-354-foot barge, pulled by the tug Emma Foss, delivered the Brewer modules to the Gulf of Mexico and already is on its way back to Maine with other components.

Two items, known as pressure vessels, are too large to transport by land, Grover said, with the components weighing about 80,000 pounds each.

The barge left Port Arthur on Thursday and is expected to arrive in Maine in about three weeks.

“Cianbro crews are nearing completion on the next four modules scheduled to be transported to Texas,” Grover said. “Those modules are expected to depart Maine via oceangoing barge during the first part of June.”

Scott Clements, Cianbro’s project manager in charge of loading and unloading the massive modules, said everything went “as smooth as silk” during the first delivery, Grover said.